Teklehaimanot slum upgrading, typologies for affordable mass housing

Guest lecturer: MA Sarah Abdulhafiz Yusuf, EiABC Students: Lisa Germain, Matteo Persanti, Lorenzo Piras

INDEX Sub-Saharan Africa infos Bioclimate Strategies Prof. Dr. Ing Dirk Donath Dipl. Ing Lukas Veltrusky Guest lecturer: MA Sarah Abdulhafiz Yusuf, EiABC

Parametric Masterplan Urban Strategies Urban neighborhood Urban Costs Unit design Material Report Builging Process and Costs

Sub_ Saharan Africa Some information • Population Sub Saharan Africa‘s population is set to double by 2050 and triple by 2100. Africa will be home to most of the world‘s population growth until 2100.

• Adaptation Since over 90% of agricolture in Sub Saharan Africa is rainfed and water supplies are expected to decrease and to become more erratic in most regions, local - level water management such as microcachtment, dams and tanks and smale scale irrigation from underground water will be key opportunities of adaption.

• Mitigation Limiting expansion of agricoltural lands into forest areas will be a key strategy for mitigating emissions in Africa.

• Disasters (Flood and Cyclones) Due the climate changing, the numbers of people exposed to cyclones and floods are expected to increase substantially.

• Food Waste More than 70% of food waste occurs during production and in postharvest handling and storage, while almost nothing is lost at the consuption level.

• Dietary Change Sub Saharan Africans have a low calorie intake compared to people in other regions, and a much higher proportion of their diet is made up of cereals, roots and tubers.

• Undernourischment In Sub Sharan Africa, more than a quarter of the population is under nourishment.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Addis Abeba Climate Graph (Altitude 2324 m) Addis Ababa has a subtropical highland climate (Köppen). The city has a complex mix of highland climate zones, with temperature differences of up to 10 °C, depending on elevation and prevailing wind patterns. The high elevation moderates temperatures yearround, and the city‘s position near the equator means that temperatures are very constant from month to month.

Mid-November to January is a season for occasional rain. The highland climate regions are characterized by dry winters, and this is the dry season in Addis Ababa. During this season the daily maximum temperatures are usually not more than 23 °C, and the night-time minimum temperatures can drop to freezing. The short rainy season is from February to May. During this period, the difference between the daytime maximum temperatures and the night-time minimum temperatures is not as great as during other times of the year, with minimum temperatures in the range of 10–15 °C. At this time of the year the city experiences warm temperatures and a pleasant rainfall. The long wet season is from June to mid-September; it is the major winter season of the country. This period coincides with summer, but the temperatures are much lower than at other times of year due to the frequent rain and hail and the abundance of cloud cover and fewer hours of sunshine. This time of the year is characterized by dark, chilly and wet days and nights. The autumn which follows is a transitional period between the wet and dry seasons.

The highest record temperature was 32 °C August 27, 1996, while the lowest record temperature was 0 °C on November 23, 1999.

© copyright

Lisa Germain, Matteo Persanti, Lorenzo Piras

Addis Abeba‘s Sun Path Diagram Sunrise, Sunset, Dawn and Dusk times table

Graph Sunrise / Sunset per hours in function of the month

Solar Energy and Surface Meteorology

Lisa Germain, Matteo Persanti, Lorenzo Piras

Bioclimatic Strategies Definition As a first design step it‘s important to know the climate of the project area (Addis Ababa, Ethiopia) to adopt already from the beginning the right energy strategies. It‘s possible to undertake this part of the learning using the software Autodesk Ecotect.

Before starting to analyze the data it is important to understand one of the fundamental charts that is used to decide which passive strategies were more effective: the psychrometric chart (fig.1).

Inside the psychrometric chart if the data are found in certain demarcated areas it is possible to judge the quality of a given climate.

As shown in the picture (fig.2) you can see that Addis Ababa (9.0 °, 38.8 °, practically on the equator) has a cool-temperate climate (being about 2500m high). In the program Ecotect it’s possible to see the condition of comfort for that particular climate.

In this way we can see how the data deviate from that comfort. We show the data in the summer (fig.3) and in the winter (fig.4).

As can be seen from these graphs, the climate of Addis Ababa is constant throughout the year and it is quite cool. This data can be found also from the Internet.

The psychrometric chart (fig.1)

(fig.2)

(fig.3)

(fig.4)

Lisa Germain, Matteo Persanti, Lorenzo Piras

In the Ecotect Weather Tool (fig. 5) we can see the passive strategies (shown in red). They allow you to „extend“ the comfort zone, and more they are close to the point cloud more the energy strategy is effective.

Here in particular we experience the PASSIVE SOLAR HEATING, ensuring how having 24% of the glass surface (properly exposed) would be the best solution.

You can also overlay the various passive strategies in order to compare the effectiveness (fig. 6).

Now we know that the passive strategies adapted to the climate of Addis Ababa are definitely the PASSIVE SOLAR HEATING (providing 24% of the glass surface exposed correctly) and the effects of THERMAL MASS. To verify the improvement of the energy efficiency of our building through these two passive strategies we can see the result in the graph (fig.7).

It is an improvement by an average of about 65%, using only passive strategies, thus without energy consumption.

Selecting the instrument BEST ORIENTATION, it is possible to know the preferred orientation to given to the main facade of our building (fig.8).

The yellow arrow indicates the optimum orientation, it is calculated according to the underheated period and the overheated period.

© (fig.5)

(fig.6)

© (fig.7)

© (fig.8)

Lisa Germain, Matteo Persanti, Lorenzo Piras

We can also see if it is possible to take advantage from the natural ventilation. So we can see from which direction the winds will come, at which temperature and how often. It is advisable to start considering the frequency first, and then the reliability of the passive strategy during the selected period.

In the graph (fig. 9) it is clear that the main winds come from the south and west with a temperature of 25 ° C in summer.

In winter there is a prevalence of winds from the EST with a temperature of 10 ° C (fig. 10) To get a more complete charting we can select the drop-down menu WEEKLY DATA, where 3D visualization allows us a greater quantitative understanding of the data, such as the AVERAGE TEMPERATURE, the DIRECT SOLAR RADIATION and the WIND SPEED AVERAGE (fig .11 - 12 -13).

As we can see these graphs confirm again the considerations that we did last time: at Addis Ababa, the average temperature is constant throughout the year but there is a large temperature range during the day, going to aggravated during the summer reducing the comfort (that’s why in the psychrometric chart, the situation on summer appeared more points away from the comfort of the winter). The incident solar radiation is increased from December to March (when it is most useful in passive solar heating strategies).

(fig.9)

(fig.10)

© (fig.12)

© (fig.11)

© (fig.13)

Lisa Germain, Matteo Persanti, Lorenzo Piras

Finally the drop-down menu MONTHLY DATA have a kind of summary of what has been said so far (fig.14).

Through these analyzes with Ecotect we inferred which passive strategies will be used in our building even before start making it. This is a good starting point for making functional choices focused on sustainability and energy saving.

Going to sum up, we found: 1. The passive strategies that our building should have are thermal mass and solar heating. Making use of these two strategies alone our building will consume 65% energy less.

2. The solar heating is provided by 24% of the glass surface (oriented correctly).

3. Better orientation for the main façade is 2.5 ° N; 4. To take advantage of natural ventilation in summer we have the openings to the west and south 5. To take advantage of natural ventilation in winter we have the openings to the east.

Š (fig.14)

Lisa Germain, Matteo Persanti, Lorenzo Piras

Parametric Masterplan A Masterplan base on a Computer Aided Tool

Lisa Germain, Matteo Persanti, Lorenzo Piras

Parametric Masterplan A Masterplan base on a Computer Aided Tool The strength of our proposal lies in it original conception. We are not designing a particular solution but we propose a system, adaptable to any site. This system solves the housing requests starting from the characteristics of the area: topography, climate, preexisting buildings, as well as the density and quality request.

To achieve this goal we developed a computer aided tool that generates automatically an urban guideline.

This tool we have developed needs just a few inputs to run: 1 - surface topography of the area 2 - longitude and latitude 3 - size of the buildings that needs to be placed 4 - area contours and of the previous buildings inside of it 5 - attactor points of higher quality houses 6 - attractor points of higher density zones Once you put this data, the code generates a layout, an urban guideline that takes into account a set of parameters that wouldn’t be impossible to manage simultaneously with that precision. The accuracy of the output is absolute: our urban proposal is the crude realization of this output, without processing it.

This choice has been made in order to show the full strength of the system in its entirety, as wouldn’t never happen in the reality. It is an explicit manifesto of the system rather than a tailored solution.

The basic modeling assumptions to design the code are suitable for housing project in Addis Ababa, so it is a system tailored to Ethiopia.

The modeling assumptions are the following: Connections There is the need to minimize the lines of water, sewage and electrical connections in order to have easy maintenance and minors dispersions (in Ethiopia there is a loss of water due to errors in the connections amounting to 30% !) a linear system with serving blocks (containing bathroom and kitchen) aligned to use the same line infrastructure for water and electricity The rainwater harvesting must take account of the torrential rains in summer and should be exploited as a source of non-po table water but at the same time we must ensure safety if the infrastructures, making them resistant to these huge flows of water our solution is to use the driveway as the main macro-rainwater collector and so we designed it as a giant rain pipe, placed on the simulated flow curve of the terrain The difficulty of maintenance makes primary the need to give durability to the new structures, or at least to ensure a construc tive system easy to maintain our proposal is to collect water and electricity in the same infrastructure and in order to make it easily maintainable we decided to raise it off the ground, creating an aqueduct, a permeable element that can also be used as a covered walkway, useful during the rain season

Urban Addis Ababa is a city with an exponential demographical growth. Composed 94% of slums, government's proposal is to replace them with new buildings more dense and healthy.

One of the sincerest social demands is that in the new settlements must have the same dense network of relationships of the slum, a unique feature that needs to be protected To keep an urban system coincident to the existing one the obvious choice was to maintain the proportions between open and built surfaces. Taking account improvement devices for the health situation of the slum our decision was to propose a diffused fabric with semi-private spaces fragmented throughout the area.

That urban tissue presents the social characteristic widely semi-private typical of the slum on a new construction intervention We propose individual homes that have only one apartment per floor instead of a more traditional aggregative solution as like condominiums

our choice to place the aqueduct on the same axis of the driveway optimizes space and reinforce the meaning of this infrastructure

Lisa Germain, Matteo Persanti, Lorenzo Piras

Parametric Masterplan A Masterplan base on a Computer Aided Tool Imput explanation

1

Topography of the area

Select a 3D model of the topographic surface of the area and put it on the surface selector of the code

‌ and of that surface will be calculated the optimal flow curve

2

Longitude and Latitude

3

Size of the buildings that needs to be placed

To define the angle of the linear system you have to manually set longitude and latitude

Setting the mazimum height of the buildings the code will also automatically calculate the minimum spacing that should have the buildings to do not have an overshadowing one to the other. It is made through the “sun elevation angle� of the specific location.

The lines that will be generated have the optimal warping and are divided into points that are the base points to place the geometry of the buildings

Lisa Germain, Matteo Persanti, Lorenzo Piras

Parametric Masterplan A Masterplan base on a Computer Aided Tool Imput explanation

4

Area contours and of the previous buildings inside of it

5

Attactor points of higher quality houses

… and the previous buildings contours

As in the topographic surface, here you can load the area contours

When you design at that scale you use to plan higher quality zones, here, when you set the “attactor points”, the code interpolate the distance between them subdividing in quality areas your building site.

6

Associating to certain distances the typologies of the houses, it is displaced a visual subdivision of the “quality zones”...

Attractor points of higher density zones

Same thing can be done with the “density attractor points”. Those, differently from the “quality attractor points”, interpolate the distances between the points to have different values of height of the buildings according to the distance from those points.

The result of that is the extrusion of the buildings in plan, with a 3D oveview of your code!

This shapes are fundamentals to determine the edges in which must be generated the masterplan (our “domain”) and where the buildings cannot be placed by the code

… and so it places the buildings on the base points previously generated.

Water system design

Using the same lines in which the buildings have been placed, the code automatically generates the water system drawing, connecting it with all the serving blocks inside every house.

Final output of the code Once the code runs, the drawing can be exported in dwg and thus be easily modified. A final section of the code is able to calculate the overall cost of the design (to do that you must set the cost data relating to each typology of house), the percentage of built-up area , the number of inhabitants settled and the number of units generated.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Lisa Germain, Matteo Persanti, Lorenzo Piras

Unit Design Topics From the analysis of the housing types in the area of Teklehaimanot, and through the inspection of the same, we decided to base our concept of housing on a number of points that had as its final objective the following topics: - Improve absolutely the use of basis services, providing each house with a kitchen and a private bathroom; - Characterize the construction through building systems that keep a certain tradition with the local building knowledge using local materi als, but at the same time introduce new construction techniques that implement considerably the living standards; - Offer to the inhabitants different solutions, that have a definite set ting in terms of functionality and enjoyment but at the same time they can have a certain internal flexibility depending on the number of inhabitants; -Try to maintain the condition of social life and community present today at Teklehaimanot, and unite it with the new standards imposed by the government with the creation of the condominiums, in which unfortunately it has been somehow deleted.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Concept Our concept start from the introduction inside the housing typology of a module 3 m x 3 m large that collects all the basic services, essentials for the working of the house, around which subsequently develop all the other environments, this both for constructive features than compositional flexibility.

So the core is the area that contains the services, kitchen and bathroom, and also the point where convey the pipes of water and wastewater.

For all types developed, we decided to maintain the essential structure, so walls and environments are minimal; in fact this system has been designed in order to have a fast construction.

Thanks to the modularity provided by the type of building, each typology can be broken down further by the inhabitants themselves, depending on their needs and social condition.

Starting with the simplest arrangement, it is represented by the core, a sleeping area and a living area (typology E).

The living room area is the main shared enclosed space of the house, where most of the activities of daytime occure. It is also meant to be a space of transition between the outside and the inside.

An alternative to this first solution is given by the inclusion of additional space that makes possible to obtain an independent kitchen, and a corresponding extension of the living area; in this way it can accommodate a possible new space that can be allocated later. (typology D) The third type can be considered an evolution of the first, to which are added two other environments (typology C) that can be used as bedrooms. The central zone is made now by a space where take place the major activities of the house.

The L shape allows the creation on the ground floors of a garden space or a courtyard that can be private or shared with the neighborhood.

The two largest typologies are always based on the addition or extension of different environments, always respecting a rigorous modularity given both to facilitate a subsequent and further implementation and also to make the simplest possible way of construction.

Both are characterized by the inclusion of the lodges, to allow also the upper floors to have an habitable outdoor space for the inhabitants. (typology B and A)

Typology E

Typology C

Typology D

Typology B

Typology A Lisa Germain, Matteo Persanti, Lorenzo Piras

Building typology A number of inhabitants number stories

7

number of houses per stories

1 2 3

0 10 17

total houses percentage of houses

71 19,6 %

m² per house 63 total m² of each typology inhabitants per cathegories

4473 497

0

0.5

1

2

5m

Lisa Germain, Matteo Persanti, Lorenzo Piras

Building typology B number of inhabitants number stories

9

number of houses per stories

1 2 3

0 22 15

total houses percentage of houses

89 24,6 %

m² per house 74 total m² of each typology inhabitants per cathegories

6586 801

0

0.5

1

2

5m

Lisa Germain, Matteo Persanti, Lorenzo Piras

Building typology C number of inhabitants number stories

8

number of houses per stories

1 2 3

0 48 11

total houses percentage of houses

129 35,6 %

m² per house 68,5 total m² of each typology inhabitants per cathegories

8837 1032

0

0.5

1

2

5m

Lisa Germain, Matteo Persanti, Lorenzo Piras

Building typology D number of inhabitants number stories

5

number of houses per stories

1 2 3

0 17 2

total houses percentage of houses

40 11,6 %

m² per house 54 total m² of each typology inhabitants per cathegories

2160 200

0

0.5

1

2

5m

Lisa Germain, Matteo Persanti, Lorenzo Piras

Building typology E number of inhabitants number stories

4

number of houses per stories

1 2 3

2 14 1

total houses percentage of houses

33 9,1 %

m² per house 43 total m² of each typology inhabitants per cathegories

1419 132

0

0.5

1

2

5m

Lisa Germain, Matteo Persanti, Lorenzo Piras

Material Report Eucalyptus Drive to Entoto Mountain at the north of Addis or through the countryside, or look at the scaffolding on construction sites, or the building materials for simple homes, the prevalence and importance of eucalyptus in Ethiopia becomes quickly evident.

In about 1894 Emporer Menelik ordered the construction of a new capital for Ethiopia in Addis Ababa. There was a great need for timber for constructing this new city and Menelik endorsed the introduction of eucalyptus to Ethiopia from Australia at that time. Menelik encouraged its planting around Addis because of the massive deforestation that had taken place around the city for firewood and timber. Many plantations sprung up around the city and this spread to other areas throughout the country. It is a tree that adapts to a variety of environments.

One of the great advantages of the eucalyptus is that it is fast growing, requiring little attention and when cut down it grows up again from the roots; it can be harvested at least every ten years. It is intriguing to drive through the city or countryside and see large blocks of trees cut down that are regrowing.

Many have thought it ideal in watershed rehabilitation projects because it grows so quickly and can take root in eroding soil. Eucalyptus not only grows quickly it also grows very straight with few large branches.

This makes it ideal for timber for homes and for the ever-present scaffolding around the city with so much construction happening.

Another story on the evidence of eucalyptus is seen on the drive up to Entoto Mountain (which at 3048 m is 610 m higher than the rest of Addis). Its hundreds or thousands of acres are covered in eucalyptus and the cutting is government controlled. The need for firewood for families could put pressure on this land – acres of firewood in sight but not usable by the general population.

The prevalence of eucalyptus is seen every day as people go about their daily lives – firewood, timber for housing, scaffolding, carrying wood by hand or by truck ….. it is ever-present and ever-useful in the lives of people throughout Ethiopia.

© Eucalyptus trees and branches for sale

© Eucalyptus growing in gullies at watershed rehabilitation sites to prevent further erosion © Regrowth of cut eucalyptus trees

© Eucalyptus forests surround Addis Ababa to the north

© Tall, straight eucalyptus trees used in scaffolding (particular)

© Eucalyptus growing in gullies at watershed rehabilitation sites to prevent further erosion

© Tall, straight eucalyptus trees used in scaffolding

© Women wood carriers on Entoto mountain

Lisa Germain, Matteo Persanti, Lorenzo Piras

CSSB – Cement Stabilizied Soil Blocks The CSSB can give an impression of being a high quality construction material although being based on simple production methods. The blocks are suitable for the population with a low income and the resulting building costs may be cut down significantly if the blocks are manually produced. Different types of blocks are available. Some block types are mason together by lime mortar while some types are directly interlocking with no need for mortar in between.

Components A CSSB is a building block made from soil, water and cement; working as a stabiliser, mixed and compressed in a pressing machine.

Components, Mixture & Manufacturing process

Soil Soil is the main component that the CSSB consist of. There are soil of different qualities and disposition, depending on where it comes from and it is important that the soil has the right composition before being mixed with the cement and water. Before producing CSSB, the soil must be tested to determine if it is suitable for the CSSB-production.

The ideal soil for the CSSB contain: 50-75 % of coarse sand and fine gravel, 20-40 % of silt and fine sand 5-10 % clay Pure sand may be added to the soil to obtain the right proportions of the soil but should be avoided due to the costs of purchasing sand and the transportation costs. The finer fractions of the soil such as the clay and silt contribute to the fresh block not falling apart while the sand and gravel reacts with the cement to stabilise the cured and dry block.

Soil containing humus should not be used since it opposes the cement and it is therefore important not to use the topsoil (30-40 cm). The pH level is also of important factor; soil having a pH level below 4.5 or over 10 should be avoided as well as soils containing more than 2 % of sodium and potassium salts.

The main component in CSSB is one of the most available building materials, used for centuries throughout the world: soil. The blocks also consist of water and cement; working as a stabiliser, mixed and compressed in a pressing machine. The method is very suitable for the population with a low income if they are manually produced and the production process is relatively easy to learn. There are however essential processes in the production which highly affect the quality of the blocks and require consideration. Choosing the right soil for the production is important and the soil need to be pulverized and screened before being mixed with the other components. The mixing is also essential and the blocks need to be pressed immediately after being wet-mixed. The blocks also need to be cured for approximately 28 days before being used in production.

Cement The cement works as a stabiliser and prevents the blocks from being decomposed when in contact with water. By adding cement, the blocks will have further improved durability, strength and volume stability due to the chemical reactions taking place between the cement and the soil.

The effects will be in proportion to the cement quantity and the strengths of the blocks will generally increase linearly with the cement.

The effects will be in proportion to the cement quantity and the strengths of the blocks will generally increase linearly with the cement content, but at different rates for different soils. There is no need of adding more cement than needed for the purpose of the soil blocks due to the high costs of cement. The recommended cement rate is normally at a rate of 4-10 % (weight) depending on the type of soil.

Advantages/ Disadvantages •Poor water resistance. The main disadvantage with soil based construction materials is its poor ability to resist water. This can however in most cases be overcome by simple solutions and good workmanship.

•Brittleness. Another disadvantage is the materials’ brittleness as regards seismological issues. This can be overcome with further research in simple preventive solutions and by accuracy in performance.

•Low in tensile strength. The tensile strength is poor but it is not a big problem since constructional solutions allow for such materials to be used.

•Poor resistance to abrasion. The resistance to abrasion is poor; it requires maintenance and protection from animals.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Water Soil contains pores filled with air and water and these spaces will be reduced during compaction. By adding more water to the mixture the grains will be lubricated and air voids will be replaced making it easier for the grains to slide past one another. Water is also necessary in the hydration process of the cement. It will together with the silt and clay make the fresh block not fall apart after being pressed. The amount of water varies depending on the dryness of the soil.

Production process Grinding and pulverisation The soil must initially be pulverised to obtain uniform mixing of the components. Lumps and larger pieces of soil are broken up usually by being pressed between two surfaces. Grains with a homogeny structure such as stones and gravel must be left unbroken and separated from the soil. The grains having a composite structure such as clay must be broken up so that at least 50% of the grains are less than 5 mm in diameter. There are different types of machines for this purpose. It is on the other hand easy to obtain a uniform pulverised soil by manual pounding without acquiring expensive machinery for this purpose. The easiest way of preparing the right soil mixture is by moulding it with the feet or using animal power. The soil will be easily crushed and pulverised when being moist. It is however very important that the soil is properly dried before being mixed. Wet or moist soil will react sooner with the cement before being properly mixed, resulting in inferior qualities of the pressed blocks. It can be used for other purposes or can be further grinded and pulverised and once again be screened. In most cases grains up to 10 mm are passed and obtained during this process.

Screening This is a necessary part of the process and is essential when the pulverisation has been incomplete and there are large particles in the soil. To separate them from the soil, a fixed screen is set up at an angle or is suspended. Although there are mechanically available machines for this job, the operation is easily carried out manually. Raw soil is thrown with a shovel at the top of the fixed screen. The screened soil is then loaded onto a wheelbarrow and is ready to be mixed with the other components while the larger unscreened material is rejected. It can be used for other purposes or can be further grinded and pulverised and once again be screened. In most cases grains up to 10 mm are passed and obtained during this process.

Mixing Proper mixing ensures the succeeding quality of the product and of the structure itself. It also guarantees that the blocks are built economically in the case that it optimises the proportions of the components. Mixing dry and moist materials will create certain problems especially in the case when a stabiliser such as cement is included. The dry soil and cement should be mixed properly until it is of a consistent colour and no dissimilar layers can be seen in the mixture. The amount of water is added afterwards by progressive sprinkling of small amounts. Too much water will reduce the strength of the blocks hence it is important to use the right amount. Right amount of water has been added to the mixture when a sample, that being squeezed in the hand, stick together without any water seeping out. The planning of the mixing is important; mixing of soil is very different to the mixing of concrete, because while concrete is not cohesive, soil is. There is a risk of formatting of lumps and crumbs that could reduce the strength of the blocks. The most economical way to perform this operation is by manual mixing. This is carried out usually by one or two individuals using a shovel, mixing the amounts on a hard surface.

The mixture must be pressed without delay after water has been added to the soil and cement mixture due to the danger that the cement may set prematurely.

Pressing A pressing machine is loaded with the right amount of the wet mixture of soil, cement and water. There are currently different kinds of presses available on the market both manual and mechanical. The best-known press worldwide is the manual Cinva-Ram, developed in Colombia.

The advantages of these types of presses are that they are light, manually operated, low-cost, have a simple sturdiness and are easily produced and prepared. The disadvantages are that they only have a single moulding module, are low pressured and have a low output compared to the mechanical presses. The average output is approximately 150-300 blocks per day. The press will compress the mixture, shaping it into a block. Different shapes such as angular or interlocking blocks can be produced by changing the form of the pressing mould. The pressed blocks need to be transported to a storage room, preferably at a close distance to the pressing machine.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Curing It is important to protect the pressed blocks from rain and sunlight. The curing shall therefore take place in a rain protected storage space for at least four weeks. The blocks can be carried to the curing area by hand. It is best to use a flat board to lift and carry the blocks because this prevents any damage to the blocks. The blocks need to be cured in shade on a clean and levelled area and should be stacked no more than 5 blocks high until they are fully cured. Spaces should be left for air to pass between the blocks.

Curing is the process of the blocks getting stronger and setting hard and this process is divided into two parts; wet and dry curing. During the first 7 days the blocks should be watered, preferably sprinkled once per day and covered with plastic sheeting. If the blocks are not kept moist, there is a possibility that they will crack or be weakened due to the shrinkage of the clay in the soil. After 7 days the plastic sheet should be removed and the blocks will start their dry curing for at least 21 more days before being used. The curing phase is essential for the blocks future strength and durability and should be carefully executed. A sample of the blocks should be pressure tested before being used to ensure that they meet the criteria regarding their strength

Lisa Germain, Matteo Persanti, Lorenzo Piras

Eucalyptus Plywood

Manufacturing Process

Plywood is a sheet material manufactured from thin layers or „plies“ of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which includes medium-density fibreboard (MDF) and particle board (chipboard).

All plywoods bind resin and wood fiber sheets (cellulose cells are long, strong and narrow) to form a composite material. This alternation of the grain is calledcross-graining and has several important benefits: it reduces the tendency of wood to split when nailed at the edges; it reduces expansion and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across all directions. There are usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite parts, it is very hard to bend it perpendicular to the grain direction of the surface ply.

Ward blocking: The logs of wood are removed and cut according to the size required. This process is known as ward blocking.

Cooking: This process is called so because the wood cut is exposed to a pre-set temperature of about 60-80 degrees.

It might take 12 hours or so for the cooking process to be completed.

This is done to remove starch and also to eliminate microscopic organisms present in wood. Because if the organisms are not killed, then, they might attack the resultant ply and thus damage it.

Peeling: It is just what the name suggests. The log after being cooked, is peeled as per the thickness required. It is done with the help of a peeling machine.

Reeling: Now the wood can be called veneer. It is subsequently reeled.

Clipping: The veneer is clipped as per the dimensions required.

Drying: The veneer is now dried at a certain temperature. The aim of this step is remove all moisture content and also to kill any residue microorganisms. This step is very important because any veneer containing moisture is unsuitable to make a ply.

Resin: or gluing process. This is also an important part of the manufacturing process, because correct gluing is the secret to a strong ply.

Most companies prefer to produce resin in-house to ensure maximum quality. The veneers are glued and perfected so as to ensure strength and dimensional stability.

Testing: The plywood just made is tested in laboratories for any defects.

Pressing: There are usually two press methods, one is the pre press method and second, the hot press. The pre press process helps to expand and stabilize each layer to ensure that the product is warp free.

The hot press process is to make certain that the ply is of uniform density at all levels and points. After undergoing both these steps, the ply is allowed to cool for 24 hours.

Cutting and trimming: It is essential that the ply has dimensional accuracy. That is why this process is done very carefully.

Sanding: This step provides a even surface to the ply Inspection and despatch: The last step is to check for the quality of plywood and then the plies are despatched to various locations as per the orders received. There are many types of plywood available, depending on the thickness, the kind of wood the ply is made from and also quality.

Lisa Germain, Matteo Persanti, Lorenzo Piras

© Soaking of logs

© Debarking

© Cutting

© Peeling / Rotary cutting of veener

© Sorting and Bonding

© Pressing

Lisa Germain, Matteo Persanti, Lorenzo Piras

BUILDING PROCESS Laying out a building 1. All vegetation and organic top soil should be removed. Leave enough space around the limits of the house for working area and to prepare the soil for the walls. Collect the top soil at a special place to keep it clean so you can use it again after the building is completed. Do the same with plants if necessary.

2. Install Batter boards 0,8 m high and 1,5 m long at the corners an partition walls 1,2 m away from the proposed outside wall of the house.

3. Check that the taut lines are at the right angles. This can be done with the aid of a readymade wooden triangle or a string or wire triangle whose sides are proportioned 3:4:5. Rule: if the buildings or room corners are at right angles, then the diagonals will be equal length.

4. To insure that the foundations and later walls with the openings and the ceiling and roof are at the right and level, mark a high point on an existing house or tree where it won’t be lost. Using a water hose (not quite filled) as a water level. This point can then be marked on posts pounded in close to the batter boards.

Foundation 1. The limits of the foundations are plumbed from the batter boards and marked with a spade or pickaxe.

2. The trench for the foundation is dug out.

3. If the ground slopes, the subsurface of the trench is dug in steps, each step being horizontal.

4. If the soil is unstable the foundation has to be shuttered. Allow enough working space on both sides of the foundation 5. The excavation material is stored between the foundation ditches and serves as backfill later.

6. Check level and height with hose level comparing to fixed height marking or stretch strings between markings on posts and measure from this. Together with the measuring of the foundation level. Measure the slope and course of drainage.

7. Filling concrete in foundation ditch, in sloped ground make sure surface is horizontal, if necessary form steps.

8. The plinth should be at least 50 cm above the ground.

9. The material for the plinth is poured in the shuttering, e.g a mixture of rubble stones and lime or concrete mortar.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Foundation and Ground Floor For the ground floor of each typology, we decided to use CSSB – Cement Stabilizied Soil Blocks. These are assembled onto walls using standard bricklaying and masonry techniques. The „mortar“ may be a simple slurry made of the same soil/clay mix without aggregate, spread or brushed very thinly between the blocks for bonding. Cement mortar may also be used for high strength.

CSSB walls utilize an easily handled small units do not require formwork, because CSSB is a modular material, all major dimensions are based on the module of one block, 40 x 20 x 20 cm.

Construction method is simple. Less skilled labor is required; wall construction can be done with unskilled labor encouraging self-sufficiency and community involvement. If the blocks are stabilized with cement, fly ash, lime, rice husks or they can be used as bricks and assembled using standard masonry techniques of brick-laying or even in some cases dry stacked further reducing total construction costs.

Completed walls require either a reinforced bond beam or a ring beam on top or between floors (8‘)and if the blocks are not stabilized, a plaster finish, usually stucco wire/stucco cement and or lime plaster. Stabilized blocks create a brick wall that if properly stabilized can be left exposed with no outer plaster finish. There are also countless local materials that can be used for natural plasters and tuck pointing techniques that help to reduce the total cost of construction.

Standards for foundations are similar to those for brick walls. A CSSB wall is heavy. Footings must be at least 10 inches thick, with a minimum width that is 33 percent greater than the wall width. If a stem wall is used, it shall extend to an elevation not less than eight inches (203 mm) above the exterior finish grade. Rubble-filled foundation trench designs with a reinforced concrete grade beam above are allowed to support CSSB construction. For openings like doors and window, we use the same modules created for the upper floors in platform frame.

The top of the CSSB wall must be prepared to receive, support, and anchor the platform frame and wood joist floor systems of the superstructure. For this we use reinforcement bars inserted into the holes of the blocks. For the entire height of the wall the hole will be filled with cement mortar, and the reinforcing bar will exit for the height needed for the anchor.

© Example of a Foundation reinforced concrete strip in one of our Typologies

© Particolar of the Foundation reinforced concrete strip

© Openings on the ground floor made by plywood modules

© Classical Built method of a low cost foundation

© Reinforcedment bars inserted into the holes of the blocks

Lisa Germain, Matteo Persanti, Lorenzo Piras

Foundation Cost per Typology

Typology A Reinforced concrete strip Foundation Formwork blocks Gravel Lean Concrete Reinforced concrete slab Wooden Strips Wood Flooring (Plywood)

Typology B Reinforced concrete strip Foundation Formwork blocks Gravel Lean Concrete Reinforced concrete slab Wooden Strips Wood Floring (Plywood)

Typology C Reinforced concrete strip Foundation Formwork blocks Gravel Lean Concrete Reinforced concrete slab Wooden Strips Wood Floring (Plywood)

Thickness (m) 0,80 0,80 0,25 0,05 0,15 0,04 0,02

m

m2

m3

cost(birr)/

cost (€)/

tot (birr)

tot (€)

138,80 129,00 -

47,20 111,04 52,28 52,28 52,28 87,28

37,76 13,07 2,61 7,84 -

2.058,56 51,75 391,00 2.058,56 2.058,56 6,00 297,00

82,34 2,07 15,64 82,34 82,34 0,24 11,88

77.731,23 5.746,32 5.110,37 5.381,08 16.143,23 774,00 25.922,16 136.808,38

3.109,25 229,85 204,41 215,24 645,73 30,96 1.036,89 5.472,34

Thickness (m)

m

m2

m3

cost(birr)/

cost (€)/

tot (birr)

tot (€)

0,80 0,80 0,25 0,05 0,15 0,04 0,02

137,20 131,20 -

46,12 109,76 53,56 53,56 53,56 84,04

36,90 13,39 2,68 8,03 -

2.058,56 51,75 391,00 2.058,56 2.058,56 6,00 297,00

82,34 2,07 15,64 82,34 82,34 0,24 11,88

75.952,63 5.680,08 5.235,49 5.512,82 16.538,47 787,20 24.959,88 134.666,57

3.038,11 227,20 209,42 220,51 661,54 31,49 998,40 5.386,66

Thickness (m)

m

m2

m3

cost(birr)/

cost (€)/

tot (birr)

tot (€)

0,80 0,80 0,25 0,05 0,15 0,04 0,02

115,30 111,20 -

40,96 92,24 41,56 41,56 41,56 69,92

32,77 10,39 2,08 6,23 -

2.058,56 51,75 391,00 2.058,56 2.058,56 6,00 297,00

82,34 2,07 15,64 82,34 82,34 0,24 11,88

67.454,89 4.773,42 4.062,49 4.277,69 12.833,06 667,20 20.766,24 114.834,99

2.698,20 190,94 162,50 171,11 513,32 26,69 830,65 4.593,40

Typology D Reinforced concrete strip Foundation Formwork blocks Gravel Lean Concrete Reinforced concrete slab Wooden Strips Wood Floring (Plywood)

Typology E Reinforced concrete strip Foundation Formwork blocks Gravel Lean Concrete Reinforced concrete slab Wooden Strips Wood Floring (Plywood)

Thickness (m) 0,80 0,80 0,25 0,05 0,15 0,04 0,02

Thickness (m) 0,80 0,80 0,25 0,05 0,15 0,04 0,02

m

m22

m33

cost(birr)/

cost (€)/

tot (birr)

tot (€)

96,40 84,20 -

31,96 77,12 34,00 34,00 34,00 56,64

25,57 8,50 1,70 5,10 -

2.058,56 51,75 391,00 2.058,56 2.058,56 6,00 297,00

82,34 2,07 15,64 82,34 82,34 0,24 11,88

52.633,26 3.990,96 3.323,50 3.499,55 10.498,66 505,20 16.822,08 91.273,21

2.105,33 159,64 132,94 139,98 419,95 20,21 672,88 3.650,93

m

m22

m33

cost(birr)/

cost (€)/

tot (birr)

tot (€)

82,00 66,20 -

27,64 65,60 25,36 25,36 25,36 43,08

22,11 6,34 1,27 3,80 -

2.058,56 51,75 391,00 2.058,56 2.058,56 6,00 297,00

82,34 2,07 15,64 82,34 82,34 0,24 11,88

45.518,88 3.394,80 2.478,94 2.610,25 7.830,76 397,20 12.794,76

1.820,76 135,79 99,16 104,41 313,23 15,89 511,79

75.025,60

3.001,02

Lisa Germain, Matteo Persanti, Lorenzo Piras

Ground Floor Cost per Typology Typology A CSSB Wall Module C Module E Module G (e) Module G (i) Module H(e) Module H (i) Module I Module L

Typology B CSSB Wall Module C Module E Module G (e) Module G (i) Module H(e) Module H (i) Module I Module L

Typology C CSSB Wall Module C Module I Module G(i) Module H (i) Module I Module L

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

14 2 12 10 3 3 1 1

51,80 -

128,46 -

51,75 1.860,21 2.297,44 444,01 424,89 307,01 294,25 2.345,14 2.106,00

2,07 74,41 91,90 17,76 17,00 12,28 11,77 93,81 84,24

6.648,01 26.042,94 4.594,89 5.328,07 4.248,90 921,03 882,74 2.345,14 2.106,00 53.117,72

265,92 1.041,72 183,80 213,12 169,96 36,84 35,31 93,81 84,24 2.124,71

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

16 1 6 9 2 1 1 1

52,20 -

129,46 -

51,75 1.860,21 2.297,44 444,01 424,89 307,01 294,25 2.345,14 2.106,00

2,07 74,41 91,90 17,76 17,00 12,28 11,77 93,81 84,24

6.699,35 29.763,36 2.297,44 2.664,03 3.824,01 614,02 294,25 2.345,14 2.106,00 50.607,60

267,97 1.190,53 91,90 106,56 152,96 24,56 11,77 93,81 84,24 2.024,30

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

20 1 9 2 1 1

47,20 -

117,06 -

51,75 1.860,21 574,02 424,89 294,33 2.345,14 2.106,00

2,07 74,41 22,96 17,00 11,77 93,81 84,24

6.057,65 37.204,20 574,02 3.824,01 588,66 2.345,14 2.106,00 52.699,67

242,31 1.488,17 22,96 152,96 23,55 93,81 84,24 2.107,99

Typology D CSSB Wall Module C Module I Module G(i) Module H (i) Module I Module L

Typology E CSSB Wall Module C Module I Module G(i) Module H (i) Module I Module L

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

14 1 6 1 1 1

40,50 -

100,44 -

51,75 1.860,21 574,02 424,89 294,25 2.345,14 2.106,00

2,07 74,41 22,96 17,00 11,77 93,81 84,24

5.197,77 26.042,94 574,02 2.549,34 294,25 2.345,14 2.106,00 39.109,46

207,91 1.041,72 22,96 101,97 11,77 93,81 84,24 1.564,38

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

12 1 5 2 1 1

34,80 -

86,30 -

51,75 1.860,21 574,02 424,89 294,25 2.345,14 2.106,00

2,07 74,41 22,96 17,00 11,77 93,81 84,24

4.466,23 22.322,52 574,02 2.124,45 588,50 2.345,14 2.106,00 34.526,86

178,65 892,90 22,96 84,98 23,54 93,81 84,24 1.381,07

Lisa Germain, Matteo Persanti, Lorenzo Piras

Platform Frame The structure of the floors subsequent to the first is formed by a platform frame system consists of various modules prefabricated made by structural plywood in Eucalyptus.

Platform framing is a light wood frame having studs only one story high, regardless of the stories built, each story resting on the top plates of the stories below or on the sill plates of the foundation wall.

Stud walls, or modules, are adaptable to off-site fabrication as panels or to tilt - up construction. Although vertical shrinkage is greater than in ballon frame, it is equalized between floors.

Each module will have its characteristics depending on the function and location in the building system. This allows to optimize the construction and the efficiency of each individual element.

The modules that will form the outer walls, for example, will have within them pumice powder bags which will act as thermal inertia. We chose to use this material because pumice has good thermal and sound insulation properties. It has very low permeability and adequate compressive strength and modules of elasticity and hence can be used for stucco and plaster aggregate. It can be an opportunity; in fact pumice is widespread in Ethiopia, but it is utilized only in limited areas for the purpose of cement and block production.

The structure of each module will then be closed on both sides by a plywood paneling, and for the external facade will use the corrugated iron sheet, very flexible material designed to protect the entire structure from rain.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Platform Frame System

G (i) H (e) H (i) I L

10 3 3 1 1

424,89 307,01 294,25 2.345,14 2.106,00

17,00 12,28 11,77 93,81 84,24

4.248,90 921,03 882,74 2.345,14 2.106,00 189.346,31

169,96 36,84 35,31 93,81 84,24 9.613,03

Typology B Module A(e) A(i) B (e) B (i) C D(e) D(i) E F (e) F (i) G (e) G (i) H (e) H (i) I L

n° 31 19 21 18 16 1 1 1 18 10 6 9 1 2 1 1

cost(birr)/ 1.888,12 1.718,82 1.441,13 1.329,39 1.860,21 994,14 939,81 2.297,44 1.814,86 1.470,64 444,01 424,89 307,01 294,25 2.345,14 2.106,00

cost (€)/ 75,52 68,75 57,65 53,18 74,41 39,77 37,59 91,90 72,59 58,83 17,76 17,00 12,28 11,77 93,81 84,24

tot (birr) 58.531,87 32.657,50 30.263,79 23.929,08 29.763,36 994,14 939,81 2.297,44 32.667,55 14.706,40 2.664,03 3.824,01 307,01 588,50 2.345,14 2.106,00 238.585,63

tot (€) 2.341,27 1.306,30 1.210,55 957,16 1.190,53 39,77 37,59 91,90 1.306,70 588,26 106,56 152,96 12,28 23,54 93,81 84,24 9.543,43

Cost per Typology Typology A Typology C Module A(e) Module A(e) A(i) BA(i) (e) (e) B (i) CB (i) C D(e) D(e) D(i) ED(i) FE (e) F (i) (e) F (i) G (e) (e) G (i) G (e) (i) H H (i) (e) IH (i) LI L

n° n° 27 25 22 20 19 20 18 14 20 1 1 21 19 17 9 10 12 10 39 312 1 1

cost(birr)/ cost(birr)/ 1.888,12 1.888,12 1.718,82 1.718,82 1.441,13 1.441,13 1.329,39 1.329,39 1.860,21 1.860,21 994,14 994,14 939,81 939,81 2.297,44 1.814,86 1.814,86 1.470,64 1.470,64 444,01 424,89 424,89 307,01 294,25 294,25 2.345,14 2.106,00 2.345,14 2.106,00

cost (€)/ cost (€)/ 75,52 75,52 68,75 68,75 57,65 57,65 53,18 53,18 74,41 74,41 39,77 39,77 37,59 37,59 91,90 72,59 72,59 58,83 58,83 17,76 17,00 17,00 12,28 11,77 11,77 93,81 84,24 93,81 84,24

tot (birr) tot (birr) 50.979,37 47.203,12 37.813,95 34.376,32 28.822,66 27.381,52 26.587,87 23.929,08 26.042,94 37.204,20 994,14 994,14 939,81 939,81 4.594,89 34.482,42 30.852,69 13.235,76 14.706,40 5.328,07 4.248,90 3.824,01 921,03 882,74 588,50 2.345,14 2.106,00 2.345,14 189.346,31 2.106,00 226.450,93

tot (€) tot (€) 2.039,17 1.888,12 1.512,56 1.375,05 1.152,91 1.095,26 1.063,51 957,16 1.041,72 1.488,17 39,77 39,77 37,59 37,59 183,80 1.379,30 1.234,11 529,43 588,26 213,12 169,96 152,96 36,84 35,31 23,54 93,81 84,24 93,81 9.613,03 84,24 9.058,04

Typology B Module Typology D A(e) Module A(i) A(e) BA(i) (e) B (i) (e) CB (i) D(e) C D(i) D(e) ED(i) FE (e) F (i) (e) G (e) F (i) G G (i) (e) H G (e) (i) H H (i) (e) IH (i) LI

n° 31 n° 19 23 21 14 18 16 14 1 14 1 1 18 10 16 66 916 211 11

cost(birr)/ 1.888,12 cost(birr)/ 1.718,82 1.888,12 1.441,13 1.718,82 1.329,39 1.441,13 1.860,21 1.329,39 994,14 1.860,21 939,81 994,14 2.297,44 939,81 1.814,86 1.470,64 1.814,86 444,01 1.470,64 424,89 307,01 424,89 294,25 2.345,14 294,25 2.106,00 2.345,14

cost (€)/ 75,52 cost (€)/ 68,75 75,52 57,65 68,75 53,18 57,65 74,41 53,18 39,77 74,41 37,59 39,77 91,90 37,59 72,59 58,83 72,59 17,76 58,83 17,00 12,28 17,00 11,77 93,81 11,77 84,24 93,81

1

2.106,00

84,24

tot (birr) 58.531,87 tot (birr) 32.657,50 43.426,87 30.263,79 24.063,42 23.929,08 25.940,39 29.763,36 18.611,51 994,14 26.042,94 939,81 994,14 2.297,44 939,81 32.667,55 14.706,40 29.037,82 2.664,03 8.823,84 3.824,01 307,01 2.549,34 588,50 2.345,14 294,25 2.106,00 2.345,14 238.585,63 2.106,00

tot (€) 2.341,27 tot (€) 1.306,30 1.737,07 1.210,55 962,54 957,16 1.037,62 1.190,53 744,46 39,77 1.041,72 37,59 39,77 91,90 37,59 1.306,70 588,26 1.161,51 106,56 352,95 152,96 12,28 101,97 23,54 93,81 11,77 84,24 93,81 9.543,43 84,24

L

185.175,47

7.407,02

Typology E Module A(e) A(i) B (e) B (i) C D(e) D(i) E F (e) F (i) G (e) G (i) H (e) H (i) I L

n° 23 14 16 12 12 1 1 14 5 5 2 1 1

cost(birr)/ 1.888,12 1.718,82 1.441,13 1.329,39 1.860,21 994,14 939,81 1.814,86 1.470,64 424,89 294,25 2.345,14 2.106,00

cost (€)/ 75,52 68,75 57,65 53,18 74,41 39,77 37,59 72,59 58,83 17,00 11,77 93,81 84,24

tot (birr) 43.426,87 24.063,42 23.058,12 15.952,72 22.322,52 994,14 939,81 25.408,10 7.353,20 2.124,45 588,50 2.345,14 2.106,00 170.682,99

tot (€) 1.737,07 962,54 922,32 638,11 892,90 39,77 37,59 1.016,32 294,13 84,98 23,54 93,81 84,24 6.827,32

Typology C Module A(e) A(i) B (e) B (i) C D(e) D(i) E F (e) F (i) G (e) G (i) H (e) H (i) I L

n° 25 20 19 18 20 1 1 17 10 9 2 1 1

cost(birr)/ 1.888,12 1.718,82 1.441,13 1.329,39 1.860,21 994,14 939,81 1.814,86 1.470,64 424,89 294,25 2.345,14 2.106,00

cost (€)/ 75,52 68,75 57,65 53,18 74,41 39,77 37,59 72,59 58,83 17,00 11,77 93,81 84,24

tot (birr) 47.203,12 34.376,32 27.381,52 23.929,08 37.204,20 994,14 939,81 30.852,69 14.706,40 3.824,01 588,50 2.345,14 2.106,00 226.450,93

tot (€) 1.888,12 1.375,05 1.095,26 957,16 1.488,17 39,77 37,59 1.234,11 588,26 152,96 23,54 93,81 84,24 9.058,04

Typology D Module A(e) A(i) B (e) B (i) C D(e) D(i) E F (e) F (i) G (e) G (i) H (e) H (i) I L

n° 23 14 18 14 14 1 1 16 6 6 1 1 1

cost(birr)/ 1.888,12 1.718,82 1.441,13 1.329,39 1.860,21 994,14 939,81 1.814,86 1.470,64 424,89 294,25 2.345,14 2.106,00

cost (€)/ 75,52 68,75 57,65 53,18 74,41 39,77 37,59 72,59 58,83 17,00 11,77 93,81 84,24

tot (birr) 43.426,87 24.063,42 25.940,39 18.611,51 26.042,94 994,14 939,81 29.037,82 8.823,84 2.549,34 294,25 2.345,14 2.106,00 185.175,47

tot (€) 1.737,07 962,54 1.037,62 744,46 1.041,72 39,77 37,59 1.161,51 352,95 101,97 11,77 93,81 84,24 7.407,02

Lisa Germain, Matteo Persanti, Lorenzo Piras

Wood Joist Floor Wood joists floors are an essential subsystem of wood light-frame construction. The dimension lumber used for joists is easily worked an can be quick assembled on site with simple tools. Together with wood panel sheating or sub flooring, the wood joists form a level working platform for construction. If properly engineered, the result floor structure can serve as a structural diaphragm to transfer lateral loads to shear walls.

Joist are spaced 12”, 16” or 24” (305, 405 or 610 cm) o.c, depending on the magnitude of applied loads and spanning capability of the subflooring (1) Cavities can accommodate piping, wiring and thermal insulation (2).

Ceiling may be applied directly to joists, or be suspended to lower ceiling area or conceal mechanical runs perpendicular to joists (3).

Lisa Germain, Matteo Persanti, Lorenzo Piras

Wood Joist Floor Cost per Typology Typology A Lateral support Corr. Iron Sheet Double top plate Joists (3,06 cm) Joists (2,86 cm) Joists (2,4 cm) Panel subflooring Ceiling

Typology B Lateral support Corr. Iron Sheet Double top plate Joists (3,06 cm) Joists (2,86 cm) Joists (2,4 cm) Panel subflooring Ceiling

Typology C Lateral support Corr. Iron Sheet Double top plate Joists (3,06 cm) Joists (2,86 cm) Joists (2,46 cm) Joists (2,4 cm) Panel subflooring Ceiling

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

19 19 19 -

40,64 -

6,50 6,50 31,76 100,80 84,92

593,00 100,00 593,00 580,67 542,71 455,42 297,00 297,00

23,72 4,00 23,72 23,23 21,71 18,22 11,88 11,88

3.855,92 650,24 18.833,68 11.032,73 10.311,49 8.652,98 29.937,60 25.221,24 108.495,88

154,24 26,01 753,35 441,31 412,46 346,12 1.197,50 1.008,85

4.339,84

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

19 19 19 -

40,64 -

6,50 6,50 29,84 100,80 85,88

593,00 100,00 593,00 580,67 542,71 455,42 297,00 297,00

23,72 4,00 23,72 23,23 21,71 18,22 11,88 11,88

3.855,92 650,24 17.695,12 11.032,73 10.311,49 8.652,98 29.937,60 25.506,36 107.642,44

154,24 26,01 707,80 441,31 412,46 346,12 1.197,50 1.020,25

4.305,70

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

9 16 7 18 -

40,64 -

6,50 6,50 27,28 82,14 68,50

593,00 100,00 593,00 580,67 542,71 466,81 455,42 297,00 297,00

23,72 4,00 23,72 23,23 21,71 18,67 18,22 11,88 11,88

3.855,92 650,24 16.177,04 5.226,03 8.683,36 3.267,67 8.197,56 24.395,58 20.344,50 90.797,90

154,24 26,01 647,08 209,04 347,33 130,71 327,90 975,82 813,78

Typology D Typology Lateral supportD

n° n° -

ml ml 34,64

m2 m2 5,54

cost(birr)/ cost(birr)/ 593,00

cost (€)/ cost (€)/ 23,72

tot (birr) tot (birr) 3.286,64

tot (€) tot (€) 131,47

Lateral support Corr.

Iron Sheet Corr.

Iron Double topSheet plate Double top cm) plate Joists (2,86 (2,86 cm) Joists (2,46 Joists (2,46 cm) Panel subflooring Panel subflooring Ceiling

19 19 19 -

34,64 -

5,54 5,54 21,68 21,68 64,80 64,80 53,96 53,96

593,00 100,00 100,00 593,00 593,00 542,71 542,71 466,81 466,81 297,00 297,00 297,00

23,72 4,00 4,00 23,72 23,72 21,71 21,71 18,67 18,67 11,88 11,88 11,88

3.286,64 554,24 554,24 12.856,24 12.856,24 10.311,49 10.311,49 8.869,39 8.869,39 19.245,60 19.245,60 16.026,12 16.026,12 71.149,72 71.149,72

131,47 22,17 22,17 514,25 514,25 412,46 412,46 354,78 354,78 769,82 769,82 641,04 641,04 2.845,99

Ceiling

2

2.845,99

Typology E Typology Lateral supportE

n° n° -

ml ml 29,84

m m2 4,77

cost(birr)/ cost(birr)/ 593,00

cost (€)/ cost (€)/ 23,72

tot (birr) tot (birr) 2.831,22

tot (€) tot (€) 113,25

Lateral support Corr.

Iron Sheet Corr. Iron Double topSheet plate Double top cm) plate Joists (2,86 (2,86 cm) Joists (2,46 Joists (2,46 cm) Panel subflooring Panel subflooring Ceiling

15 15 15 -

29,84 -

4,77 4,77 18,08 18,08 51,84 51,84 42,44 42,44

593,00 100,00 100,00 593,00 593,00 542,71 542,71 466,81 466,81 297,00 297,00 297,00

23,72 4,00 4,00 23,72 23,72 21,71 21,71 18,67 18,67 11,88 11,88 11,88

2.831,22 477,44 477,44 10.721,44 10.721,44 8.140,65 8.140,65 7.002,15 7.002,15 15.396,48 15.396,48 12.604,68 12.604,68 57.174,06 57.174,06

113,25 19,10 19,10 428,86 428,86 325,63 325,63 280,09 280,09 615,86 615,86 504,19 504,19 2.286,96

Ceiling

2.286,96

3.631,92

Lisa Germain, Matteo Persanti, Lorenzo Piras

Corrugated Metal Roofing The roof consists of a final walk-on cover floor on which are based the pre-assembled metal trusses. The choice of metal is not random, as it is a easily available material, and it can be worked by the numerous metallurgical activities of the place. On the trusses will be mounted on the purlins and then the corrugated iron sheet, characteristic material widely used for roofing in Ethiopia. It is thus to create a useful intermediate space, suitable both for natural ventilation, both for the arrangement of the water tanks that will serve the building.

This wood joists floor, differently from the intermediate one, will have an internal insulation made of fiber slabs soil, very simple elements produced by reusing the simple soil of the excavations for the foundations of the building.

The metal trusses that will supported the corrugated iron sheet will have an overhang of one metet at least , to counter the heavy rains that characterize Addis Ababa during the summer.

Lisa Germain, Matteo Persanti, Lorenzo Piras

FIBER SOIL SLABS FOR CEILING AND ROOF COVERING Production procedure

cm

1. To produce fiber soil slabs, first you need a soil and fiber mixture and round peeled of at least 3 cm ø. These steaks have the length of the slabs. They are first soaked in water.

30

1.

8 cm

70 c m

Batten 2/6 cm for support Batten 2/6 cm for support

2.

2. The sticks were smeared with mud or dipped in mud slush.

Section with sticks pressed down to the recess woods

Section with recess woods

3.

3. About 4 cm of the fiber soil mixture is kneaded into the slab form.

4.

4. Two or three sticks, prepared as above, are pushed into the mixture so that each stick touches the batten 1 at both ends.

5.

5. The form is filled with the fiber soil mixture.

6.

6. The mixture is smoothed with a straight board in sawing movements

Lisa Germain, Matteo Persanti, Lorenzo Piras

FIBER SOIL SLABS FOR CEILING AND ROOF COVERING Production procedure 7.

7. The Form is then given a horizontal turn to free it from the working plate. Then turn it over and free slab with a quick jerk. Let it dry in a shaded place like adobe.

8.

8. The surface is brushed repeatedly with mud slush to close the cracks.

9.

9. The fiber soils slabs (70 x 30 x 8) cm, weight 25 kg are laid on the rafters beginning at the eaves and continuing upwards to the ridge. The lowest slab of each row is held by the the gutter or a special board nailed to the rafters. The rest of the slab are held by small wooden blocks. Recesses for these blocks are provided in the form.

10.

10. All ends of the reinforcement sticks must have support on the rafters. If not fill the gap with wedges. The ridge is closed with sticks and covered with moist fiber soil mixture. The slabs can’t bear too much load, therefore use ladders to spread your weight when you are working on the roof.

11.

11. The joints between the slabs are filled with mud mortar and the surface is smoothed with a trowel.

Then the whole surface is moistened and covered with 2 cm fiber soil mortar. If available mixed with sulphur or lime. Finally the roof may be covered with corrugated sheets laid on spacers.

Lisa Germain, Matteo Persanti, Lorenzo Piras

Metal Truss Typology C Purlins Long Wooden Truss Corrugated Iron Sheet Long Metal Truss Short Wooden Truss Short Metal Truss Purlins Typology C

Corrugated Metal Roofing Cost per Typology

n°

ml

m2

cost(birr)/

cost (€)/

tot (birr)

tot (€)

Wooden Truss Metal Truss Purlins Corrugated Iron Sheet Typology A

4 4 n°

42,60 42,60 249,60 ml

145,60 m2

69,00 120,00 69,00 100,00 cost(birr)/

2,76 4,80 2,76 4,00 cost (€)/

11.757,60 20.448,00 17.222,40 14.560,00 tot (birr) 63.988,00

470,30 817,92 688,90 582,40 tot (€) 1.741,60

Wooden Truss Metal Truss Typology B Purlins Wooden Truss Corrugated Iron Sheet Metal Truss Typology A Purlins Wooden Truss Corrugated Iron Sheet Typology B Metal Truss Purlins Wooden Truss Corrugated Iron Sheet Metal Truss Typology C Purlins Long Wooden Truss Corrugated Iron Sheet Long Metal Truss Typology B Short Wooden Truss Wooden Truss Short Metal Truss Typology C Metal Truss Purlins Purlins Corrugated Iron Sheet Long Wooden Truss Corrugated Iron Sheet Long Metal Truss Short Wooden Truss Short Metal TrussD Typology Purlins Typology C Wooden Truss Corrugated Iron Sheet Long Wooden Metal Truss Truss Long Metal Truss Purlins Short Wooden Corrugated IronTruss Sheet Typology Short Metal Truss D Purlins Wooden Truss Corrugated Iron Sheet Metal Truss Typology E Purlins Wooden Truss Corrugated Iron Sheet Metal Truss Typology D Purlins Wooden Truss Corrugated Iron Sheet Typology E Metal Truss

4 n°4 4 4 n° 4n° 4 4 4 n° 3 3 n° 2 24 n° 43 3 2 n°2 n°3 3 32n° 2 3 n°3 3 3 n° 3n° 3

42,60 42,60 ml 249,60 42,60 42,60 ml 249,60 42,60 ml 42,60 249,60 42,60 42,60 ml 249,60 37,42 37,42 ml 25,33 42,60 25,33 ml 42,60 218,20 249,60 37,42 37,42 25,33 25,33 ml 218,20 ml 42,60 37,42 42,60 37,42 177,60 25,33 ml 25,33 218,20 42,60 42,60 ml 177,60 37,42 37,42 ml 148,00 42,60 ml 42,60

m-2 145,60 m2 145,60 -2 m 145,60 m-2 145,60 m2 -2 m 126,90 145,60 m-2 m-2 126,90 103,60 -2 m 126,90 m-2 103,60 m2 85,80 -2 m

69,00 120,00 cost(birr)/ 69,00 69,00 100,00 120,00 cost(birr)/ 69,00 69,00 100,00 cost(birr)/ 120,00 69,00 69,00 100,00 120,00 cost(birr)/ 69,00 69,00 100,00 120,00 cost(birr)/ 69,00 69,00 120,00 cost(birr)/ 120,00 69,00 69,00 100,00 69,00 100,00 120,00 69,00 120,00 cost(birr)/ 69,00 cost(birr)/ 69,00 100,00 69,00 120,00 120,00 69,00 69,00 100,00 cost(birr)/ 120,00 69,00 69,00 100,00 120,00 cost(birr)/ 69,00 69,00 100,00 120,00 cost(birr)/ 69,00 69,00 100,00 cost(birr)/ 120,00

2,76 4,80 cost (€)/ 2,76 2,76 4,00 4,80 cost (€)/ 2,76 2,76 4,00 cost (€)/ 4,80 2,76 2,76 4,00 4,80 cost (€)/ 2,76 2,76 4,00 4,80 cost (€)/ 2,76 2,76 4,80 cost (€)/ 4,80 2,76 2,76 4,00 2,76 4,00 4,80 2,76 4,80 cost (€)/ 2,76 cost (€)/ 2,76 4,00 2,76 4,80 4,80 2,76 2,76 4,00 cost (€)/ 4,80 2,76 2,76 4,00 4,80 cost (€)/ 2,76 2,76 4,00 4,80 cost (€)/ 2,76 2,76 4,00 cost (€)/ 4,80

11.757,60 470,30 20.448,00 817,92 tot (birr) tot (€) 17.222,40 688,90 11.757,60 470,30 14.560,00 582,40 20.448,00 817,92 63.988,00 1.741,60 tot (birr) tot (€) 17.222,40 688,90 11.757,60 470,30 14.560,00 582,40 tot (birr) 1.741,60 tot (€) 20.448,00 817,92 63.988,00 17.222,40 688,90 11.757,60 470,30 14.560,00 582,40 20.448,00 817,92 tot (birr) tot (€) 63.988,00 1.741,60 17.222,40 688,90 7.745,94 309,84 14.560,00 582,40 13.471,20 538,85 1.741,60 tot (birr) tot (€) 63.988,00 3.495,54 139,82 11.757,60 470,30 6.079,20 243,17 tot (birr) tot (€) 20.448,00 817,92 15.055,80 602,23 17.222,40 688,90 12.690,00 507,60 7.745,94 309,84 14.560,00 58.537,68 582,40 1.559,49 13.471,20 538,85 63.988,00 1.741,60 3.495,54 139,82 6.079,20 243,17 tot (birr) tot (€) 15.055,80 602,23 tot (birr) tot (€) 8.818,20 352,73 12.690,00 507,60 7.745,94 309,84 15.336,00 613,44 58.537,68 1.559,49 13.471,20 538,85 12.254,40 490,18 3.495,54 139,82 10.360,00 414,40 tot (birr) tot (€) 6.079,20 46.768,60 243,17 1.257,30 15.055,80 602,23 8.818,20 352,73 12.690,00 507,60 15.336,00 613,44 tot (birr) tot (€) 58.537,68 1.559,49 12.254,40 490,18 7.745,94 309,84 10.360,00 414,40 13.471,20 538,85 46.768,60 1.257,30 tot (birr) tot (€) 10.212,00 408,48 8.818,20 352,73 8.580,00 343,20 tot (birr) tot (€) 15.336,00 613,44 40.009,14 1.061,52

Typology A

m-2 145,60 m- 2 126,90 m-2 126,90 103,60

42,60 ml 249,60 37,42 37,42 25,33 25,33 ml 218,20

Corrugated Iron Sheet Long Wooden Truss Long Metal Truss Short Wooden Truss Short Metal Truss D Typology Purlins Wooden Truss Corrugated Iron Sheet Metal Truss Purlins Corrugated Iron Sheet Typology D

4 n° 3 3 2 2 n° 3 3 2 2 n° 3 3 n°

Wooden Truss Metal Truss Typology E Purlins Wooden Truss Corrugated Iron Sheet Metal Truss Purlins Corrugated Iron Sheet Typology E

3 3 n° 3 3 n°

42,60 42,60 ml 177,60 37,42 37,42 148,00 ml

m-2 103,60 85,80

Wooden Truss Metal Truss Purlins Corrugated Iron Sheet

3 3 -

37,42 37,42 148,00 -

37,42 37,42 25,33 25,33 ml 218,20 42,60 42,60 177,60 ml

120,00 cost(birr)/ 69,00 69,00 100,00 120,00 69,00 120,00 cost(birr)/ 69,00 100,00 69,00 120,00 69,00 120,00 cost(birr)/ 69,00 69,00 100,00 120,00 69,00 100,00 cost(birr)/

4,80 cost (€)/ 2,76 2,76 4,00 4,80 2,76 4,80 cost (€)/ 2,76

20.448,00 tot (birr) 17.222,40 7.745,94 14.560,00 13.471,20 63.988,00 3.495,54 6.079,20 tot (birr) 15.055,80

4,00 2,76 4,80 2,76 4,80 cost (€)/ 2,76 2,76 4,00 4,80 2,76 4,00 cost (€)/

12.690,00 7.745,94 58.537,68 13.471,20 3.495,54 6.079,20 tot (birr) 15.055,80 8.818,20 12.690,00 15.336,00 58.537,68 12.254,40 10.360,00 tot (birr) 46.768,60

507,60 309,84 1.559,49 538,85 139,82 243,17 tot (€) 602,23 352,73 507,60 613,44 1.559,49 490,18 414,40 tot (€) 1.257,30

m2

69,00 120,00 cost(birr)/ 69,00 69,00 100,00 120,00 69,00 100,00 cost(birr)/

2,76 4,80 cost (€)/ 2,76 2,76 4,00 4,80 2,76 4,00 cost (€)/

8.818,20 15.336,00 tot (birr) 12.254,40 7.745,94 10.360,00 13.471,20 46.768,60 10.212,00 8.580,00 tot (birr) 40.009,14

352,73 613,44 tot (€) 490,18 309,84 414,40 538,85 1.257,30 408,48 343,20 tot (€) 1.061,52

85,80

69,00 120,00 69,00 100,00

2,76 4,80 2,76 4,00

7.745,94 13.471,20 10.212,00 8.580,00 40.009,14

309,84 538,85 408,48 343,20 1.061,52

m2

817,92 tot (€) 688,90 309,84 582,40 538,85 1.741,60 139,82 243,17 tot (€) 602,23

Lisa Germain, Matteo Persanti, Lorenzo Piras

BUILDING

TYPOLOGY

RESUME

43 m²

Typology E

G+0

Foundation Ground floor Wood joist floor Roof

3.001,02 1.381,07 2.286,96 1.061,52

7.730,58

179,78 €/m²

Typology A

G+1

126 m²

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Roof

5.472,34 2.124,71 4.339,84 9.613,03 4.339,84 1.741,60

Typology B

148 m²

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Roof

5.386,66 2.024,30 4.305,70 9.543,43 4.305,70 1.741,60

27.631,34

219,30 €/m²

Typology A

G+2

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Platform frame Wood joist floor Roof

5.472,34 2.124,71 4.339,84 9.613,03 4.339,84 9.613,03 4.339,84 1.741,60

Typology B

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Roof

4.593,40 2.107,99 3.631,92 9.058,04 3.631,92 1.559,49

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Platform frame Wood joist floor Roof

5.386,66 2.024,30 4.305,70 9.543,43 4.305,70 9.543,43 4.305,70 1.741,60

Typology C

108 m²

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Roof

3.650,93 1.564,38 2.845,99 7.407,02 2.845,99 1.257,30

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Platform frame Wood joist floor Roof

4.593,40 2.107,99 3.631,92 9.058,04 3.631,92 9.058,04 3.631,92 1.559,49

Typology D

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Roof

3.001,02 1.381,07 2.286,96 6.827,32 2.286,96 1.061,52

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Platform frame Wood joist floor Roof

16.844,86

195,87 €/m²

162 m²

37.272,70

181,64 €/m²

86 m²

Typology E

19.571,61

181,22 €/m²

205,2 m²

41.156,51

185,39 €/m²

Typology D

24.582,75

179,44 €/m²

222 m²

41.584,20

220,02 €/m²

137 m²

27.307,39

184,51 €/m²

189 m²

Typology C

3.650,93 1.564,38 2.845,99 7.407,02 2.845,99 7.407,02 2.845,99 1.257,30

Typology E

129 m²

Foundation Ground floor Wood joist floor Platform frame Wood joist floor Platform frame Wood joist floor Roof

29.824,62

184,10 €/m²

3.001,02 1.381,07 2.286,96 6.827,32 2.286,96 6.827,32 2.286,96 1.061,52

25.959,14

201,23 €/m²

Lisa Germain, Matteo Persanti, Lorenzo Piras