Building Regulations in the UK: A 2026 Guide to the Approved Documents, Routes and Compliance

What are building regulations?

Building regulations are the national technical standards for the design, construction, and alteration of buildings in England and Wales. The primary statute is the Building Act 1984, and the substantive regulations are the Building Regulations 2010 (SI 2010/2214), as amended.

The regulations are administered by local authorities (through their building control teams) and, alternatively, by registered Approved Inspectors. Building control is a parallel regime to planning permission — they are governed by different statutes, have different decision-makers, and apply to different aspects of building work.

Building regulations apply in England and Wales. Scotland has its own regime under the Building (Scotland) Act 2003 and the Building (Scotland) Regulations, administered by local authority Building Standards teams. Northern Ireland is governed by the Building Regulations (Northern Ireland) Order 1979 as amended. This guide covers the England and Wales regime; the principles are similar in the devolved nations.

The Approved Documents A–S

The technical standards for the building regulations are set out in a series of Approved Documents published by the Department for Levelling Up, Housing and Communities. Each Approved Document covers a specific aspect of building work and is updated periodically.

• Part A — Structure.
• Part B — Fire safety (Volumes 1 and 2: dwellings, and buildings other than dwellings).
• Part C — Site preparation and resistance to contaminants and moisture.
• Part D — Toxic substances.
• Part E — Resistance to the passage of sound.
• Part F — Ventilation.
• Part G — Sanitation (including hot water safety).
• Part H — Drainage and waste disposal.
• Part J — Combustion appliances and fuel storage systems.
• Part K — Protection from falling, impact and collision.
• Part L — Conservation of fuel and power (energy efficiency).
• Part M — Access to and use of buildings.
• Part N — Glazing safety.
• Part O — Overheating.
• Part P — Electrical safety.
• Part Q — Security in dwellings.
• Part R — Physical infrastructure for high-speed electronic communications networks.
• Part S — Infrastructure for the charging of electric vehicles.

The Approved Documents are statutory guidance — they set out one or more ways of complying with the functional requirements of the Building Regulations. It is possible to use alternative methods of compliance, but the Approved Documents remain the practical benchmark for most projects.

When you need building regulations approval

Building regulations approval is required for most physical building work, including:

• New build — every new dwelling, commercial building, or extension over a small size threshold.
• Extensions and alterations — most extensions to an existing building require an application; the size threshold depends on the type of work.
• Loft conversions — almost always require an application because of the structural, fire-safety, and insulation implications.
• Garage conversions — converting an attached garage to habitable space always requires an application.
• Replacement windows and doors — where the structural opening is altered, where the property is in a Conservation Area and the alteration affects the character, or for certain window types in any location.
• Electrical work in certain locations — bathrooms, kitchens, outbuildings, and external work typically require Part P notification.
• Boiler and heating work — most installations and replacements require a Building Regulations application or use of a Competent Person Scheme.
• Structural alterations — removing walls, removing chimneys, underpinning foundations, and similar.

A small amount of work is exempt under Schedule 2 of the Building Regulations 2010. The GOV.UK quick decision tool provides a fast way to confirm whether your work needs approval.

Building regulations vs planning permission

Building regulations and planning permission are two parallel regulatory regimes with different legal bases, different decision-makers, and different application types:

• Planning permission — governed by the Town and Country Planning Act 1990. Run by Local Planning Authorities (LPAs). Concerned with the use of land and buildings, the appearance of development, and its impact on neighbours and the environment.
• Building regulations — governed by the Building Act 1984. Run by Building Control bodies. Concerned with structural safety, fire safety, energy efficiency, ventilation, sanitation, and accessibility.

A single project can require:

• Planning permission only — e.g. a change of use that does not affect the building fabric.
• Building regulations approval only — e.g. certain internal alterations that are Permitted Development under planning but still affect structure or fire safety.
• Both — the most common case, e.g. a new extension typically needs both.
• Neither — some work is exempt from both regimes.

The two regimes are independent and neither overrides the other. A project that has planning permission but no building regulations approval is non-compliant; a project that has building regulations approval but no planning permission is also non-compliant.

The two application routes

For a building control application to a local authority, there are two procedural routes:

• Full Plans application. Submit detailed drawings and specifications to the Building Control body before work starts. The drawings are checked against the Building Regulations and either approved or returned with comments. Once approved, the work is inspected at key stages and a Completion Certificate is issued on satisfactory completion. Statutory timescale: 5 weeks (or 2 months with written agreement).
• Building Notice. A shorter, simpler route for smaller works. You give the Building Control body at least 48 hours' notice of work starting, the work is inspected as it progresses, and a Completion Certificate is issued on satisfactory completion.

An alternative route is to use a registered Approved Inspector, who can take over the building control function via the Initial Notice mechanism under section 47 of the Building Act 1984. Approved Inspectors are listed on the Construction Industry Council Approved Inspectors Register (CICAIR).

For a comprehensive walkthrough of the application process, see our Building Control Application guide. For the simpler Building Notice route specifically, see our Building Notice guide. For the Approved Inspector transfer mechanism, see our Building Control Initial Notice guide.

Competent Person Schemes

For many routine categories of work, you can use a Competent Person registered with a government-approved scheme. The Competent Person self-certifies that the work complies with the Building Regulations, and the certification is recorded centrally. You do not need to make a separate building control application to the local authority in these cases.

Common Competent Person Schemes in England and Wales include:

• Gas Safe Register — for gas work.
• OFTEC — for oil-fired heating.
• HETAS — for solid-fuel heating.
• NICEIC, NAPIT, ELECSA — for electrical work.
• WaterSafe — for water regulations work.
• FENSA, CERTASS — for replacement windows and doors.

For a worked example of the Competent Person Scheme route in action (boiler installation), see our Boiler Installation Certificate guide.

Completion, compliance and sign-off

On satisfactory completion of the work, the Building Control body (local authority or Approved Inspector) issues a Completion Certificate. The Completion Certificate is a critical document — it is the formal proof that the work complied with the Building Regulations at the time of construction.

You should retain the Completion Certificate for the lifetime of the building, and it will be required when you sell the property. Without a Completion Certificate, a buyer's solicitor may:

• Insist on a discounted purchase price to cover the cost of retrospective certification.
• Insist on the work being inspected before exchange of contracts.
• In rare cases, withdraw from the transaction.

If a Completion Certificate was never issued and the work is recent, you may be able to apply for a regularisation certificate from the local authority. The fee is typically around 150% of the standard fee for the equivalent new-build work.

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