My Quote Doesn't Mention Building Regs - Should I Be Worried?
If your builder's quote doesn't mention building regulations, it might not be dodgy - but you need to ask. Here's what building regs cost and why they matter.
Your builder's quote has landed. You've checked the price, looked at the breakdown, and it seems reasonable. But then someone mentions building regulations and you realise - your quote doesn't say a word about them.
Should you be worried? Not necessarily. But you absolutely need to ask about it before work starts. Here's why.
What are building regulations?
Building regulations are the safety standards that most building work in the UK has to meet. They cover things like structural stability, fire safety, insulation, ventilation, drainage, and electrical safety. Think of them as the minimum rules that ensure your extension won't collapse, catch fire, or freeze in winter.
They're separate from planning permission. Planning permission is about whether you can build. Building regulations are about how you build. You can need one without the other, and most extensions need both.
Building control is the inspection process that checks your work meets the regulations. A building control officer (either from the council or a private approved inspector) visits the site at key stages - foundations, drainage, structural steel, insulation, completion - and signs off each one.
At the end, you get a completion certificate. This is the document that proves your building work was done to standard. It's important. More on that later.
What should your quote say about building regs?
A proper quote should mention building regulations in one of two places:
Included in the quote: The best scenario. The builder has factored in the building control fees and listed them as a line item. Something like: "Building control fees (local authority): £750."
Listed in the exclusions: Also fine. The builder is telling you that building regs fees aren't part of their price and you'll need to arrange and pay for building control separately. That's transparent and honest - you just need to budget for it.
Not mentioned at all: This is the grey area. It doesn't automatically mean the builder is dodgy. Some builders genuinely forget to include it, especially smaller outfits who focus on the physical work and leave the paperwork to the homeowner. But it's a gap you need to close.
For a full list of what should and shouldn't be in a quote, see our guide on what a builder's quote should include.
How much do building regulations cost?
Building control fees vary by project size and local authority, but here's the ballpark for common residential projects:
| Project | Typical building control fee |
|---|---|
| Single-storey extension (up to 40m²) | £500–£800 |
| Double-storey extension | £700–£1,000 |
| Loft conversion | £500–£800 |
| Garage conversion | £400–£600 |
| New kitchen (structural changes) | £400–£600 |
| Full rewire | £300–£500 |
These are local authority fees. You can also use a private approved inspector - an independent company licensed to do building control inspections instead of the council. They often charge similar or slightly lower fees, and some builders prefer them because appointment scheduling tends to be more flexible.
Either way, it's not a huge sum in the context of a £50,000 extension. But it's a cost you need to know about.
What happens if you skip building regulations?
This is the bit that really matters. Skipping building control isn't just a technicality. It can cause serious problems down the road.
Selling your house becomes harder
When you sell your property, your buyer's solicitor will check for building regulations completion certificates for any work done. No certificate? The solicitor flags it. The buyer gets nervous. The sale stalls or falls through.
You can get retrospective building control approval - but it's expensive and disruptive. The building control officer may need to inspect hidden work, which could mean opening up walls or floors. If the work doesn't meet current standards, you'll need to pay for remedial work before they'll sign it off. We're talking thousands of pounds, not hundreds.
Some solicitors will accept indemnity insurance instead of a completion certificate. This is a one-off insurance policy that covers the buyer if the council ever takes enforcement action. It's cheaper than retrospective approval (typically £200–£400), but not all buyers or mortgage lenders will accept it. And it doesn't actually prove the work is safe.
Your home insurance may not cover you
Most home insurance policies require that building work has the relevant approvals. If your extension was built without building control sign-off and something goes wrong - a structural failure, a fire, water damage from poor drainage - your insurer may refuse the claim.
They won't check proactively. But if you make a claim and they investigate, the absence of a completion certificate gives them a reason to decline it.
It's technically illegal
Local authorities can take enforcement action against building work done without building control approval. In practice, this is rare for residential work - councils have bigger fish to fry. But the power exists, and if a neighbour complains or a safety issue is discovered, the council can require you to bring the work up to standard or even demolish it.
Red flags to watch for
A missing mention of building regs isn't always sinister. But combine it with any of these and you should be concerned:
- "We don't need building regs for this." For most extensions, loft conversions, and structural alterations, you absolutely do. There are a few exemptions (small porches, certain outbuildings, like-for-like replacements), but if your project involves structural changes, new electrics, or changes to drainage, building control is required.
- "I'll sort the building regs." Ask what this means specifically. Will they apply for building control? Will they pay the fees? Will they be on site when the inspector visits? Vague promises aren't good enough.
- "The building inspector will just sign it off at the end." Building control isn't a rubber stamp at the end of the job. Inspections happen at key stages throughout the build. If the inspector hasn't seen the foundations before they're covered up, they can't certify them. The builder needs to understand this.
- No mention of building regs, structural engineer, or building control anywhere in the quote. If the quote also doesn't mention a structural engineer's calculations (structural calcs), that's a compounding red flag. Most extensions need both - and a builder who doesn't mention either may not be used to managing the regulatory side of projects.
For more warning signs in quotes, see our post on signs your builder might be overcharging - which covers vague scope, missing exclusions, and other gaps that cost you later.
What to do right now
Step 1: Ask your builder directly
Send them a message: "I noticed the quote doesn't mention building regulations. Can you clarify whether building control fees and inspections are included, or whether I need to arrange those separately?"
That's all it takes. Most builders will come back with a clear answer. If they seem confused by the question, that's a concern.
Step 2: Check what building control you need
For most residential building work, you need to submit either a building notice or a full plans application to your local council (or a private approved inspector):
- Building notice: Simpler and cheaper. You tell the council what you're doing and they inspect as you go. Suitable for most standard extensions and conversions. Costs less, but you don't get pre-approved drawings.
- Full plans application: You submit detailed drawings and the council checks them against the regulations before you start. More upfront work, but gives you certainty that your design complies. Required for some types of work (commercial, complex structures).
You also have a choice between your council's building control team and a private approved inspector. Our guide explains the differences, costs, and when each option makes more sense. Your builder or architect should advise which route is appropriate.
Step 3: Budget for the fees
If building control isn't included in the quote, add £500–£1,000 to your project budget. It's a relatively small cost that saves potentially enormous headaches later.
Step 4: Make sure inspections happen
Building control inspections need to happen at the right stages. Foundations before they're backfilled. Drainage before it's covered. Insulation before it's plastered over. If your builder covers up work before it's been inspected, the building control officer can't sign it off - and you may need to dig it up again.
Ask your builder: "Who's responsible for booking the building control inspections?" If it's them, get it in the contract. If it's you, make sure you know the inspection stages and have the building control officer's contact details. Our guide on checking foundation work covers the most critical inspection stage - the one that happens before concrete is poured and can never be revisited.
Other costs that might be missing too
If building regulations aren't mentioned, it's worth checking for these commonly excluded items as well:
- Structural engineer's design and calculations: £500–£1,500
- Party wall surveyor fees: £700–£1,500 per neighbour
- Scaffolding: £1,200–£3,000
- Skip hire: £280–£400 per skip
- Planning application fee: £258 for householder applications
These can add up to £3,000–£5,000 on top of the quoted price. For a complete reference of the key measurements and standards your project needs to meet, see our building regulations measurements guide. If they're not mentioned - either as included or excluded - you need to ask. And if the builder later tries to charge for them as "extras" mid-project, see our guide on what to do when your builder changes the price after starting.
You can check your quote for these gaps quickly using MyBuildAlly's quote checker. Upload your builder's quote and we'll flag anything that's missing or unclear, including building control fees.
If your builder is asking for a large deposit on top of a quote that's missing key items like building regs, read our post on whether a 50% deposit is normal before you hand over any money.
The bottom line
A quote that doesn't mention building regulations isn't necessarily a red flag. Some builders genuinely leave it to the homeowner. But you need to know about it, budget for it, and make sure it happens.
Building control fees are a small price to pay for the peace of mind that your extension is safe, legal, and won't cause problems when you sell. Don't skip it. Don't let your builder skip it. And don't assume it's included just because it's not excluded.
Ask the question. Get the answer in writing. Move on with confidence.