1.0 Introduction

The aim of the competition is to advance the use of steel in sustainable housing through the identification and application of best practices and innovative approaches. For each location in the competition, the intention is for the winning design to be built. The following section sets out the detailed building requirements for the Indian project.

2.0 Location 1: India

Summary of the building brief for India:

2.1 Building Type

The indicative requirements of the proposed building are set out below. These requirements should not constrain the innovation of entrants. In developing their entries in accordance with these requirements, entrants are reminded of the Adjudication Criteria set out in Article XIV.

The building is to be a five-storey apartment building comprising eight apartment units. Each apartment shall have a net useable floor area of 112 m2. The gross floor area, i.e. including communal areas, is 158 m2. All floors are to be serviced by lifts. The building will have a footprint of around 316 m2 and occupy a plot of land of around 600 m2.

Ground floor accommodation shall comprise:

• Enclosed car parking space for a minimum of eight cars
• Community hall
• Reception/guard room
• Mechanical and electrical plant room
• Staircase
• Lift core.

Floors one to four shall each comprise two apartment units, each providing the following accommodation:

• Living room
• Dining room
• Master bedroom
• Children's bedroom
• Guest bedroom
• Kitchen
• Two bathrooms
• Two balconies.

The building will require air-conditioning throughout although consideration should be given to how natural ventilation, cooling, shading, etc. can be employed to minimise the use of mechanical air conditioning.

2.2 Building Location

The building is to be built in Kolkata New Town, called Rajarhat, which is located 10km to the North-east of Kolkata's (formerly Calcutta) Central Business District and about 1km from Kolkata International Airport. The figure below gives the location of Rajarhat within the Indian sub-continent.

Rajarhat New Town is being planned as a major hub for business, trade, industry, institutions and culture. Though it is planned as a self-contained nodal growth centre, the New Town will be integrated fully with the future spatial and functional structure of the metropolis of Kolkata.

Prior to its development, the Rajarhat area was mainly used for agriculture. The building is are to be built within Action Area 1 of Rajarhat, New Town although the precise location of the building has not yet been agreed with the developer. The figure below shows the location of Action Area 1 within Rajarhat New Town.

When fully developed, Rajarhat will provide homes for around 750,000 people and cater for some 250,000 floating population.

Rajarhat will have high quality infrastructure including wide roads, bridges, large public open spaces including water-bodies, educational institutions, medical facilities, sports and cultural facilities in addition to basic infrastructure like water supply, power supply and drainage.

The New Town will have several town level activity focus areas such as a new CBD, major sports complex with world class facilities, a technology park, a central recreational park around the new CBD located in the heart of the New Town, a permanent exhibition/trade fair ground, a large institutional complex including a civic centre, an environment-friendly industrial complex, super speciality hospitals, business schools, technical university and an entertainment centre.

The Rajarhat area will be developed as per plan with parks and gardens provided at different places. Areas for business centre, shopping malls, schools etc. are already earmarked. These buildings will be in the residential area where parks/gardens are already planned.

2.2.1 Site Description

Topography
The site is in the plain of the Ganges in West Bengal. The terrain is generally flat as shown in the photograph below.

The soil characteristics within the Rajarhat area can be broadly classified as:

• Up to 4m of soft soil (average cohesion between 30 and 40 kPa) underlain by;
• 4 to 15m of silty clay with average cohesion between 20 and 30 kPa.

The water table is around 1 m below the existing ground level.

For buildings of less than five storeys, shallow foundations are sufficient. For buildings of five or more storeys, piled foundations are generally required.

Utilities
Electricity will be supplied to the buildings via overhead power lines. The building must also include the provision for a backup energy supply, typically a diesel generator, which should be acoustically insulated.

Domestic treated water will be supplied and buildings connected to a mains sewerage system. Gas, for cooking, is provided by LPG cylinders. Telephone connection is provided and TV/IT provision should be considered in the design.

2.2.2 Photographs

The following images show the area of Rajarhat in which the demonstration building will be constructed.

2.2.3 Climate

Rajarhat is situated on the North-eastern fringe of the city of Kolkata (Calcutta) about 50km south of tropic of cancer. The whole region is part of the great Ganges delta. The weather in the region is influenced by the Bay of Bengal and has a tropical climate with the summers being hot and humid. Temperatures during the summer months of May-June can rise to 43ºC and, during the winter months of December-January, the temperatures typically fall to around 8ºC. The climate is humid; humidity varying from 65-85% during the summer. Air-conditioning is required during the summer, supplemented with natural ventilation. Heating of buildings is not generally required.

From June to September, the average rainfall in the Kolkata region is 158 cm. Provision should be made in the design for the collection, storage and use of rainwater from the building/site.

The prevailing wind direction in Rajarhat is from the south during the summer and from the north during the winter. The average wind speed at Rajarhat is 50 m/s at 10m. Topographical features do not affect the wind speed. The area experiences frequent cyclonic wind during April to June with maximum wind speeds of up to 180 km/h typical.

Daylight hours are approximately 5.00 am to 6.30 pm during the summer months (April - June) and around 5.45 am to 5.00 pm during winter months (November - January).

2.3 Building user profiles

The proposed building is targeted at young professional couples and small families (3-4 persons), from the upper socio-economic classes, who are well educated and with relatively high income. The target building users are likely to be from the socio-economic classes SEC A1 and A2, as defined by the Market Research Society of India.

Many couples will both work and therefore these/some apartments will be vacant during working hours. For small families it is likely that the mother will stay in the apartment during the day to look after the child(ren).

Periodically, guests/parents, often elderly, come and stay with the families. People are generally religious and would like to keep provision for Puja (Prayer room/space) at home.

2.4 Other design issues

Buildings in Rajarhat are to be designed to be resistant to seismic activity. For the purpose of determining seismic risk, India is divided under four seismic zones. The city of Kolkata falls under Zone-III. The corresponding zone factor may be taken from IS:1893-2002.

The building should be sufficiently resistant against severe wind condition. The building is to be designed to comply with IS 875. In general there is a low flooding risk in the Rajarhat region; the last flood event occurring in 1978. However, the ground may be liable to isolated water-logging after periods of heavy and incessant rain.