The most important factor in saving costs will be to ensure you have an optimum designed house floor plan. This means that all the spaces are architecturally designed to avoid unused wasted space. As a general rule of thumb, circulation space i.e. space used for corridors e.t.c should not be more than 20 % of the floor area.
Plot sizes are increasingly getting smaller and smaller in Kenya. The average size of a plot in Nairobi is 50 feet by 100 feet. This means that architects have to be very ingenious in design so as to fit in the maximum number of residential units in case of flats and apartment designs.
Room sizes can be designed with the furniture in mind and living room and kitchen doors placed in the middle where the circulation space passes inside the room as opposed to along one edge of the room.
For residential units for rent, the living room can be joint to the dining room to save space since if both rooms are created, they will take in more space.
Careful use of minimum practical dimensions can also greatly reduce costs. For example, the width of a toilet can be reduced up to 800mm and corridor width can reduce to 1.2 meters.
The door swing placement should also be carefully selected such that the doors swing to the edge of the wall in bedrooms so as to leave ample space inside the room. Care should be taken to avoid the bedroom doors opening with the full bedroom view for privacy reasons. Inbuilt wardrobes also reduce cost of wardrobe constructions.
Use of angle parking as opposed to 90 degrees parking also increases the number of vehicles that can park within a unit.
Roof pitch can also reduce the cost in that a less stepper pitch covers less surface area than a steeper pitch.
Lastly, the floor to ceiling height can be kept to a minimum of 2.4 meters. This will reduce the costs in that the quantities of materials used in construction of the extra walling will be reduced.