We have been on both sides of this. We have delivered projects that finished on budget, and we have inherited projects from other contractors where the money was already gone before we arrived. The failures we see are almost never down to one big mistake. They are a hundred small ones, compounded.
These are the eight practices that keep a Zimbabwean construction project on budget.
Fix the scope before you cost it
The single biggest cause of budget overrun is scope that was never properly defined. A client says "build me a house", the contractor quotes on a rough area, and three months later the client adds a garage, a second bathroom and granite worktops. Each addition feels small. Cumulatively they can double the cost.
Before a single quotation is issued, the scope should be fixed in writing: room schedule, finishes, fittings, external works. Any change after that is a variation with an agreed cost.
Get the drawings done — properly
Many Zimbabwean projects start on hand sketches and "we'll sort out the details on site". This is expensive. Detailed architectural, structural and services drawings cost money up front, but they eliminate the improvisation that generates most variations later.
For a house, you need at minimum: architectural layout, elevations, sections, structural layout, electrical layout, plumbing layout. For commercial and industrial work, the requirement is larger, and a quantity surveyor should prepare a bill of quantities.
Bill of quantities, not a lump sum
A lump-sum price tells you nothing about how the contractor arrived at it. A bill of quantities shows you the measured quantities of every item — concrete, brickwork, steel, finishes — and the rate applied to each. It lets you compare bids on a like-for-like basis, and it lets you see immediately when a variation adds cost.
Buy materials against the programme
Materials bought too early sit on site and deteriorate. Materials bought too late stop work. The programme should sequence procurement as carefully as it sequences construction. Long-lead items — structural steel, special finishes, imported fittings — must be ordered months before they are needed.
Where prices are volatile, fixing material costs early through supplier agreements is one of the most effective ways to protect a budget.
Pay against progress, not against promises
Payment schedules should be tied to measurable milestones: substructure complete, superstructure to wall plate, roof complete, first-fix services installed. Each milestone is inspected and signed off before the corresponding payment is released.
Retain 5–10% of each payment until the end of a defects liability period. This is standard, protects the client, and is expected by any reputable contractor.
Variations in writing, before the work
"While you're at it, could you also…" is the sentence that kills construction budgets. Any change — however small — should be captured in a variation order with a cost and a time implication, approved by the client before the work is carried out.
We hold weekly site meetings precisely so that variations can be discussed and documented while they are still small.
One decision-maker on the client side
When multiple family members, directors or committee members all give site instructions, the contractor cannot act coherently. One person on the client side should be the single point of contact, with authority to approve variations within an agreed limit.
Weekly reporting
A short, standard weekly report — progress against programme, photographs, list of open issues, materials on site — keeps both sides honest. If a project is going to go over budget, the client should see it coming months before it happens, not in the final account.
What a realistic contingency looks like
No project of any size finishes at exactly the initial number. Our guidance:
- New build, fully designed: 5–10%
- New build, informally designed: 10–20%
- Renovation of an existing building: 20–30%
- Refurbishment of an aged building: 30–40%
If a contractor presents a project with no contingency and assures you it will not be needed, you are being given optimism, not engineering.