What really goes into the cost of a 3-bedroom bungalow?

"How much will it cost to build a 3-bedroom house?" is the question we hear most. The honest answer is: it depends — on your plot, your design and, above all, your finishes. Rather than quote a number that may not fit your project, here's where the money actually goes, stage by stage, so you can plan with your eyes open.

1. Before you build: design and approvals

Professional fees and approvals are a small share of the total, but they shape everything that follows. A clear design, structural drawings and an accurate bill of quantities (BoQ) let you price the whole project before you start — and stop surprises later. You'll also need approved building plans from your county before construction begins.

2. Your plot

Two plots of the same size can have very different costs. Things to check early:

• Soil: black cotton soil, common in parts of the greater Nairobi area, usually needs deeper or specially designed foundations.
• Slope and access: steep plots and poor access roads add excavation, retaining work and transport costs.
• Services: how far you are from water, power and sewer connections — or whether you'll need a septic system, water storage or a borehole.

3. Foundation and substructure

Excavation, foundations, ground slab and damp-proofing. This is not the place to cut corners — mistakes here are the most expensive to fix later.

4. Walling and structure

Walls, columns, beams and lintels. The walling material you choose and the complexity of the design (number of corners, openings and levels) drive this cost.

5. Roofing

Roof shape matters as much as roofing material. A simple roof is cheaper and quicker than one with many hips, valleys and changes in level. Don't forget gutters, fascia boards and insulation.

6. Electrical and plumbing

Wiring, lighting, sockets, distribution boards, water supply, drainage, tanks and pumps. Planning these properly at design stage avoids chasing walls and redoing work later.

7. Finishes — the biggest variable

Ceilings, floors, wall finishes, doors, windows, kitchen, wardrobes, bathrooms and fittings. Two identical shells can end up at very different costs depending on the finishes chosen. This is where your design choices — and good advice — make the biggest difference.

8. External works

Often forgotten in early budgets: boundary wall, gate, paving and driveway, landscaping, external lighting and drainage.

9. Contingency

Set aside a contingency for the unexpected — price changes, ground conditions or a change of mind. Projects without one are the ones that stall halfway.

Where smart decisions save the most

• Finalise the design before you start. Changes during construction are the biggest cause of budget overruns.
• Price the whole project up front with a BoQ, not just the next stage.
• Buy the right materials, not the cheapest. Poor materials cost more in repairs and rework.
• Keep the design simple where it doesn't show and spend where it does — kitchens, floors and lighting.
• Get expert eyes on site at key stages to catch problems while they're still cheap to fix.