UNDERSTANDING HILL ARCHITECTURE

UNDERSTANDING HILL ARCHITECTURE BY- ANKITA RANA B-ARCH 8TH SEM SECTION – A ROLL NO. - 1332781018

CHAPTER 1 1. AIM To understand the designing guidelines of hill architecture and hillside settlement development.

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2. OBJECTIVES To understand the concept of slope, contours and hills.

To understand the designing guidelines of hill architecture.

To understand the disaster resistance building design standards.

To study the general hillside building bye laws.

To study the origin and development of hillside settlement by taking case study of a hillside area which is along river.

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3. SCOPE Scope is to understand the designing considerations including building bye laws of hillside a rchitecture.

This research covers guidelines for planning and designing buildings on hills of Uttrakhand.

This study will explain how hillside settlements changes and develop according to time.

It also explains that how designing on flat land hilly area is different and what consideration s should be followed.

4. LIMITATIONS Hill architecture is limited to some parts of the India. Hence the study is limited to only Uttrakhand region of India.

This study is discussing only general guidelines of designing not detailed.

Planning and designing of structures in hilly region is very difficult. After using many disaster resistance techniques still there are chances that building would get effected by natural calamity.

This research is limited to present time. Does not cover vernacular construction techniques.

METHODOLOGY

STEP 1.

• Study of basic terminologies regarding hill architecture.

STEP 2

• Understanding Planning and design considerations.

STEP 3

• Getting information about various building bye laws followed in today’s world with the help various IS codes .

STEP 4

• Study of hillside settlement development by taking case study of Devprayag in Uttrakhand.

STEP 5

• Exploring the origin of the settlement and reasons for its development.

1. INRODUCTION          

Different and nature dependent architecture.

Dominated by slope.

Prone to natural calamities.

Land is predominantly mountainous.

Maintenance of natural form Full of natural vegetation.

Require different construction techniques.

Majorly cold climate.

Construction on limited area of hills. complex geological structure.

“No house should ever be on any hill … It should be of the hill, belonging to it.”

INTRODUCTION TO HILLS Any area having an altitude of more than 600 m from the mean sea level or an average slope of 30 degree may be classified as hilly in India, which includes • the Himalayas, • the Central Highlands, • the Deccan Plateau and • the north eastern hill ranges.

HIMALAYAN AREAS IN INDIA •

Stretch from Kashmir and Himachal Pradesh in North-West to Arunachal Pradesh and Nagaland in extreme North-East covering the whole of the Himalayan range.

Has wide Variations in • geology, • geomorphology, • climate, • altitude and • materials resources.

CLASSIFICATION OF HILLS Depending upon the altitude and prevailing climatic conditions, hill regions have been classified into categories as a) b) c)

FOOT-HILL REGIONS (BELOW 1200 M), MID-HILL REGIONS (1200–3500 M) OR SUB HIMALAYAS AND HIGH-HILL REGIONS (ABOVE 3500) OR HIGHER HIMALAYAS

Source - Regional Geology & Structure of the Himalayas

INTRODUCTION TO SLOPES A slope is the rise or fall of the land surface. A slope is easy to recognize in a hilly area. Slope is the measure of steepness or the degree of inclination of a feature relative to the horizontal plane. •

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Division of slopes from flat, gentle, moderate to steep slop es.

As the height of hill increases gradually more the slope beco me steeper.

CALCULATION OF SLOPES •Decide on an area for which you want to calculate the slope.

•Once you have decided on an area of interest, draw a straight line perpendicular to the contours on the slope.

•Measure the length of the line you drew and, using the scale of the map, convert that distance to feet.

•Determine the total elevation change along the line you drew.

READING CONTOUR PATTERNS ON A TOPOGRAPHIC MAP A CONVEX AND CONCAVE SLOPE A STEEP SLOPE AND A GRADUAL SLOPE

METHOD OF MAKING CONTOUR PLAN FROM 3D

CONTOUR LINES Contour lines, or isohypses, connect points of equal elevation.

Contour lines are curved, straight or a mixture of both lines on a map describing the intersection of a real or hypothetical surface with one or more horizontal planes.

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Concurrency: Contour lines never cross or divide.

Cliffs: May appear to merge on vertical cliffs, but are stacked.

Caves: May appear to cross in caves, but go under one another.

Hills and knobs are shown as closed, concentric contours.

Closed depressions and basins are shown as closed contours with hatches pointing downslope.

DEVELOPMENT ON SLOPES

Development allowed on Slopes below 30 % where the integrity of existing slopes is retained on submission of information.

1. DESIGN STANDARDS FOR SLOPING SITES 1.1 SITE AND SUBDIVISION DESIGN Larger manufactured slope should be located on the uphill side of the struct ure to reduce the appearance of gradi ng from the street.

NOT THIS

THIS

THIS

NOT THIS

Figure 15-Retain the shape of the natural landform

Figure 16- Reducing appearance of grading

Grading must be designed to preserve natural features such as knolls or ridgelines. In no case should the top of a prominent hilltop, knoll, or ridge be graded to create a large building pad.

THIS Small irregular berm are present on top of the slope.

Variety in slope bank grading creates a natural appearance mor e resembling nature.

NOT THIS

Natural drainage courses should be preserved, enhanced, and incorporat ed as an integral part of the project design to the extent possible.

Drainage features become very visible.

Engineered slope look forced and unnatural.

Figure 17- Contour Grading Techniques. Reference – Hillside management zone. Sierra Madre, CA. Initial cut and fill eart hworks for road

Adding material to the toe of a slope (buttressing), and removing material from the head of a slope, will usually in crease slope stability by reducing shear stresses and thereby diminishing the likelihood of landslides.

New cut to fill for building.

New cut to fill for building.

Figure 18- Grading and earth works.

2. DESIGN STANDARDS FOR SLOPING SITES CUTTING AND FILLING OF SLOPES Round edges of fill to blend with natural hillside.

Avoid angular intersection within natural contours.

Round top and bottom o f fill to be blend with nat ural hillside.

Cut and fill conditions

Figure 19- Design standards for sloping sites.

Reference-Planning policy guidelines Mauritius.

On each building site, careful consideration shall be given to the cut and fill conditions s uch that a balance is achieved where feasible and consistent with the intent of this chapter to minimize the visual impact of grading.

THIS

Terraced decks do not increase building bulk.

Building correctly fits into the ground and minimises the effect on the hillside.

Use low level decks and side decks.

Terracing reduces bulk.

Smaller overhangs for individual floors or wind ows help k up mass and protect against excessive sunlight.

NOT THIS Overhanging decks make buildings seem more massive .

High profile building stands out on the hillside. Avoid decks hanging from the down hill side.

Cantilever makes building appear taller, more monum ental.

Excessive roof overhang results in additional visual bulk.

The dimensions of a structure parallel to the direction of the slope shall be maximized in order to limit the a mount of cutting and filling and to better fit the house to the natural terrain.

The following cut and fill criteria are intended to ensure that new construction retains the existing landform of the site and follows the natural contours. a. access: driveway, parking and fire turnaround, if applicable b. house footprint c. cellar d. other areas including landscaping, hardscape and outdoor spaces Rounded edges resemble natural slope

Contour grading techniques shall be used to provide a variety of both slope percentage and slope direction in a threedimensional undulating pattern similar to existing, adjacent terrain.

BUILDINGS AND STRUCTURES ORIENTATION Single-level residential structures should be oriented such that the greatest horizontal dimension of the structure is parallel with, and not perpendicular to, the natural contour of the land.

Figure 47- Parallel orientation of building

Figure 46- Perpendicular orientation of building

ARCHITECTURE STANDARDS The dimensions of a structure parallel to the direction of the slope shall be maximized in order to limit the amount of cutting and filling and to better fit the house to the natural terrain.

THIS

Structure should fall below top of ridge elevation.

NOT THIS

Publicly visible exterior walls of any building shall be designed to avoid monoton ous or continuous facades.

A single, continuous vertical or horizontal plane on the front and rear facade of any building is not permitted.

Over-emphasized vertical structures disrupt the natural silhouette of the hillside.

THIS

The form, mass and profile of the individual buildings and architectural features shall be designed to blend with the natural terrain and preserve the character of the natural slope.

NOT THIS

THIS

NOT THIS

Avoid excessive cantilevers on downhill elevations.

Excavate underground or utilize below grade rooms to reduce effective bulk and to provide energy efficient & environmentally desirable spaces.

Large roof sections to parallel the slope Building envelop

Softening of larg e vertical surfaces

Rigid vertical segment

Figure 53- Avoiding excessive cantilevers

1. In harmony and visually blends with the natural environment, 2. responsive to site constraints and opportunities, 3. Compatible with the surrounding neighbourhood and 4. respectful of the rural character of the hillsides.

Figure 55-Figure 5- Building form reflects hillside form/setting

WORKS AND SERVICES ROADS AND ACCESSES

Figure 62- split level roads can reduce site disturbance

Figure 65-Modulated manufactured slopes to appear natural

Figure 63- Circulation should aligned to the natural grades

Roads should be laid out to avoid steep grades and should normally not exceed 1:8(12.5%).

Conventional road layouts & standards may have to be adapted and utilisation of one way and or split level roads to avoid excessive cuts and fills should be considered without comprom ising environmental, visual and public safety objectives

THIS

NATURAL ENVIRONMENT

NOT THIS

Planting naturally flows the average slope.

Open see through fencing blends into natural environment.

FENCES AND LANDSCAPING STANDARDS

FIGURE 36 - PLANTATION STOPS SOIL EROSION

Large retaining walls.

Clear cut separation between natural condition and developed area with no transition.

Landscaping shall be used to screen views of down slope building elevations.

No effective bulk. Planting pockets on stepped retaining wall allow screen planting at several levels.

Figure 35- Fencing with landscaping pattern

No planting possible due to toe of retaining wall. Large concrete retaining wall surfaces can be seen for miles and take years to conceal with planting and tress.

Slopes with require planting shall be planted with informal clusters of trees and shrubs to soften and vary the slope plane.

GUIDELINES FOR RETAINING WALLS

Landscaping with retaining wall Figure 21- Retaining walls with vegetation

A minimum horizontal distances as determined shall be maintained between each individual wall in the stepped wall system, and shall be landscaped.

Retaining walls should blend with the natural topography, follow existing contours, and be curviline ar to the greatest extent possible.

Landform planting

Conventional planting

Skyline planting

Irregular visual plane in cross -section.

Uniform visual plane in cross -section.

THIS Landform revegetation

Groundcover only for convex areas. Trees and shrubs clustered in concave areas.

Larger species at bottom.

Landform-graded slopes are characterized by continuous series of concave & convex forms interspersed with mounds that blend into the profiles, not linear in plain view and varying slope gradients, and significant transition zones between man-made and natural slope.

NOT THIS

Conventional landscaping

Trees and shrubs spaced for uniform coverage.

VISUAL QUALITY GUIDELINES Structures shall be designed so the slope angle of the roof pitch is generally at or below the angle of the natural hillside or graded slope.

View shed Protection:

Development below ridge line

scenic ridgelines

Placement of buildings

GEOGUIDES FOR SLOPE MANAGEMENT AND MAINTENANCE TYPES OF LANDSCAPE FAILURES ON HILLS

ROTATIONAL OR CIRCULAR SLIP FAILURES.

TRANSLATIONAL SLIP FAILURES.

DEBRIS FLOWS AND MUD SLIDES.

WEDGE FAILURES

LANDSLIDES IN SOIL Landslides occur on soil slopes and the consequences can include damage to property and loss of life. Soil slopes exist in all parts of Hilly region and can even occur in places where rock outcrops can be seen on the surface.

Weathering of soil Some major causes of landslide.

1) Falls of the parent material or residual soil from above, due to natural weathering processes.

2) Increased moisture content and consequent softening of the soil, or a rise in the water table. These can be due to excessive tree clearance, ill-consi dered soak-away drainage or septic systems, or heavy rainfall.

Unstabilised rock topples and travels downslope Vegetation removed Steep unsupported cut fails Discharges of roof water away rather than storing it

Structure unable to tolerate cracks Poorly compacted fill settles unevenly

Inadequate walling unable to support fill Inadequately supported cut fails

Roof water introduced in to slope.

Saturated slope fails

Dwelling not founded in bedrock

Vegetation removed

Absence of sub soil drainage within fill Loose, saturated fill slides and po ssibly flows downslope.

Ponded water enters slope and activates landscape.

Possible travel downslope which impacts other development downhill

Vegetation retained Surface water interception drainage

Watertight, adequately sited and founded roof water storage tanks ( with due regard for impact of potential leakage) Flexible structure Roof water piped off site or stored On site detention tanks, watertight and adequately founded . Potential leakage managed by sub soil drains Vegetation retained

Mantle of soil and rock fragments Pier footing into rocks Subsoil drainage may be required in slope Cutting and filling minimised in development Sewage effluent pumped out or connected to sewer.

Tanks adequately founded and watertight. Potential leakage managed by sub soil drains.

Engineered retaining walls with both surface and sub surface drainage ( construction before dwelling )

EARTHQUAKE RESISTANT DESIGN AND CONSTRUCTION OF BUILDINGS

Buildings having plans with shapes like, L, T, E and Y shall preferably be separated into rect angular parts by providing separation sections at appropriate places.

1.

STRENGTH IN VARIOUS DIRECTIONS The structure shall be designed to have adequate strength against earthquake effects along both the horizontal axes. The design shall also be safe considering the reversible nature of earthquake forces.

Regularity: Simple rectangular shapes behave better in an earthquake than shapes with projections.

Separation of Blocks: Separation of a large building into several blocks may be required so as to obtain symmetry and regularity of each block.

Simplicity: Ornamentation involving large cornices, vertical Figure 87- Torsion or twisting of unsymmetrical plans or horizontal cantilever projecti ons, facia stones and the like Enclosed Area: A small building enclosure are dangerous and undesirable with interconnected walls acts like a rigid from a seismic viewpoint. box.

Simplicity is the best approach.

CHAPTER 3 CASE STUDY – UTTRAKHAND HILL SETTLEMENTS The arrangement of houses in a tightly knotted-chain manner along river, main street, or valley is known as settlements in hilly region. These settlements acquired many pattern after evolution.

EVOLUTION OF SETTLEMENTS The advance of settlement first proceeded horizontally along major valleys and their tributaries and then vertically up valley sides.

Especially as settlement moved upslope into broken terrain, but perhaps also to some extent in valley s, the population became more dispersed because the occurrence of suitable combinations of water and soil were more localised than in valley bottoms. Settlements were small islands scattered through extensive tracts of tress.

CLASSIFICATION OF HILL SETTLEMENTS VALLEY SETTLEMENT

2.HILL TOP SETTLEMENT 3. SPUR SETTLEMENT 4. GAP SETTLEMENT

VALLEY SETTLEMENTS ADVANTAGES  Centrality,  Adequacy of space for physical expansion,  Easy accessibility of water,  Easy convenience of laying transport and utility services network.

Dwelling plan of Khurpatel

Figure 93-Khurpatal valley settlement

Figure 90-Chaukutia valley settlement

DISADVANTAGE Due to the presence of river system or water body and its catchment, loss of fertile lands.

HILL TOP SETTLEMENTS

TOWNS OF HILL TOP SETTLEMENT Towns sited on the ridge top have developed in a linear pattern. The main road passes throug h the ridge top and the main settlenet grows up on both sides of the road. Since the ridge tops are very narrow, there is no space for further extension widthwise, hence the township extends lengthwise. Chakrata, Mussoorie and Landsdowne are such examples.

Site plan - Design of hill top settlement

HILL TOP SETTLEMENTS: It’s an important strategic location since from early, colonial periods. Hence the Desig n abstractions were considered with the conception of those design principles to suit t he Hill Top location

ADVANTAGES  Healthy climate  Scenic beauty  Strategic position and free drainage

DISADVANTAGE  Virtual absence of flat land  Lack of water supply

Figure 98- Narendra nagar, Uttrakhand hill top settle ment

Narendra nagar, Uttrakhand is an example of hill top settlements which is developed for having scenic view of the natural beauty of mountains of Uttrakhand.

Figure 96- Site section and design of hill top settlement

These towns are connected with main roads which is the means of transportation for the people living in this town. These types of towns slowly converting into hill stations.

SPUR SETTLEMENT

The important aspect of Great Views towards Valley and Snow peaks makes these location special. Hence the Conception was made to highlight the natural views.

The Urban nodes and Settlement pattern should acknowledge these factors in first priority as well as to enhance the quality of spaces with in it.

ADVANTAGES  Transition between valley floors and hilltops  Natural defence  Panoramic Landscapes and  moderate climate Limited loss of agricultural field

Figure 102- Abstract site section of spur settlements

Spur location

Abstract site and region of spur settlement

BUILDING PATTERN IN SPUR SETTLEMENT

This conceptual sketch shows that how buildings develop along the road constructed.

This settlement can develop along upper side and lower side both if surfaces with less slope is available.

ABSTARCT SITE SECTION OF SPUR SETTLEMENT

This conceptual sketch shows that how buildings develop along the road constructed.

This settlement can develop along upper side and lower side both if surfaces with less slope is available.

ABSTARCT POSITIONING OF BUILDINGS IN SPUR SETTLEMENTS

The spur settlement is located at the transit ion point between valley floors and hilltop.

It is protected by natural defence at it is cov ered by natural vegetation.

But this nature also play a role for disadvan tage that there is lot of chances of landslid es in these areas.

This location has panoramic view. This regi on is protected from flash floods.

DISADVANTAGE OF SPUR SETTLEMENT 

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Restricted accessibility

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Difficult intra site mobility 

Frequent landslides Constraints in space for expansion

Figure 105-Dwelling plan in spur settlement Figure 107- Pauri, Uttrakhand Spur settlement

GAP SETTLEMENT TOWNS OF GAP SETTLEMENT Towns sited on river- terraces and valley- bottoms tend to acquire more or less a rectangular shape, the width of the rectangle depending upon the width of the available flat space. These type of towns have acquired the shape of tiere d rectangle, the number of tiers depending on the number of levels of terraces on which the township has sprawled.

ADVANTAGES OF GAP SETTLEMENT    

Enjoys Nodality Convergence of routes makes the transit points Immense Water availability Conceptual design of gap location

Gap location

Abstract site section of gap type of settlement

DISADVANTAGE • Constraints in space for expansion

Devprayag example of gap settlement Details of Design components

Srinagar, Uttrakhand - Gap settlement

Abstract design of gap settlement

INTRUODUCTION (DEVPRAYAG) It is a town and a nagar panchayat in Tehri Garhwal district I n the state of Uttarakhand, India, and is one of the Panch Pra yag (five confluences) of Alaknanda River where Alaknanda and Bhagirathi rivers meet and take the name Ganga or Gang es River.    

Elevation – 580 m Annual temperature- 22.7 degree Range of temperature – 17.7 degree Average Annual rainfall – 82 Cm

ORIGIN OF SETTLEMENTS IN DEVPRAYAG This region is one of the citadels of the hindu civilization and culture.

Pilgrimage associated with administration and trade gave birth to towns in the region in early historic times.

Devprayag

TOPOGRAPHY

Location of gap settlement

About 99% of Garhwal Himalaya presents a rugged, stony and hill topography including glaciated region. Garhwal Himalaya is a section of tertiary folded Himalaya Mountains composed of highly fossil ferrous marine sedimentary rocks.

DRAINAGE SYSTEM Devprayag is the first sacred river junction of garhwal Himalaya. It is here that the Ganga really originates.

Dendritic pattern is the most common with local radial pattern developed around hills and peaks.

Dendritic pattern settlement

Section of Devprayag area

C O N T O U R M A P

D E V P R A Y A G

VARIATION IN SUN EXPOSURES TO THE HILLS OF

DEVPRAYAG

Summer Time - 7:00 a.m

Winters, time - 7:00 a.m

Summer, time- 9:30 a.m

Winters, time - 9:30 a.m

Summer, time- 1:00 p.m

Winter, time - 1:00 p.m

Summer - time - 5:00 p.m

Winters - time- 5:00 p.m

DEVELOPMENT OF DEVPRAYAG FROM 2004 TO 2017

Devprayag in year 2004

Devprayag in 2010

Devprayag in 2017

DISTANCE FROM WATER SOURCES  

Plot limits shall be decided on the follow ing distance from water source.

Area to be compulsory left for tree planta tion at minimum 30.0-30.0 metre from riv er bank and minimum 10.0-10.0 metre fro m underground water source. No construc tion shall be allowed in this area.

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Construction shall be permissible at mini mum 5-5 metre from water passage or the required set back as per bye- laws whiche ver is more.

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No permission shall be given for any type of construction or development within 30.

00 metres range from the boundary of all lakes or the prescribed maximum level of reservoirs, in existence in Uttrakhand.

FINDINGS AND CONCLUSIONS

VULNERABILITY ASSESSMENT OF EXISTING BUILDING

VULNERABILITY ASSESSMENT OF EXISTING BUILDING