PERCENTAGE OF COST BREAKDOWN BETWEEN LABOUR, MATERIALS AND CONTRACTOR PROFIT IN CONSTRUCTION.
In large constructions costing kes 500m and above, a modest profit of between 10 to 20% is desirable. These are projects such as 6 storey and above high rise buildings in major towns such as in UpperHill area and over 10km long bitumen standard tarmac roads projects around the country.
In smaller construction projects between kes 20m to kes 500m, a profit margin of between 15 to 25% is desirable. These are mainly murram road projects and high-rise buildings less than 6 storeys in height.
In projects costing less than 20m, profit margins of between 20 to 35% is envisioned.
The larger the project cost, the smaller the % of profit.
LABOUR AND MATERIALS.
In most projects, labour costs approximately 25 to 35% of the total project costs, with materials taking the rest.
In interior design projects, the labour required is intensive and the tasks take longer and have to be carried out by highly skilled workmen e.g wood works requiring carpentry and joinery, art work, electrical/mechanical works.
Such works usually have a 50% ratio between labour and materials.
An average residential house construction will tend to have the usual 30% labour versus 70% material costs. Within the construction, some tasks will have more % of labour than others.
For example, foundation works are mainly labour based during excavation and backfilling. Walling, windows, doors, plaster will have less % of labour compared to materials, approximately 20% labour. Roofing, fittings, fascia board, paint, electrical works, plumbing works will mainly have more % of labour compared to materials, approximately 40 to 50%.
The total works will bring the average to 30% for labour and 70% for materials.
Francis Gichuhi Kamau, Architect.