Why the Cheapest Building Quote Can Cost More
A low price is only good value if it covers the same job. Here is where the difference usually sits, and how to check before you accept.
The short version
The lowest figure is the start of the cost, not the whole of it. The quote that is clearest about what it covers is the one you can plan around.
A building quote is a price for a described piece of work. When two quotes describe different work, their prices can't be compared, even if the headline job sounds the same. A low quote often turns out to be low because it covers less: scaffolding left out, a smaller allowance for things nobody can see yet, cheaper materials, or a shorter warranty.
None of that makes a low quote wrong. Some contractors genuinely cost less to run, and some price keenly when they have a gap in the diary. The point is to work out which kind of low price you are looking at before you accept it, not after the extras arrive.
This guide covers where the gaps usually sit, how to put quotes on the same footing, and which questions tell you whether a cheaper price is solid. For the wider picture on quotes and payments, start with our homeowner's guide to building quotes and payments.
The principle
A price only means something next to its scope
Every quote answers two questions: what will be done, and what it will cost. Homeowners naturally look at the second answer first, because it is a single number. The first answer is where the real comparison happens.
Imagine three quotes for the same roof. One includes scaffolding, removal of the old materials, and a clearly stated allowance for replacing any rotten timber found once the old covering is off. One includes scaffolding but says nothing about timber or waste. The third is a single line with a total. The third will often be the cheapest, and it tells you the least about what you are buying.
When the work starts, whatever the cheaper quotes left unsaid still has to be dealt with. The scaffold still has to go up. The waste still has to leave site. The timber still has to be replaced if it is rotten. If those things were not in the price, they become extras, and extras are priced after you have committed, when you are in a far weaker position to compare.
That is the whole mechanism behind the cheapest quote costing more. It is rarely a trick. More often it is a quote written quickly, with the uncertain parts left for later. Our guide to what a building quote should include sets out what a complete one looks like.
Where the gap sits
Six places a low price can come back
When a quote is well below the others, the difference is usually in one or more of these.
Items left out
Scaffolding, access equipment, skips, waste removal, making good after the work and cleaning up are easy to leave off a quote. Our answers on whether scaffolding should be on the quote and whether a quote includes waste removal cover the two most common.
Allowances set low
Where part of the work can't be priced until it is uncovered, a quote may include an allowance for it. A small allowance makes the total look smaller, but the final cost will be whatever the work actually needs.
A different specification
Materials vary in quality, lifespan and price. Two quotes can both say the same thing in general terms while pricing quite different products. If the quote doesn't name them, you can't tell.
Optimistic assumptions
A quote may assume the structure underneath is sound, or that access is easy, without saying so. If the assumption turns out to be wrong, the cost of dealing with it falls outside the price.
A shorter warranty
A workmanship warranty has value. A quote that offers a longer one is offering more, and it is fair to weigh that when one price is higher than another.
A price that doesn't cover the job
Occasionally a price is simply too low for the work. A contractor who has underpriced a job has a harder time finishing it well, and that can show up as delays, pressure for extra payments or a rushed finish.
A low quote is not automatically a bad one. A small firm with low overheads, a contractor based nearby, or one with a gap in their schedule can all price competitively and do excellent work. The aim is not to avoid the cheapest quote. It is to make sure it covers the same job before you compare it.
Putting quotes side by side
How to check a low quote against the rest
Half an hour with the quotes and a pen will usually show you where the difference lies.
List what each quote includes
Write down every item each contractor has priced, line by line. Gaps show up quickly when the lists sit next to each other.
List what each quote excludes
Some quotes state exclusions. Others leave them unsaid. Anything that appears on one quote and not another is a question to ask.
Pick out the allowances
Look for any figure described as provisional, an allowance or subject to inspection. Compare them, and ask how each contractor arrived at theirs. Our guide to provisional sums explains how they work.
Compare the materials
Ask each contractor to name the main products they intend to use. If one has priced a cheaper option, you can decide whether that suits you, but at least you'll know.
Ask how extras are priced
Ask each contractor how they would price work that turns out to be needed once the job starts. A clear answer now saves a difficult conversation later.
Compare the adjusted totals
Add the missing items to the quotes that left them out, using the other quotes as a guide. That adjusted figure is the one to compare. Our guide to comparing building quotes goes through the full method.
Reading the signs
What a well-founded low price looks like
These are general signs, not rules. A good contractor can tick the right-hand column by accident, and the reverse is true too.
Usually a solid price
- Written, itemised and specific about the work
- Names the main materials
- States what is excluded
- Explains any allowances and how they'll be settled
- Sets out the warranty and payment terms
- The contractor answers questions about it clearly
Worth asking more about
- A single total with no breakdown
- Materials described only in general terms
- Silent on scaffolding, waste or making good
- Well below every other quote with no clear reason
- Vague about how extra work would be charged
- Pressure to accept quickly
The costs off the page
What a quote can't show you
Some of the cost of a building job never appears on a quote. It is worth thinking about when you weigh one price against another.
Your time. A job that runs smoothly takes little of your time. One that needs regular chasing, repeated conversations about extras and a long list of snags at the end takes a great deal of it. That time has a cost, even if nobody invoices you for it.
The length of the job. Work that overruns means longer with scaffolding up, rooms out of use or a household working around the job. A contractor with a realistic price has less reason to stretch the job or leave it part-way to earn elsewhere.
Putting things right. Where work isn't right first time, it has to be revisited. The warranty should cover defective workmanship, but even a warranty repair means more disruption, and it depends on the contractor still being around and willing to return.
The final bill. This is the only figure that matters in the end. A quote that looked higher but covered everything can finish below one that looked lower and grew along the way. Our guide to variations and extra costs explains how that growth usually happens.
Talking to contractors
Asking the right questions about price
If the cheapest quote is otherwise the one you prefer, the most useful thing you can do is ask the contractor to confirm, in writing, the items the other quotes included. "Does your price include scaffolding, removal of waste and making good?" is a fair question, and a straightforward answer is a good sign.
If the higher quote is the one you prefer, it is reasonable to ask whether there is any flexibility. Be fair about it: showing a contractor a lower figure that covers less work, and asking them to match it, is not comparing like with like. Our answer on whether you can negotiate a building quote covers how to do it well.
It is also worth asking why the quotes differ. Contractors are often candid about it. One may explain that they have allowed for replacing timber because in their experience it is usually needed. Another may say they priced the job assuming it isn't. Both answers are useful, and neither is necessarily wrong. Our answer on why building quotes are so different covers the usual reasons.
Finally, look at the contractor as well as the price. Who will carry out the work, what insurance do they hold, what warranty do they give, and can you see work they have done before? Our guide to choosing a contractor covers that side, including whether a very cheap quote is a bad sign.
How Mortaro approaches it
A clear quotation, priced to be comparable
Mortaro coordinates domestic building work, carried out by an independent main contractor from our network. After the site visit, your contractor prices the job at trade rates and we prepare it as a clear written quotation on our template, naming them as your main contractor. It is free, carries no obligation and is valid for 30 days, which gives you time to compare it properly.
Because contractors in our network price at trade rates, your quotation is comparable to going to a contractor directly, with the coordination included. We won't claim to be the cheapest. Anyone can be undercut, and this page explains why the lowest figure isn't always the lowest cost.
If anything on your quotation is unclear, ask us and we'll get the answer from your contractor. How quotations work sets out the process in full.
Straight answers
Questions about cheap quotes
Should I always avoid the cheapest quote?
No. The cheapest quote can be the best one. Check that it covers the same work, materials and extras as the others, and that you are comfortable with the contractor. Our answer on whether you should accept the cheapest quote goes into more detail.
Why would a contractor quote low and then add extras?
Usually because the uncertain parts of the job were left out of the price rather than estimated. Sometimes it is simply a quote written quickly. Asking every contractor the same questions about what is included brings this to the surface before you commit.
How far below the others is too far?
There is no set figure. A modest gap is common. A price far below every other quote, with no clear reason, is worth asking about. Ask the contractor what they have included and how they would price anything extra.
Is the most expensive quote the safest choice?
Not necessarily. A high price can reflect a thorough scope, a longer warranty or higher overheads, but it is no promise of better work. Compare scope, specification and warranty, and check the contractor, whatever the price.
Start here
Tell us about the work you have in mind
We will confirm we cover your postcode, arrange a site visit with a contractor from our network and send you a written quotation. No charge, no obligation.