Do I need a quantity surveyor to build a house in Kenya?

What a quantity surveyor actually does on a house

Three things. Before you build, they tell you what the house will cost. When you choose a contractor, they give every contractor the same list to price so you can compare. During the build, they check each payment against the work done. Everything else is detail.

When you do need one

• You are hiring a contractor. Without a bill of quantities you are comparing lump sums that assume different things. The cheapest quote is often the one that has left the most out
• You are borrowing to build. Banks and SACCOs normally ask for a bill of quantities or cost estimate from a quantity surveyor before they lend, and release the money in stages against valuations
• You are not there. If you live abroad or in another town, someone independent has to confirm that the money sent matches the walls built
• The budget is tight. If running out of money at roof level would be a disaster, you need to know the real cost before you start
• The house is large or unusual. More storeys, a basement, a sloping plot or high-end finishes all widen the gap between a guess and the truth

When you may not

If you are building a modest house in stages, paying for each stage from savings, buying the materials yourself and visiting the site most days, a full service is more than you need. You are your own cost control.

Even then, two small pieces of work are worth having: a material schedule, so you know how many blocks, bags of cement and lengths of steel each stage needs and nobody over-orders on your account; and a cost estimate for the whole house, so you know before the foundation is dug what the roof and finishes will come to.

What goes wrong without one

• The house stalls at the slab or the ring beam because the early estimate was a guess
• The contractor is paid 70% of the money for 50% of the work, and has no reason to hurry
• Extras appear at the end for items the quote never included: the septic tank, the gate, the wardrobes, the electrical fittings
• Materials are over-ordered and leave the site by the back
• A change you asked for casually comes back as a large bill you cannot check

None of these is rare. Each one usually costs more than a surveyor's fee for the whole job.

What it costs

The fee depends on the size of the house, how complete the drawings are and how much of the service you take. You do not have to take all of it. Common choices for a house are:

• A cost estimate only
• A bill of quantities, or a material schedule for an owner-managed build
• A review of a contractor's quotation before you sign
• Valuations at each payment stage

I quote a fixed fee in writing for whichever you choose, after seeing the drawings and before any work starts.

Is a quantity surveyor required by law?

For a private house the approvals you need are for the building itself: county approval of the plans, registration of the project with the National Construction Authority, and environmental approval where it applies. Your architect and engineer handle the design side. Using a quantity surveyor on a private house is a choice. On public projects and bank-financed ones it is in practice a requirement.

Questions clients ask