When Do I Need Building Control Sign-Off? A Tradesperson's Guide

Quick Answer: Most building work in England and Wales must comply with Building Regulations, but not all of it requires a formal building control application. If you are a member of a competent person scheme (e.g. Gas Safe, FENSA, NAPIT, NICEIC), you can self-certify many common jobs without involving building control directly. For everything else -- extensions, structural alterations, new drainage, loft conversions -- you need either a building notice or a full plans application before work starts.

Summary

Building Regulations set minimum standards for the design, construction, and alteration of buildings in England and Wales, governed by the Building Act 1984 and the Building Regulations 2010. Building control is the process by which compliance is checked, either by a local authority building control (LABC) team or, since April 2024, a registered building control approver (private sector). Not every job triggers a building control application: some work is exempt under Schedule 2 of the Regulations, and certain types of work can be self-certified through competent person schemes without a separate application. However, if controlled work is carried out without approval and without self-certification, the homeowner risks enforcement action, difficulty selling the property, and costly retrospective regularisation. As a tradesperson, knowing which route applies to each job lets you advise customers confidently and avoid compliance problems down the line.

Key Facts

Quick Reference: Does This Work Need Building Control?

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Type of Work Building Control Needed? Self-Certification Route?
Boiler replacement (gas) Yes Gas Safe Register (competent person)
Boiler replacement (oil) Yes OFTEC (competent person)
Central heating system install/replacement Yes Gas Safe / OFTEC / HETAS (competent person)
Bathroom refit (like-for-like) No (unless drainage or electrics change) N/A
New bathroom in a new location Yes Electrical element via Part P scheme
Kitchen refit (like-for-like) No (unless structural, drainage, or electrics change) N/A
Kitchen refit with wall removal Yes (structural + possibly electrical) Electrical element via Part P scheme
Replacement windows and external doors Yes FENSA / CERTASS / other glazing scheme
New windows in a new opening Yes (full application -- not self-certifiable) No
Rewire / new consumer unit Yes (notifiable under Part P) NICEIC / NAPIT / ELECSA (competent person)
New circuit (e.g. cooker, EV charger) Yes (notifiable under Part P) NICEIC / NAPIT / ELECSA (competent person)
Adding a socket to an existing circuit No (non-notifiable, outside special locations) N/A
Electrical work in a bathroom zone Yes (notifiable under Part P) NICEIC / NAPIT / ELECSA (competent person)
House extension Yes No
Loft conversion Yes No
Garage conversion Yes No
Removing a load-bearing wall Yes No
Removing a non-load-bearing wall Generally no N/A
Chimney breast / stack removal Yes No
Underpinning Yes No
Roof re-covering (same materials) No N/A
Roof re-covering (different materials/structure) Yes No
Solar panel installation Yes (electrical element) MCS / NAPIT / NICEIC (competent person for electrical)
Heat pump installation Yes MCS-certified installer (competent person)
Wood-burning stove / flue installation Yes HETAS (competent person)
New drainage or soil pipe run Yes No
Porch (under 30 m², ground level, no new heating) No (exempt) N/A
Conservatory (under 30 m², thermally separated) No (exempt) N/A
Detached outbuilding (under 30 m², not sleeping) No (exempt) N/A
Structural timber treatment (damp/rot) No N/A
Replacing a flat roof Yes (thermal element upgrade required) No
Rendering / external wall insulation Yes (thermal element) No

Notes on the table:

Detailed Guidance

Do I need building control for a bathroom refit?

A straightforward bathroom refit -- replacing the bath, basin, WC, and tiles in the same positions -- does not normally require building control approval. The tipping points are:

Bottom line for customers: "If we're swapping out your existing suite in the same layout, no building control needed. If we're moving the WC, adding a shower where there wasn't one, or doing any rewiring, we'll need sign-off."

Do I need building control for a boiler replacement?

Yes, a boiler replacement is controlled work under the Building Regulations (primarily Part J -- combustion appliances, and Part L -- energy efficiency). However, most tradespeople handle this through self-certification:

If the installer is not a member of a competent person scheme, the homeowner must submit a building notice to the local authority before work starts and pay the relevant fee. A building control inspector will then need to inspect the installation.

When a full plans application is needed: Rarely for a boiler swap. It may be required if the flue route involves significant structural changes, or if the boiler is being relocated to a position that requires new gas pipework routing through unusual locations.

Key compliance points: The new boiler must meet current Part L efficiency requirements (typically 92%+ ErP rating). The flue position must meet the distances in Approved Document J (clearances from openable windows, boundaries, and air bricks).

Do I need building control for a kitchen refit?

A straightforward kitchen refit -- new units, worktops, and appliances in the same layout -- does not require building control approval. Building control is triggered when:

What's the difference between a building notice and a full plans application?

These are the two routes for submitting a building control application to your local authority.

Building Notice

Full Plans Application

Costs: The total fees charged by the local authority are typically the same for both routes. However, a building notice avoids the cost of preparing detailed plans upfront, while a full plans application avoids the risk of costly rework if something is not right. Most local authorities publish their fee schedules online. Typical charges range from around 150-400 GBP for small domestic work (e.g. a single structural opening) to 800-1,500+ GBP for extensions and loft conversions.

Private building control (registered building control approvers): Since October 2023, you can also use a registered private-sector building control approver for most domestic work. They set their own fees and often offer a more responsive service. They carry out the same inspections and issue the same completion certificate.

What happens if I do work without building control approval?

This is a serious issue that tradespeople need to understand, both for their own liability and to advise customers properly.

Enforcement: Under Section 36 of the Building Act 1984, the local authority can serve an enforcement notice requiring the removal or alteration of work that contravenes the Regulations. In extreme cases, they can seek a magistrates' court injunction or High Court order for demolition. Prosecution is also possible, though in practice this is rare for domestic work.

Time limit for enforcement: The local authority must take enforcement action within 12 months of the work being completed (Section 36). After 12 months, they cannot require removal, but the work still does not have a compliance certificate.

Selling the property: This is where it most commonly causes problems. When a property is sold, the buyer's solicitor will ask for completion certificates for any building work. Missing certificates can delay or derail a sale. The options are:

  1. Regularisation certificate: Apply to the local authority to have the work assessed retrospectively. Available for work carried out after 11 November 1985. The fee is typically higher than the original application would have been (often 1.5x to 2x). Building control may require you to open up finished work (e.g. expose steels, insulation, drainage) for inspection. If the work does not comply, you must carry out remedial work before a certificate is issued.
  2. Indemnity insurance: A quicker, cheaper option (20-300 GBP) that covers the buyer against the financial risk of the local authority taking enforcement action. This does not confirm the work is safe or compliant -- it only covers the financial loss. Many solicitors accept this for older work, but it is not a substitute for a proper certificate.
  3. Do nothing: The buyer may negotiate a price reduction, or the sale may fall through.

Your liability as a tradesperson: If you carry out controlled work and fail to notify building control (and are not self-certifying through a competent person scheme), you could face enforcement action, reputational damage, and potential civil liability if the work later causes harm.

Frequently Asked Questions

Can I start work before building control approves my plans?

With a building notice, yes -- you can start 48 hours after submitting the notice and fee. With a full plans application, technically you can start before approval, but you do so at your own risk. If the plans are subsequently rejected or conditionally approved, you may need to undo or modify work already completed. Most builders wait for approval on a full plans application before starting.

Do I need building control for a like-for-like repair?

Generally no. Replacing damaged materials with the same or similar materials (e.g. replacing broken roof tiles with matching tiles, repairing a section of render) is maintenance and is not controlled work. However, if you are replacing a thermal element (e.g. re-roofing more than 25% of a roof, or re-rendering more than 25% of a wall), you must upgrade the thermal performance to current Part L standards, and this is controlled work.

What is a completion certificate and why does it matter?

A completion certificate is the formal document issued by building control (either the local authority or a registered building control approver) confirming that the work has been inspected and complies with the Building Regulations. It is the proof that the work was done properly. Solicitors require it when a property is sold. Without it, the homeowner has no official evidence of compliance, which can cause significant problems at the point of sale.

How long does building control take?

For a building notice, there is a 48-hour minimum before you can start. Inspections happen at agreed stages during construction, and a completion certificate is issued after the final inspection. For a full plans application, allow 5 weeks for plan checking (8 weeks if extended). Inspection timescales during construction depend on the local authority's workload -- most aim to inspect within 1-2 working days of being notified.

Do competent person scheme certificates expire?

No. A Building Regulations Compliance Certificate issued through a competent person scheme does not expire. It is a permanent record that the work complied with the Regulations at the time it was carried out. However, the annual Gas Safety Certificate (CP12) for landlords is a separate document and must be renewed every 12 months.

Regulations & Standards