Building Case Study on a Multi-functional Space by Aki Hamada Architects

DARSHAN VARSANI Building Case Study Multifunctional Space by Aki Hamada Architects Kanagawa, Japan

The following is a precedent case study of a multifunctional space carried out by myself. All the analysis and views are my own and how I perceive the building as a whole from design, construction and until the finished product.

ARCHITECTURAL INTENTION

The aim behind the purpose of the building was to provide an extension to the circuit board factory, where workers can have a social space but it can also be a place for exhibitions and to hold meetings. Also, the upper floor was designed with the local community in mind where they could use this space for any function they wanted to hold. The building is located in Japan, Kanagawa which is south of Tokyo.

Prevailing wind indicated by the arrows and orientation as indicated on the compass point.

The sun path of the building’s location as per the orientation.

There is a need for mechanical systems (heating & cooling) in some months but not all the time and hence, I believe it to be a hybrid building. Also, the fact there isn’t a defined function for the building means systems may or may not be required depending on the function that occurs on the inside. For example, in the winter months (Jan/Feb/Nov/Dec) heating via mechanical systems may be required. However, in months like April or May, the temperatures outside are moderate and comfortable that the inside doesn’t need to be heated or cooled through mechanical ventilation.

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It is said to be a sub-tropical climate therefore, the winters are short and cool but the summers are generally hot and humid where there is also a lot of rainfall.

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The external temperature is about 10oC in the winter months and in July or August, it ranges from 29oC - 31oC on average.

Due to the building being designed to be a multifunctional space it was to key to having no structure like columns in the middle of the floor plan so it could be used for pretty much anything that the dimensions of the building allowed.

The physical context does allow for decent passive ventilation to occur and receive sunlight which is aided by the NW-SE orientation, however, it isn’t fully exposed on all sides and hence may not be well lit at all times due to the surrounding context.

THEORY -

S T RAT E GY

The open plan concept with the added flexibility of the sliding screens is an advantage to help with the multifunctional space concept. A slight disadvantage to the way these screens are used within this building is that they only move in that same direction of the line which leaves a lot of the screens sticking out from the side when the full thing is opened up. So by having a rotating mechanism that would allow it to be manoeuvred to one corner of the building which would allow it to achieve a fluid open plan concept.

The planning of the space and how sockets and environmental systems are beneath the floor plate allow for this concept to work but also planning the fixed spaces towards the back of the floor plan allows the open and multifunctional idea and strategy to work. As this means ventilation and lighting can get to the space that would be used more and that would allow more functions to occur in this space for the workers and the local community. However, by placing the kitchen and toilet spaces towards the back where it is close to the neighbouring building means smells would buildup between the two buildings. This means stale air will circulate this vicinity even when passive ventilation occurs. Hence, air purification systems may need to be put in place, to generate fresh air circulation.

The idea of having all the glazing on a track system so it can open up to the outside space which also serves the purpose of passive ventilation especially from the prevailing wind direction. This is great as it is a sustainable way of ventilating the space rather than just relying on mechanical systems. However, cross ventilation would be more efficient if the upper glazing was operable. As this would mean air would move through the space high to low meaning better and efficient ventilation of the space and hence less reliance on mechanical systems.

STRUCTURAL DESIGN

S T RAT E GY

0.4mm zinc sheet sealing membrane.

Triple glazing in aluminium frame.

0.4mm zinc sheet cladding.

Galvinised steel sliding element.

Triple glazing sliding element.

20mm cypress board decking.

15mm birch parquet flooring with 12mm plywood sheet beneath.

External steel staircase.

Pine roof rafters.

Pine space frame element.

Pine beam 150mm/300mm.

Pine bracing element.

Pine beam 150mm/300mm.

Pine column.

Concrete slab.

Concrete strip foundations.

Suspended floor on steel jacks.

Primary structure

Secondary structure

Tertiary structure

Wind Loads (Live) Dead Loads Live Loads Reaction Force

The bottom diagram shows the load path through one structural bay from the roof structure down which includes the bracing and space frame elements. The bracing indicated by the blue colour goes into tension as it receives wind from the right (blue arrow) and the opposing element goes into compression and vice versa. There is a similar continuation of load paths down to the foundations which are then distributed down into the earth.

CONSTRUCTION

DESIGN

S T RAT E GY

Excavation of site and strip foundations put down since it is a lightweight building and only two storeys.

Ground floor slab laid which has a sunken centre for the suspended floor allowing services to be run beneath it.

Columns and beams of the primary structures for the first floor are fixed with bolted connections.

Secondary structure for the ground floor is fixed (bracing and space frame) and also the floor structure fixed.

This is then repeated for the 1st floor following the same steps as the ground floor but the roof structure is also fixed.

The floor and brise soleil panels are fixed to the structure along with the external staircase.

The glazing curtain wall is fixed to the building on a sliding system.

Here the ductwork and electrical systems are installed which are accessible via the floor.

The sliding system with the Japanese paper is installed giving flexibility to how space is used. Also, the external shading element is installed.

Finally, the kitchen units and toilet fittings would be installed making the building complete.

E N V I R O N M E N TAL D E S I G N

March 21st

December 22nd

S T RAT E GY

June 22nd

Without Shading Device

With Shading Device

The above show how the shading device does help filter the light intensity but not as much as you think it would. Hence, the Japanese paper on the space frame and the sliding walls would help aid the reduction of light intensity.

The energy usage is mainly from the mechanical and electrical systems for sockets but also cooling and heating along with the artificial lighting.

Due to the building able to adapt to passive and mechanical usage when required the energy isn’t used by heating or cooling systems as much as the sockets that power appliances. However, this does not consider the fact it is a multifunctional space and hence may not be as accurate. Also, generally, it is overlit but the analysis doesn’t take into account the surrounding context and other devices used to help aid this.

The plant room I assume is located in the substrate factory which neighbours this due to the fact this building is an extension of the factory. The reason why I say this is that there is no designated area within the plan and it isn’t a space with a regular function. The systems are installed within the areas highlighted in the diagrams above which holds the ductwork for the heating and ventilation systems along with the electrics to power the lights and sockets. There doesn’t seem to be a very technical system to handle rainwater and doesn’t seem to make use of it within the building which may be due to the fact its a multifunctional space with an irregular use pattern. However, the roof slopes to one corner which allows the water to run off the roof in which the overlap takes it away from the building.

E N V I R O N M E N TAL ANALYS I S

Passive Ventelation Due to the glazing that surrounds the plan not being fixed, it works on a sliding track system, it can passively ventilate as mentioned previously. However, on the facades I indicated as being close to the neighbouring buildings means cross-ventilation can’t occur and hence smells would build up in this area which is why there is a need for an HVAC system with air purifying capabilities to keep the smells pleasant within the building.

Summer Lighting Comfort The high summer angle of the sun is controlled using the overhangs that go beyond the plan of the building but still allows some to enter. On the first floor, Japanese paper is used to help aid the high levels of sunlight intensity entering to provide an ambient feel to the space for whatever function it is holding.

Winter Lighting Comfort In the winter the sun angle is low and hence has more of a chance of entering the building through the glazing curtain wall that the facade of the building is. So to control this the building has a sliding screen which can be positioned along the outer facade as highlighted. This can help give a reasonable space that functions can occur in.

Artificial Lighting The building does make use of artificial lighting for evening and night functions to occur. It uses up lighting instead of downlighting. This could be because down lighting creates a high intensity of light concentration making certain areas lighter than the others.

Whereas, uplighting eliminates this which gives a pleasant and ambient environment to the whole space. They are located in the place as indicated on the sketch which is hidden meaning there are no wires exposed which may hang down.

Venteleation Control The facade device which allows a less intensity of sunlight within the building can also help with wind ventilation by reducing how much it allows in as the gaps can slow it down to give a more pleasant environment. This is helpful if there are strong winds and there’s a need for ventilation even though its intended purpose is not for this.

Venteleation & Lighting Control The sliding screens help with decreasing the intensity of light in which maybe other functions in that space may require more and hence the Japanese paper helps with this. Also, the screens help with ventilation where you are able to ventilate the plan efficiently but if there was a strong breeze then if paperwork is on the table it may blow it away and hence the screens can aid this also.

THEORY -

D E TAI L

The building is perceived to be a hybrid building and hence has HVAC systems within the building. These are placed in the areas where it is indicated in blue and is left exposed as this wasn’t a concern for a building that isn’t in use regularly. the electrical power output is indicated in red which are accessed via the floor.

Also, the vents for the heating and cooling output are also located within the floor meaning there is clear floor space.

The exterior facade shading device isn’t just panels of different sizes in width with variants on the gap between each. Instead, they are all tilted to a specific angle. This allows the light incoming from sunlight to be deflected to different parts of the space as well as blocking some. This would reduce the intensity of light but also spread the light within the building so there aren’t high concentrations of light thus creating an ambient feeling within the space.

The space frame uses a component made of steel to combine all the elements with a simple bolt fixing to form the frame and the beams for the sliding pine screens with Japanese paper. By creating this bespoke component it meant that when on-site, construction would be a quicker process. However, a lot of time would have gone into testing and designing the component for the concept of an open plan and adaptable space to be created.

I N T E G RAT E D

D E TAI L E N V E LO PE

STUDY

150mm X 300mm pine beam.

150mm X 300mm pine beam.

Ductwork & electrical services for power outputs for first floor.

Pine space frame structural element.

Triple glazing fixed with aluminuim frame- 5mm float glass + 12mm cavity + 5mm float glass.

Insulation beneath glazing element to prevent air leakage in fixing and construction joint.

0.4mm zinc sheet cladding to protect structural element for brise soleil and prevent rain from seeping through.

Sliding triple glazing element in wooden frame: 5mm float glass + 12mm cavity + 5mm float glass.

Sliding ability allows the space can be opened out to the external surroundings.

Shading device as a sliding element to use when required and each galvanised steel panel is tilted towards different angles to spread and diffuse ligh in all areas of the building.

15mm birch parquet on 12mm plywood placed on suspending jacks for services to run.

Mechanical heating and cooling outlet grille.

Sliding track system for glazing.

Insulation for joint between concrete, glazing and wooden floor to be air tight.

Sloping reinforced concrete slab to let water run off and not enter the building.

Reinforced concrete slab that transfers the load to the foundations and allow for walkway.

Sliding track element for shading facade to be used when required which is why this element makes it easier.

The circle shows where there is no insulation between the ground and the first floor of the building means there is a break in the thermal line and hence is a potential leakage point for heat or even a cool environment that there is within the building. By insulating this area it would mean less requirement to use the mechanical systems to keep the internal environment pleasant.

The blue ellipse shows where the damp proof membrane is in the envelope makeup of the building which shows there are minimal amounts. Also, there isn’t a continuous line of the DPM and hence likely to have leakage seeping through to the structure. This could then affect structural stability and decrease its life. Which in this case may be that they didn’t want to provide long life to it as its an extension to a factory and also a multifunctional space and hence may have had the strategy to just get the building done on a low budget and quickly.

SUCCESSES

The use of the space frame has allowed for the open concept with adaptability in which the pine framed Japanese paper screens can be used to organise spaces within the allotted space. The simplicity in the construction of the space frame along with having flexibility built into it is a great success.

This is due to the fact it’s supposed to be a multifunctional space and hence this strategy fulfils this.

Also, the fact it serves the local community as well means that having this strategy doesn’t restrict programmes that can occur within the floor area.

The structural components are made out of wood and are prefabricated off-site to be put together onsite. I think that this is a success within the strategy of the building. Knowing that this is a multifunctional space that probably isn’t in use at all times using wood as a material is effective and a sustainable solution especially when its only two storeys tall and hence this construction can withstand the loads for this height. Also, the fact it’s prefabricated saves time-on-site and allows for rapid construction meaning that space can be used in a quicker time.

The building isn’t heavily reliant on the mechanical systems that are installed within the building. It can also use passive strategies by opening up the glazing or placing the shading device for effective use and hence its efficiency to be as sustainable as possible does help and contribute to the sustainable environment. The use of local material such as the Japanese paper to diffuse light coming from the fixed glazing also is a great way of reducing light intensity. Being locally produced means there are low carbon emissions in the process.

FAILURES

There could have been a better strategy for the passive ventilation for the back of the building due to the build-up of smells near the buildings that neighbour it. This is due to the fact it’s in close proximity with only a few metres between it. If maybe a water feature was put in it would have aided with fresh air to re-circulate back in and not give off bad odours. An example of this is shown in the image to the right where the atrium in the Manitoba Hydro Place has this feature to pass ventilation through it and give fresh air which doesn’t have bad odours, but also dehumidify and humidify the air depending on the season.

I think that making the fixed glazing above the sliding elements operable would have helped with effective ventilation as the air moves from down to up as then cross ventilation can occur and help with bad odours at the back of the building where it can send air out upwards above the neighbouring building. This would mean less reliance on air purifying mechanical systems that are built into the HVAC system that building has installed in it Finally, the building doesn’t have a continuous line of insulation and waterproofing membrane. This means it is more likely, in terms of waterproofing, to cause structural damage where water can get through the gaps within the outer panels hence less longevity in the building’s life span. Also, it doesn’t have continuous thermal line meaning that the internal environmental conditions can escape.

The image on this page is sourced from https://transsolar.com/projects/manitoba-hydro.

D V DARSHAN VARSANI