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Building

Expert advice on structural work, home extensions, renovations and understanding building regulations.

Building

Home Improvements - What Are Building Regulations?

Building Regulations are designed to keep people safe and to make sure that domestic and commercial properties are structurally sound as well as energy and water efficient.

Building Regulations are designed to keep people safe and to make sure that domestic and commercial properties are structurally sound as well as energy and water efficient.

Building Regulations are often confused with Planning Permission, but they are two separate things. Planning Permission is the initial permission to build or develop a building. Building regulations control the safety and construction of a building works. They are set standards which apply to all building works undertaken in England and Wales; Scotland has its own Building Regulations. Building Regulations also cover the provision of facilities for people with disabilities and appropriate access in and around buildings.

If you use a professional builder, architect or installer, they will be able to advise you on what you need to do and make sure that your works are signed off.

What Are Building Works?

Building works include all of the following – if you are undertaking this work on your property, you need to make sure it meets Building Regulations and gains the relevant approval:

  • Any alterations or renovations which will affect existing Building Regulations compliance, including fire safety, access and structure.
  • Extensions, conversions or erection of a building.
  • Cavity wall installation.
  • Underpinning the foundations of a building.

The following are considered to be building works and need Building Regulation approval, but can be approved by a trader who is registered with the relevant Competent Persons Scheme:

  • Installation of windows (using a company that is registered with FENSA).
  • Replacement or alterations to electrical circuits near baths or showers.
  • Installation of new or replacement boiler.
  • Installation of fuel burning appliances.
  • Installation of new, or alteration of existing, plumbing.
  • Roof cover replacement.

Building Regulation Categories

There are fifteen different categories of Building Regulations. Known as “approved documents”, different home improvement projects will fall into different categories. The categories, labelled A to Q, are:

  • Part A: Structural safety
  • Part B: Fire safety
  • Part C: Site preparation, resistance to contaminants and moisture
  • Part D: Toxic substances
  • Part E: Resistance to sound
  • Part F: Ventilation
  • Part G: Sanitation, hot water and water efficiency
  • Part H: Drainage and waste disposal
  • Part J: Heating and appliances
  • Part K: Protection from falling, collision and impact
  • Part L: Conservation of fuel and power
  • Part M: Access to and use of buildings
  • Part N: Glazing safety
  • Part P: Electrical safety
  • Part Q: Security

If you don’t get Building Regulations approval, your property could be at risk, and it could prove hard to sell further down the road. Your tradesperson should be able to guide you through the Building Regulations process – to save making changes to your home that are not compliant with Building Regulations, choose a reliable builder, gas engineer or double-glazing specialist who is registered with a Competent Persons Scheme.

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Looking for more building advice?

Find clear, practical answers to common building questions, helping homeowners understand everyday issues, know what checks they can carry out safely, and when it is best to contact a qualified professional.

  • Do I need planning permission for a home extension?

    Plenty of extensions don't need planning permission - they fall under Permitted Development. Whether yours qualifies depends on the size, location, and type of build. Single-storey rear extensions up to four metres on a detached house often get the green light, but side extensions, two-storey builds, and properties in conservation areas usually do need permission. Always check with your local planning authority before you start - building without the right approvals can mean being made to undo it all.

  • What is involved in building a conservatory?

    You're looking at groundworks and foundations, the frame and glazing, the roof, and then the internal fit-out - flooring, heating, electrics. Most conservatories under a certain size fall under Permitted Development, but they still need to comply with Building Regulations, especially if you want to use the space as a proper room year-round. On the roof: solid or tiled options make a huge difference to usability - traditional polycarbonate can be unbearably hot in summer and freezing in winter. Most projects take two to six weeks.

  • Do I need a structural engineer for my home renovation?

    Not for everything - but if structural changes are involved, yes. Removing a load-bearing wall, putting in a steel beam, touching the roof structure, or adding a sizeable extension all need a structural engineer to design the solution and produce the calculations for Building Regulations approval. A builder might tell you whether a wall is load-bearing, but only a structural engineer can specify the right beam and carry professional liability for that advice.

  • Do I need planning permission to install patio doors?

    Usually not, if you're replacing an existing door or window in the same opening - that typically falls under Permitted Development. But if you're making the opening larger or creating a new one in an external wall, you may need planning permission or Building Regulations approval. Conservation areas, listed buildings, and properties with an Article 4 Direction have tighter rules, so check before assuming. Any structural work to the opening, like fitting a new lintel, needs Building Regs sign-off regardless.

  • Does my extension need Building Regulations approval even without planning permission?

    Almost always, yes. Planning permission and Building Regulations are two separate things. Extensions need to meet regulations covering structural integrity, fire safety, insulation, ventilation, and drainage - regardless of whether you needed planning approval. Your local authority's building control team can confirm exactly what's required. And don't skip it - missing Building Regs sign-off can cause real headaches when you come to sell.

  • How long does a typical home extension take?

    A small single-storey extension usually takes eight to twelve weeks from groundworks to completion. Add several months if planning permission is needed before work can even begin. Bigger builds - two-storey additions or anything needing significant structural work - can take four to six months or more. Get a realistic timeline from your builder upfront, and factor in a buffer for the unexpected.

Have a question about TrustATrader?

If you have a question in relation to TrustATrader specifically, please check out the TrustATrader FAQs, with separate lists tailored to consumers and tradespeople. Alternatively, get in touch with our team. We're happy to help!