Most budgets that go wrong were not wrong because of one big mistake. They were wrong because of five small ones nobody checked: a finishes schedule marked TBC, a missing line for temporary works, a subcontractor quote from last year, a contingency with no reasoning, a payment term nobody read. Any one is survivable. Together they sink a job.
This construction budget checklist is the run-through to do before a price goes out and again before you sign the contract. It works whether you priced the job yourself or had it priced for you.
Know what you are actually pricing
Before anything gets costed, make sure the scope is nailed down. Half finished drawings, missing specification pages and a "TBC" on the finishes schedule are the usual reasons a job runs over once it is on site. If the scope is not clear, say so in your qualifications when the price goes out. Do not guess and hope.
A useful habit: write a one-paragraph description of the job in your own words before you price it. If you cannot, you do not understand the scope well enough yet, and the gaps you stumble over while writing it are the ones to query. Keep that paragraph. It is a handy thing to compare against when the scope starts drifting later.
List every cost category, not just the obvious ones
Labour and materials get priced every time. What gets missed is everything around them. Go through the job category by category rather than relying on memory from the last similar contract, because no two sites are the same once you account for access and existing conditions.
- Site management. Supervision for the actual duration of the job, not the duration you hope for.
- Welfare and accommodation. Cabins, toilets, drying rooms, and the hire periods for each.
- Temporary works. Propping, shoring, hoarding, temporary roofs and edge protection.
- Access. Scaffold, towers, MEWPs, and any restrictions on deliveries or working hours.
- Attendances. What you provide to subcontractors: power, lighting, storage, skips, cleaning.
- Professional and statutory costs. Anything outside the measured work that you are responsible for under the contract.
- Waste. Muck away, skips and segregation, which are easy to underestimate on refurbishment jobs.
Price against current rates
Rates move. A price built on last year's subcontractor quotes without checking them again is a price that is already wrong before you have submitted it. Get fresh quotes where you can and price the rest against current market rates rather than a rate book nobody's touched in months.
Pay special attention to the packages that carry the most money. A small error on a large package costs more than a large error on a small one. If you only have time to re-check a handful of rates, start with those. Check material prices on the big-ticket items too (steel, timber, concrete, roofing) because those are the lines where a move in the market shows up fastest in your margin.
Contingency and risk, written down
Set a contingency figure and write down what it covers. Ground risk, access risk and anything unusual about the existing building all belong in that figure. A contingency with no reasoning behind it is the first thing that gets cut when the client pushes back on price, and then you are exposed with nothing to point to.
Written reasons also help you decide what to do when a risk does not happen. If the contingency was for unknown ground conditions and the ground turns out fine, you know that part of the money is genuinely available. Without the reasons, the whole contingency just becomes margin you hoped to keep.
A price can be right and still sink you. Check the scope, the rates and the risk, then check how and when the money actually arrives.
Construction budget checklist item: cash flow before you sign
A price can be right and still sink you if the payment terms do not match how the money goes out the door. Look at retention, payment periods and when your subcontractors and suppliers expect to be paid before you commit to the contract, not after.
The Construction Act (HGCRA 1996, as amended) gives you rights around interim payments, payment notices and suspension for non-payment, but it does not set your payment period for you and it does not fund your cash gap. Say, hypothetically, you pay your trades monthly and the contract pays you some weeks after each valuation. You are carrying that gap on every valuation, and on a busy job it adds up. Work it out before you sign, not when the overdraft limit tells you.
Review it, then ask one question before you sign
Have someone who did not build the price check it before it is submitted. A second set of eyes catches the item that got missed or the rate that was typed in wrong, and it costs you very little compared with finding the mistake three months into the job.
The checker should use this same list. Scope clear, every category priced, rates current, contingency explained, cash flow understood. If any item cannot be ticked, that is the conversation to have before submission. There is a longer version of this thinking in the lines that blow your budget, which looks at the costs that were never priced at all.
Then, before the contract is signed, ask yourself one thing: if this job runs exactly as the drawings show, will it make the margin I priced, and will I have the cash to get there? If you cannot answer both halves with confidence, something on the construction budget checklist has not been done. If you would rather have the job priced properly from the start, send your drawings and ask for a fixed fee.