Building Control vs Approved Inspectors: Which Route to Choose
You can use your local council's building control or a private approved inspector. Here's how they compare on cost, speed, and what to watch out for.
Your builder says they'll "sort out building control" and mentions a company you've never heard of. They seem keen on this particular inspector. Should you just go along with it, or use the council instead?
In short: You have two routes for building regulations approval: your local council's building control team, or a private approved inspector (now called registered building control approvers). Both do the same job - checking that your building work complies with the regulations. Council building control is independent by default. Private inspectors may be faster and more flexible, but you should understand the relationship before signing up.
Both routes lead to the same destination: a completion certificate confirming your work is building regulations compliant. Without that certificate, you'll have problems when you sell the house.
What building control actually does
Building control is separate from planning permission. Planning deals with what you build and how it looks. Building control deals with how it's built - structural safety, fire protection, insulation, drainage, ventilation, and accessibility.
Building control officers (whether council or private) carry out inspections at key stages of construction:
- Plan check - reviewing your drawings and specifications before work starts to check they comply with the Building Regulations (Approved Documents A through S)
- Foundation inspection - checking the trench depth, width, and ground conditions before concrete is poured
- Damp-proof course (DPC) - checking the DPC is correctly installed before walls are built above it
- Oversite - inspecting the ground floor slab or beam-and-block construction
- Drainage - testing drains before they're backfilled
- Structural steel - checking steels are correctly sized and positioned
- Pre-plaster - inspecting insulation, fire stopping, ventilation, and hidden services before they're covered up
- Final inspection - a comprehensive check of the finished building
Not every project requires every inspection. Your building control body will tell you which stages need sign-off for your specific project.
For details on what the regulations require at each stage, see our guide on building regulations key measurements.
Council building control
Every local authority in England and Wales has a building control department. They've been doing this for decades, and it's their bread and butter.
Advantages:
- Independence - council officers have no commercial relationship with your builder. Their only interest is compliance.
- Local knowledge - they know the local ground conditions, drainage requirements, and any area-specific issues (flood risk, conservation areas, mining subsidence).
- Enforcement power - if work doesn't comply, the council can serve enforcement notices and, in extreme cases, require demolition. Private inspectors can't do this - they must refer non-compliant work back to the council.
- Consistency - you know what you're getting. Council building control follows a standard process.
Disadvantages:
- Speed - council departments can be slow, particularly in busy areas. Getting a plan check back might take 3–5 weeks. Booking an inspection might require several days' notice.
- Flexibility - council officers work standard hours. If your builder finishes the foundations on a Friday afternoon and needs a sign-off before pouring concrete on Monday, a council officer might not be available.
- Communication - some council departments are better than others. In under-resourced authorities, you might find it hard to get through to your assigned officer.
Cost: Council building control fees are set by each local authority and published on their website. Typical ranges:
| Project type | Plan check fee | Inspection fee | Total |
|---|---|---|---|
| Single-storey extension | £150–£250 | £250–£450 | £400–£700 |
| Two-storey extension | £200–£300 | £350–£550 | £550–£850 |
| Loft conversion | £200–£300 | £300–£500 | £500–£800 |
| Full house renovation | £250–£400 | £400–£700 | £650–£1,100 |
Fees are usually split into a plan check fee (paid when you submit drawings) and an inspection fee (paid when the first inspection is requested).
Private approved inspectors
Since 1985, private companies have been able to carry out building control functions. These are now formally called registered building control approvers under the Building Safety Act 2022, though most people still call them approved inspectors.
Private inspectors are registered with the Building Safety Regulator (part of the HSE) and must meet professional and insurance standards.
Advantages:
- Speed - private inspectors are typically faster. Plan checks might come back in 1–2 weeks. Inspections can often be booked at shorter notice.
- Flexibility - some offer evening or weekend inspections. They're more likely to accommodate your builder's schedule.
- Relationship - your builder may have a working relationship with a particular inspector, which can make the process smoother. The inspector knows the builder's standards, and the builder knows what the inspector expects.
- Package deals - some inspectors offer fixed-price packages covering all inspections for a project, which can simplify budgeting.
- Single point of contact - you'll typically deal with one named inspector throughout the project, rather than whoever is on duty at the council.
Disadvantages:
- Potential conflict of interest - this is the main concern. A private inspector paid by the builder (or recommended by the builder) has a commercial incentive to maintain that relationship. This doesn't mean they'll ignore defects, but the dynamic is different from a council officer who has no financial stake.
- No enforcement power - if a private inspector finds non-compliant work and the builder won't fix it, the inspector must refer the case to the local authority. They can't serve enforcement notices themselves.
- Variable quality - most private inspectors are excellent. Some are not. The sector has had quality issues, which led to the reforms in the Building Safety Act 2022.
- If they go bust - if your approved inspector ceases trading before your project is complete, the project reverts to the local authority. This creates delays and additional costs. It's rare, but it happens.
Cost: Similar to council fees, though private inspectors have more pricing flexibility:
| Project type | Typical cost |
|---|---|
| Single-storey extension | £400–£700 |
| Two-storey extension | £550–£900 |
| Loft conversion | £450–£800 |
| New-build house | £800–£1,500 |
Some inspectors quote lower fees to win work, then charge extra for additional inspections or re-inspections. Check what's included in the quoted price.
How to choose
Use council building control if:
- You want maximum independence
- You're not in a rush and the council response times are acceptable
- Your builder doesn't have a strong preference
- You're unsure about the quality of available private inspectors
- The project involves higher-risk work (anything structural, fire safety critical, or near boundaries)
Use a private approved inspector if:
- Your builder has a recommendation and you trust the relationship
- Speed matters - you need faster plan checks and flexible inspection schedules
- The project is relatively straightforward (standard extension, loft conversion)
- The inspector is well-established with a good track record
Questions to ask a private inspector:
- Are you registered with the Building Safety Regulator?
- What's included in your fee? How many inspections? Are re-inspections extra?
- Who will carry out the inspections? Will it be the same person throughout?
- What's your relationship with the builder? How many projects have you worked on together?
- What happens if you find non-compliant work? What's your process?
Questions to ask your builder:
- Why do you prefer this particular inspector?
- Would you be happy to use council building control instead?
- How many projects have you done with this inspector?
A builder who insists on a specific inspector and won't consider the council alternative should explain why. There might be a perfectly good reason - the council is slow, the inspector knows their work, the package is cheaper. But you should understand the reasoning.
The completion certificate
Whichever route you choose, the end product is the same: a completion certificate confirming that the work complies with the Building Regulations.
This certificate is important. Without it:
- Your home insurance may not cover the new work
- You'll face problems when you sell the property - solicitors check for building regulations certificates
- The local authority can take enforcement action (for up to two years after completion, or longer in some cases)
- A mortgage lender may refuse to lend against the property
If your builder's quote doesn't mention building control or building regulations, that's a red flag. Either the work doesn't require building regulations approval (possible for very minor work), or the builder is planning to skip it. See our guide on what to do when your quote is missing building regs for more on this.
Keep the completion certificate with your property deeds. You'll need it eventually.
The Building Safety Act 2022: what changed
The Building Safety Act 2022, introduced in response to the Grenfell Tower tragedy, brought significant changes to building control:
- Building Safety Regulator - the HSE now oversees all building control in England, including registration of private inspectors
- Higher-risk buildings - buildings over 18 metres (7+ storeys) must use the Building Safety Regulator directly, not council or private inspectors. This mainly affects commercial and residential developments, not individual homeowner projects
- Competence requirements - all building control professionals must demonstrate competence and be registered
- Greater accountability - private inspectors face stricter oversight and reporting requirements
For standard residential projects (extensions, loft conversions, renovations), the practical impact is limited. The main change is that private inspectors are now more tightly regulated, which should improve consistency.
Got a quote? Check whether building control is covered
Building control fees are sometimes included in a builder's quote and sometimes not. If they're not listed, add £400–£1,200 to your budget depending on project size. Upload your quote to MyBuildAlly and we'll check whether building regulations costs are accounted for, and flag anything that looks like it might need approval but isn't mentioned.
Sources
- GOV.UK: Building regulations approval - overview of the building control process
- Building Safety Regulator - registration and oversight of building control
- Building Safety Act 2022 - the legislation reforming building safety and control
- LABC (Local Authority Building Control) - find your local council's building control team
- GOV.UK: Approved Documents - the technical guidance for building regulations compliance