Building Regulations Checklist UK

Most building work in the UK requires Building Regulations approval, including: new builds, extensions, loft conversions, garage conversions, structural alterations, rewiring, new heating systems, replacement windows (unless by FENSA installer), and changes of use. Minor work like painting, tiling, and replacing kitchen units is usually exempt. When in doubt, contact your local Building Control office.

Planning permission controls what you build, where you build it, and how it looks (handled by your local planning authority). Building Regulations control how you build it — ensuring structural safety, fire safety, energy efficiency, and accessibility (handled by Building Control or an Approved Inspector). You may need one, both, or neither depending on the work. They are completely separate legal processes.

Building Control fees vary by local authority and project size. Typical fees for a domestic extension are £200-£600. For a new dwelling, fees range from £500-£1,500. Fees usually have two parts: a plan charge (paid on submission) and an inspection charge (paid on first inspection). Approved Inspectors (private sector) may offer competitive packages. VAT applies to private sector fees but not local authority fees.

Building without approval is a criminal offence. Your local authority can require you to alter or remove non-compliant work, even after completion. They can serve an enforcement notice up to 12 months after completion (no time limit for dangerous work). When selling your property, solicitors will ask for completion certificates and missing certificates can delay or prevent sales. Retrospective regularisation is possible but expensive.

A completion certificate is issued by Building Control or your Approved Inspector when they are satisfied that the work complies with Building Regulations. It is an important legal document that you should keep safely. You will need it when selling the property. If you never received one for past work, you can apply for a regularisation certificate, though this involves inspections and fees.

Yes, almost all loft conversions require Building Regulations approval. Key areas include structural adequacy of the new floor, fire safety (including a protected escape route with fire doors), staircase design, insulation (Part L), head height, ventilation, and electrical safety. Even a simple room-in-roof conversion with no external alterations needs approval.

Following the 2022 Building Regulations update, new build target U-values are: walls 0.18 W/m²K, roof 0.13 W/m²K, floors 0.13 W/m²K, windows 1.2 W/m²K. For extensions and renovations of existing buildings, the targets are less stringent: walls 0.28, roof 0.16, floor 0.22, windows 1.4 W/m²K. These represent the Future Homes Standard interim uplift and further tightening is expected in 2025.

Yes. Scotland has its own Building Standards system governed by the Building (Scotland) Act 2003. Instead of Approved Documents A-S, Scotland uses sections 1-7 of the Technical Handbooks. While the principles are similar, specific requirements differ — for example, Scotland requires CO alarms in all homes and has different energy standards. A building warrant is required before starting work.

An Approved Inspector (AI) is a private-sector alternative to your local authority Building Control team. AIs are registered with CICAIR (Construction Industry Council Approved Inspector Register). They perform the same plan checking and site inspections but may offer faster response times and a more flexible service. The fees are comparable to local authority charges. You can choose either route.

Yes, replacement windows must comply with Building Regulations (Part L for energy efficiency, Part K for safety glazing, Part N for ventilation, and Part Q for security). The easiest route is to use a FENSA-registered installer, who will self-certify the work and notify Building Control on your behalf. If you use a non-registered installer, you must apply to Building Control directly, which adds cost and time.