Two sets of rules govern most building work on an English home, and people routinely confuse them. Planning permission asks whether a development is acceptable in its location. Building regulations ask whether the work itself is safe, healthy and energy efficient. A project can need one, both or neither. A loft room under permitted development may need no planning application and still need full building regulations approval; a new bathroom may need no planning permission and still touch regulations on drainage, ventilation and electrics. This guide sets out how the system works in England, which common projects are normally covered, what is usually exempt, and what the consequences are if you skip it.

What building regulations are

In England the main legislation is the Building Regulations 2010, which cover the construction and extension of buildings. The detail is in the Approved Documents, which are published by the government and give practical guidance on how to comply. Each document covers a topic, identified by a letter, and the collection on GOV.UK lists them all. The main ones for home projects are:

  • Part A Structure, including loading, foundations and floor and roof sizes.
  • Part B Fire safety, including escape routes and fire resistance.
  • Part C Site preparation and resistance to contaminants and moisture.
  • Part E Resistance to the passage of sound.
  • Part F Ventilation.
  • Part G Sanitation, hot water safety and water efficiency.
  • Part H Drainage and waste disposal.
  • Part J Combustion appliances and fuel storage.
  • Part K Protection from falling, collision and impact, which includes stairs and guarding.
  • Part L Conservation of fuel and power.
  • Part M Access to and use of buildings.
  • Part P Electrical safety in dwellings.

There are further parts for overheating and for infrastructure such as electric vehicle charge points. The approved documents are guidance rather than law; you can comply another way if you can demonstrate it, but following them is the usual route. They apply in England. Wales has its own regulations, with its own approved documents, and Scotland and Northern Ireland have separate systems, covered below.

Planning permission is a different question

The Planning Portal states that building regulations approval is different from planning permission, and you might need both. Many projects that are permitted development still need building regulations approval, even if your project is covered by permitted development rights. If you are unsure whether your extension or loft room needs planning, see our guides on permitted development for rear extensions and loft conversions under permitted development. The permitted development extension compliance audit helps with the planning side. Neither of these answers the building regulations question, which is separate.

Projects that normally need approval

The Planning Portal's common project guides cover dozens of types of work. The following are the ones that nearly always involve building control in England, though the details of each case matter, so always check with your local building control team.

  • Extensions. The Planning Portal says that most extensions of a property require approval under the building regulations. A few small, simple extensions fall into exempt classes.
  • Loft conversions. Structure, fire escape, stairs, insulation and electrics are all affected. See our loft conversion guide.
  • Removing or altering load-bearing walls and chimney breasts. Needs a structural design, and often steel beams.
  • Garage conversions. Turning a garage into a habitable room triggers requirements for insulation, damp, ventilation, escape and more.
  • New drains and altering existing drainage, including connecting to a sewer or building near one.
  • Changes to heating systems, such as installing a new boiler or heat pump, which fall under Parts J, L and G.
  • Replacing windows and doors, unless the work is done by an installer who is a member of a competent person scheme.
  • Some electrical work. Installing a new circuit, replacing a consumer unit and certain other works are notifiable. See our guide to Part P electrical work.
  • New buildings, including outbuildings that exceed the exemption limits, discussed below.
  • Underpinning, basements and substantial structural change.
  • Charge points and other new services, where the electrical rules apply. See our guide to home EV charger installation.

The Planning Portal also lists bathroom and kitchen installations as relevant where the work involves plumbing, drainage, ventilation or electrics, even though the planning side is generally not an issue.

Projects that are often exempt, and the conditions

Schedule 2 of the Building Regulations lists classes of work that are exempt. Exemption always depends on conditions, so treat the following as a prompt for checking, not a final answer.

  • Small detached outbuildings. The Planning Portal states that building regulations will not normally apply to a detached outbuilding with a floor area under 15 square metres that contains no sleeping accommodation. Between 15 and 30 square metres, approval is usually not needed if there is no sleeping accommodation and the building is either at least 1 metre from any boundary or built substantially of non-combustible materials. A garden room used as a bedroom, or one over 30 square metres, is a different matter. See our guide to building a shed base for the planning rules on outbuildings.
  • Detached garages and attached carports. The same floor-area tests apply to detached garages. An attached carport that is open on at least two sides is generally exempt if it is under 30 square metres.
  • Fences, gates and garden walls. No building regulations approval is usually needed for a normal boundary wall or fence, though the planning limits on height still apply. See our garden brick wall guide.
  • Patios and paths at ground level. Generally no approval, but see the notes on drainage and damp-proof courses in our patio guide.
  • Decorating and minor repairs. Painting, wallpapering, plastering repairs and like-for-like replacement of fixtures are normally outside the regulations, although there are exceptions where replacement affects structure, fire safety or energy efficiency.
  • Some porches and conservatories. Small ground-level porches and conservatories can be exempt if they meet conditions, including being separated from the house by external-quality walls and doors and having their own heating arrangements. Do not assume; check.

Whether or not a project needs formal approval, the work must still comply with the regulations' technical requirements. The Planning Portal puts it this way for outbuildings: if the regulations do apply, the building must be built to reasonable standards. Exemption from approval does not mean exemption from the standards.

Who can approve the work

In England you can choose between your local authority building control department and a private registered building control approver. Both inspect your work and, when satisfied, issue the documentation. Higher-risk buildings are in a separate regime, controlled by the Building Safety Regulator, which does not normally affect a house or small block. Your choice does not change the standards applied, but the fee, the service and the approach to inspections differ, so compare quotes.

Full plans or building notice

Local authorities typically offer two ways to apply. A full plans application submits detailed drawings and specifications before work begins, and building control checks and approves them. A building notice lets you start work after giving notice, usually 48 hours, without submitting detailed plans, and building control inspects as the work proceeds. A building notice is quicker to start but riskier for complex work, because errors only appear on site. Check the options and fees with your building control team, since procedures vary between authorities.

Competent person schemes

GOV.UK explains that if the work is done by someone registered with a competent person scheme, you do not need to get approval yourself. Common schemes cover electrical installation, gas and heating installation, window and door replacement and some other trades. The installer certifies the work and notifies the building control body, and you receive a certificate. Check the installer's registration on the scheme's own website; the umbrella site for such schemes is listed at competentperson.co.uk. Keep the certificates, because buyers' solicitors will ask for them.

What if you do the work without approval?

GOV.UK states the person doing the work could be prosecuted and fined if the work does not comply with building regulations, and the building control body could make you pay to fix faulty work. Without approval you will not have the certificates of compliance that you may need when selling your home, and unapproved work can hold up a sale, affect insurance claims or force costly opening-up for inspection. Safety is the real point: structural, fire and electrical defects are hidden once the plaster is on.

If you discover that work was done without approval, perhaps before you bought the house, local authorities in England can often issue a regularisation certificate for unauthorised work, after inspection and sometimes opening-up of the works. Ask your building control team how this works locally. An indemnity policy is sometimes offered in sales, but it does not make the work compliant.

Other consents that may apply

  • Party Wall etc. Act 1996. Work on or near a shared wall or boundary, or excavation close to neighbouring buildings, can require notice to neighbours. See the GOV.UK guidance.
  • Listed buildings and conservation areas. Listed building consent and extra planning rules can apply.
  • Utilities and sewers. Building over or near public sewers can need the water company's agreement.
  • Leasehold and covenants. Freeholder consent or restrictive covenants may apply, irrespective of the law.

Scotland, Wales and Northern Ireland

These rules are England-specific. GOV.UK notes that Scotland and Northern Ireland have their own rules. In Scotland, building standards are administered by local authority verifiers and many works need a building warrant; see the Scottish Government's building standards pages. In Northern Ireland, building regulations are made by the Department of Finance, and applications go through the council's building control. Wales has its own building regulations and approved documents. Thresholds, exemptions and terminology differ, so do not apply the English figures quoted here elsewhere.

A simple decision process

  1. Write down exactly what you plan to do, including any plumbing, wiring, structure or heating that changes.
  2. Check the Planning Portal's common project page for that project, then the relevant Approved Document.
  3. Ask building control by phone or email if you are uncertain. Many offices answer simple questions for free.
  4. If you are hiring, ask whether the tradesperson is registered with a competent person scheme for the work and get the certificate.
  5. Keep all drawings, certificates and completion documents with your house records.

This is general information on rules that change, not legal or professional advice. Confirm with your local building control team or a qualified professional before starting.

Sources