10 Ways to Compare Building Quotations Properly Before You Choose a Contractor
Receiving three building quotations does not necessarily mean you have three prices for the same job.
One contractor may have included waste removal, protection, making good and project management. Another may have excluded them. One may have made realistic allowances for plumbing and electrical work, while another may have inserted provisional figures that will almost certainly change later.
This is why simply comparing the totals at the bottom of each quotation can be misleading.
For a refurbishment, extension or renovation project, the important question is not just “Which contractor is cheapest?” It is “What exactly am I getting for this price, and how much uncertainty remains?”
Here are ten practical ways to compare quotations properly before appointing a contractor.
1. Make Sure Every Contractor Has Priced the Same Scope
A quotation is only useful if the contractors have been given broadly the same information.
If Contractor A has priced from detailed drawings and a written scope, while Contractor B has priced after a twenty-minute site visit and a few photographs, their figures are not directly comparable.
Before comparing prices, establish what information each contractor actually used.
Ideally, this should include drawings, specifications, structural information where relevant, a clear schedule of works and agreed assumptions about finishes.
Where information is missing, contractors have to make assumptions. Different assumptions produce different prices.
A detailed quotation from a detailed scope gives you a much stronger starting point than a low figure based on incomplete information.
2. Compare What Is Included, Not Just the Final Total
Two quotations can be £20,000 apart while actually pricing very similar work.
The difference may simply be that one contractor has included items the other has omitted.
Look carefully at the individual sections of each quotation.
For example:
- Site protection and temporary works
- Skips and waste removal
- Scaffolding
- Plumbing and electrical alterations
- Making good
- Decorating
- Building Control attendance
- Final cleaning
- Project management and supervision
If these items appear in one quotation but not another, the bottom-line comparison tells you very little. A cheaper quotation can become significantly more expensive once omitted works are added later.
3. Identify Provisional Sums and Allowances
Allowances are normal in construction, particularly where the final specification has not yet been selected. The problem arises when a quotation contains large allowances that look like fixed prices.
For example, a contractor may allow £5,000 for a kitchen installation but the eventual requirement may cost £9,000. The original quotation has not technically increased because the £5,000 was only an allowance. Check which figures are genuinely fixed and which are provisional.
Pay particular attention to allowances for kitchens, bathrooms, sanitaryware, tiles, flooring, structural work, electrical upgrades and specialist finishes. The more provisional sums a quotation contains, the less certainty you have over the eventual project cost.
4. Check the Exclusions Carefully
The exclusions section can sometimes tell you more than the inclusions. A quotation might appear competitive because several expensive responsibilities have simply been excluded.
Common exclusions include structural engineering, Building Control fees, asbestos surveys, specialist surveys, utility upgrades, decorating, floor preparation or unforeseen repairs.
An exclusion is not necessarily a problem. Contractors cannot reasonably price things they cannot see or control. What matters is understanding the exclusion before signing the contract.
You can then make a realistic allowance elsewhere in your overall project budget rather than discovering the cost halfway through construction.
5. Look at the Level of Detail
The quality of a quotation often gives you an early indication of how the contractor approaches project management. A one-page quotation saying “full refurbishment – £85,000” gives you very little protection if there is later a disagreement about what was included.
A more structured quotation should break the project into sensible work packages.
That does not necessarily mean hundreds of individual rates. For a homeowner, excessive detail can become just as confusing as insufficient detail. The aim is clarity.
You should be able to understand what the contractor intends to do, what materials or standards have been assumed and where additional costs could arise.
6. Compare the Programme as Well as the Price
Price is only one part of a contractor's offer. Suppose one contractor prices your project at £100,000 over sixteen weeks, while another offers £94,000 but expects the project to take twenty-four weeks.
Depending on your circumstances, the apparently cheaper option may cost more overall. You may have additional rent, mortgage overlap, storage costs, temporary accommodation or lost rental income.
Ask each contractor for an indicative programme and proposed start date.
You should also understand how they intend to resource the project. A realistic programme with properly sequenced trades is generally more valuable than an ambitious completion date that cannot be supported.
7. Separate Genuine Savings From Missing Work
There are perfectly legitimate reasons one contractor may be cheaper than another. They may have lower overheads, stronger supplier relationships, their own labour force or a more efficient construction method. But large differences deserve investigation.
If one quotation is dramatically below the others, ask why.
Compare:
- Labour assumptions
- Material specifications
- Quantities
- Preliminaries
- Trade packages
- Programme duration
- Provisional sums
- Excluded works
A saving created by a better construction method is valuable. A saving created because something necessary has been forgotten is not.
8. Understand How Variations Will Be Dealt With
Even a well-planned refurbishment can change. Walls are opened, existing services are exposed and clients sometimes alter finishes or layouts after work begins.
Before appointing a contractor, understand how variations will be priced and approved. Ideally, additional work should be agreed before it proceeds wherever practical.
You should know whether the contractor uses agreed rates, separate quotations, time-and-material calculations or another method. A clear variation procedure protects both parties and avoids the uncomfortable situation where additional costs appear at the end of the project without proper discussion.
9. Assess the Contractor Behind the Number
A quotation is part of the decision, not the entire decision.
You are also appointing the organisation responsible for coordinating trades, protecting your property, managing problems and delivering the finished work. Consider how the contractor has handled the enquiry so far.
Have they asked sensible questions? Have they identified missing information? Have they explained risks rather than simply saying yes to everything? Good pre-construction communication matters because refurbishment projects involve hundreds of small decisions.
The cheapest contractor is poor value if the project becomes disorganised, delayed or filled with arguments about scope.
10. Compare the Likely Final Cost, Not the Starting Price
The most useful comparison is the likely final project cost.Take each quotation and adjust it mentally or preferably in a simple comparison schedule — for obvious omissions, provisional sums and foreseeable extras.
A £90,000 quotation with £15,000 of likely additions may offer less cost certainty than a £100,000 quotation that includes almost everything. This is where proper cost planning becomes valuable.
The objective is not necessarily to eliminate every unknown. That is rarely possible when working with existing buildings. The objective is to identify those unknowns before work starts and allocate realistic money against them.
The Best Building Quotation Is Usually the Clearest One
A good quotation should allow you to understand what is being built, what is included, what is excluded and where the financial risks sit.
That is far more useful than simply receiving the lowest number.
When comparing contractors, look for clarity, realistic allowances, sensible programming and evidence that the contractor has properly understood the project.
A slightly higher quotation with fewer assumptions can ultimately provide far better value than a low starting price followed by months of additional charges.
Planning a Refurbishment in London?
Bayocorp delivers refurbishment, renovation, fit-out, extension and interior construction projects across London and the South East, with cost planning and project management built into the way we approach the work.
If you already have drawings or quotations and want to understand the likely scope, cost and practical delivery of your project, send Bayocorp the details and we can review the best next step.