It is necessary to plan the building before the commencement of building. The reason for this planning cannot be over-emphasized. There are two important aspects in the planning of building. These are:
1. Selection of site: In Nigeria, the ownership of land is by individuals. Each individual who wants to build a house in one’s land should take the shape and nature of the land into consideration in the design of the building so that one would get maximum ventilation in the house and make best use of it. One who wants to buy land should consult professionals to get best shape of land and the land suitable for the type of building one wants to develop.
2. Design of building: This involves the arrangement of rooms in the building plan. This is usually done by Architects. The owner should give the Architect brief of what he wants. This would include whether the house would be single storey or double storey building. It is noted that two storeyed building proves about 20% economical than single storeyed building. The number and arrangement of rooms should be such that all the requirements of the owner are fully met and inter-relationship of various rooms is such that the owner feels very little disturbance in his house-hold activities. In general, local, social and economic conditions control the design of the building.
Desirable inter-relationship of various rooms
- Living room or parlour, dining room, pantry, kitchen and store should be located in one row and should be inter-connected.
- Bedroom, office room, box room, dressing room, bathroom and water closet (W.C.) should be inter-related.
- Bedroom and living room should be connected through a covered corridor or lobby.
In the design of buildings, effort should be made to make out most use of the natural resources such as wind and sun. This is known as ORIENTATION OF BUILDING. Site plan usually show the orientation of land with respect to North. To make best use of sun for warmth and natural light, the home’s main living areas (or rooms used a lot) should face North. The main glazing in the house such as windows and glass doors should also face North. Anywhere between 200W to 300E of true North is fine. It is also necessary that least disturbance is caused and least movements are required to be made by the occupants of the house. Table 1 shows the required minimum area of various rooms of residential building.
Table 1; Required minimum area for various rooms of residential building
Arrangement of rooms, position and purpose
Living room/parlour: It should be well ventilated and lighted with natural fresh air and sun. It should be centrally located in the building and should have direct approach from the main entrance of the building.
Dining room: It should be located adjacent to the living room or it should be combined with living room into one big-sized room. It should remain directly connected to the kitchen so that catering of food is easy. It should be fitted with one or two cupboards and should have wash basin at one of the corners.
Bedroom: It should be located at one side of the building and should have at least one of its walls as an external wall so as to maintain good natural ventilation and light. It should be directly in front of prevailing direction of wind. It should have ample windows and ventilators and all the doors and windows should be protected from direct sun and rain.
Guest room: The room should be located on one side of the front verandah. It should not have any connection to other rooms except the dining room. Bath and W.C. should remain attached to this room, so that privacy of the other rooms is not exposed to the guests.
Kitchen: It should be located at the back corner of the house such that smoke of the kitchen does not spread in all the rooms of the house.
Store: If provided, it should be attached to the kitchen.
Pantry: It is a small room attached to the dining room. Cooked food is kept in this room. It should have cupboards and shelves.
Bath and W.C: The following points should be considered here
- Bath and W.C may be separate or combined in one room.
- If bath and W.C. are to be attached with a bedroom, they are generally combined.
- Both bath and W.C. should be well ventilated.
- There should be a least one separate bath and W.C. in the house extra than those combined with the bedrooms that all other members of the family my use it.
- A combined lavatory block (bath and W.C. usually called toilet) should be fitted with wash basin, bath tub, shower, fresh water point, hot water point, W.C., shelves, toilet-racks and brackets etc
- All the bath and W.C. should have at least one of their walls as external walls so as to facilitate proper ventilation.
- Window and ventilators should be 1.5 m above the floor level.
- Its internal walls should be plastered and finished with glazed tiles or mosaic finishing.
Verandah: Verandah should be located in front and back of the building or other important exit points.
Garage and servants room: They can be put at back open space of the plot.
Corridor: It is a covered place in the building with the help of which any room can be approached without disturbing privacy or working of the other rooms.
Lobby: It is a hall at the main entrance which remain connected to the other parts of the building through corridors.
Porch or portico: It is constructed in the front of the building. This adds to the elevation of the building. Cars can be temporarily parked in it.
Box room: It is a small strong room located in the centre of the building. Valuable articles are stored in the room
Stair room: The following points are considered here.
- It should be located at such a position that it remains approachable from all parts of the building.
- It should be well lighted and ventilated.
- The width of the flight of the stair should lie between 1 m and 1.5 m depending upon the traffic it has to handle.
- Free headway in case of stair should be at least 2.2 m.
- It is preferable if stair has two flights with a landing between them.
- The relationship between rise (R) and thread (T) of a stair should be R = 40000/T where R and T are in millimeter. The values of R may vary between limits of 150 mm and 180 mm while the values of T vary between limits 250 mm and 270 mm.