Free vs Paid Quote Checking - Is It Worth Paying For?

You've got a builder's quote sitting on your kitchen table. The number at the bottom makes you nervous. You want someone - anyone - to tell you whether it's fair.

But how much should checking a quote actually cost? Can you do it yourself? And if you pay for help, what are you actually getting?

Let's break it down honestly.

What you can do for free

There's plenty you can check without spending a penny. Free doesn't mean useless - it just means you're doing the legwork yourself.

Online cost calculators are a decent starting point. Sites like Checkatrade, Household Quotes, and ReallyMoving let you punch in basic project details and get a rough cost range. They won't tell you whether your quote is right, but they'll tell you if you're in the right postcode.

Blog guides and checklists - including the ones on this site - walk you through what a quote should contain. Our guide on what a builder's quote should include covers every section you should expect to see. Follow it line by line and you'll catch the obvious gaps.

Getting multiple quotes is free and surprisingly powerful. Three quotes for the same job show you the market price. If two builders come in at £45,000 and the third says £68,000, you know something's off without needing any tools at all.

Asking around still works. Friends, family, neighbours who've done similar work can tell you roughly what they paid. It's not scientific, but it's a useful sanity check.

Trade price lists are publicly available for most materials. Screwfix, Toolstation, and manufacturer websites let you check whether the materials in your quote are priced sensibly.

All of this is free. All of it helps.

Where free falls short

Here's the problem with doing it yourself: you don't know what you don't know.

A cost calculator can tell you a kitchen extension should cost £40,000–£60,000. But it can't tell you that your quote doesn't mention building regulations fees, or that the drainage route described in the scope won't work without a pumped system, or that "decoration" means primer only - not a finished room.

Missing items are invisible if you didn't know they should be there. A homeowner who's never done an extension won't know that party wall agreements cost £700–£1,500 per neighbour, or that a steel beam needs an engineer's calculation, or that the builder's assumed you're arranging scaffolding yourself.

These gaps are where the real money hides. And they're almost impossible to spot using free tools alone.

Time is a factor too. Properly checking a £50,000 quote against benchmarks, verifying every line item, and researching materials takes hours. If you enjoy that kind of research, crack on. If you'd rather spend a Saturday doing literally anything else, it's worth knowing what the paid options look like.

Free tools also can't compare scope. They'll tell you whether £50,000 sounds right for an extension. They won't tell you that Builder A has included underfloor heating and Builder B hasn't - which explains the £8,000 price difference.

Paid options: what's out there

If you decide the free route isn't enough, there are three main options. They cost very different amounts and do very different things.

AI quote-checking tools - around £10 per project

Tools like MyBuildAlly let you upload your actual quote and get it analysed against benchmark data. The AI reads the document, identifies line items, checks prices against regional averages, and flags anything that looks unusual - missing scope, price outliers, vague descriptions.

It's fast (minutes, not days) and cheap. But it's software, not a human expert. It works well for spotting common issues and giving you a structured second opinion. It won't visit your site or assess the physical condition of your property.

Best for: Quick sense-checks, comparing multiple quotes, spotting obvious gaps and pricing anomalies.

Quantity surveyor - £500–£1,500 per review

A qualified QS will go through your quote with a fine-tooth comb. They'll check every measurement, every rate, every specification. They carry professional indemnity insurance, and their opinion carries weight if you end up in a dispute.

For a large project, a QS review is money well spent. But at £500+ per review, it's not practical for every quote on every project. And finding a good residential QS who'll take on a single domestic job can be tricky - many focus on commercial work.

Best for: Projects over £100,000, complex builds, anything where you need a professional opinion that carries legal weight.

Building consultant - £200–£500 per visit

A building consultant or chartered surveyor can visit your site, review the quote in context, and give you specific advice about your property. They'll spot things that no online tool can - like whether the builder's assumed standard foundations when your soil type needs piles.

They're more expensive than AI tools but cheaper than a full QS review. They're especially useful when you've got a specific concern that needs site-specific knowledge.

Best for: Complex renovations, older properties with potential hidden issues, situations where you need someone to physically inspect the site.

What £10 per project actually gets you

Let's be straight about what an AI quote-checking tool does and doesn't do. You can check current pricing on our pricing page.

What it does well:

• Reads your actual quote and identifies every line item
• Compares prices against regional benchmark data
• Flags items that seem high or suspiciously low
• Spots missing scope - things that should be in the quote but aren't
• Highlights vague descriptions that could lead to disputes
• Gives you a structured report you can use when talking to your builder - see a sample report

What it doesn't do:

• Visit your site
• Assess physical conditions (soil type, structural integrity, services)
• Provide a professional opinion that carries legal weight in disputes
• Replace a quantity surveyor for very large or complex projects
• Guarantee that a quote is fair - it flags concerns for you to investigate

It's a second pair of eyes, not a replacement for professional advice. For most homeowners doing standard work - a kitchen, bathroom, extension, loft conversion - it catches the things that matter most. For a £200,000 listed building renovation, you probably need a QS as well.

When free is good enough

Honestly? For plenty of projects, free is fine.

Small jobs under £5,000 - a new bathroom, a driveway, some fencing - usually don't need paid analysis. Get three quotes, follow a checklist, and you'll spot any problems. Our guide on how to read a builder's quote covers everything you need.

Repeat work you've done before - if you had a bathroom done last year and now you're doing another one, you already know roughly what it should cost and what should be included. Your experience is the best checking tool there is.

Simple, well-defined scope - if the job is "replace 20 metres of fencing with 6ft close-board panels," there's not much to get wrong. The price is the price.

When paid is worth it

The calculus changes on bigger projects.

Your first extension or loft conversion - you've never done this before. You don't know what you don't know. A checking service catches the gaps your inexperience creates. Missing a £3,000 item costs a lot more than £10 per project.

Projects over £10,000 - the stakes are higher, the scope is more complex, and the potential cost of getting it wrong grows with every zero on the quote. Even a 5% saving identified by a checking tool pays for itself many times over.

Multiple quotes to compare - when you've got three quotes in different formats with different inclusions, normalising them into a like-for-like comparison is exactly what analysis tools are built for.

Unfamiliar trades - if you're getting a quote from a roofer, a structural engineer, and a drainage specialist all on the same project, you can't be an expert in all of them. A tool that checks pricing across trades fills that knowledge gap.

Something feels off but you can't explain why - sometimes a quote just doesn't sit right. You can't point to a specific problem, but something nags at you. Running it through an analysis tool either confirms your instinct or puts your mind at rest. Both are valuable.

The bottom line

Free checking is genuinely useful for simple projects. Follow a good checklist, get multiple quotes, and you'll catch most of the obvious problems.

But the things that cost homeowners real money aren't the obvious problems. They're the subtle ones - the scope gap you didn't notice, the specification that sounds fine but isn't, the exclusion buried on page three that adds £4,000 to the final bill.

For a tenner per project, a checking tool catches most of those. For £500+, a quantity surveyor catches all of them. The right choice depends on your project, your budget, and how confident you feel doing it yourself.

If in doubt, start with a free estimate to benchmark your project costs. Then decide whether you need more help from there.

Get started with MyBuildAlly →