Building regulations for extensions
Extension guide covering structure, insulation, drainage, fire safety, ventilation and completion evidence.
Project guides for extensions, lofts, garage conversions, outbuildings, structural work, services, drainage and certificate evidence.
Start with the page closest to your project, then use the linked tool or printable checklist to turn the guidance into questions for your building control body, designer, builder or registered installer.
Every published page keeps planning permission separate from building regulations approval and links back to official sources so you can re-check the current version before relying on it.
For a cleaner project file, save the likely route, record who is responsible for each certificate, and keep dated evidence before important work is covered up. If the work includes structure, fire safety, drainage, ventilation, electrics, heating or missing historic paperwork, confirm the route before committing money.
The strongest pages in this section are designed to answer one job at a time: choose a route, prepare an inspection, collect documents, or understand where planning permission sits outside building regulations. Use the cards as a sequence rather than a library. A sensible workflow is to read the most relevant guide, run the matching checker, print or save the evidence sheet, and then keep the official source panel with your project notes.
If a page points to UKPlanningGuide, treat that as a planning handoff only. Come back here for building-control approval, competent person certificates, Approved Document prompts, completion evidence and inspection records. That separation makes the project file easier to explain to builders, designers, surveyors, conveyancers and building control.
Comparison pages are especially useful before work starts because they expose trade-offs that are easy to miss in quotes: certainty versus speed, self-certification versus direct building-control involvement, and approval routes versus evidence routes. If a comparison still leaves you unsure, treat that uncertainty as a signal to ask building control earlier, not as a reason to choose the quickest route by default.
Use the section as a workflow: read the closest page, run the matching checker, print or save the evidence sheet, then keep the official source panel with your project notes.
The section avoids near-duplicate answers. Each card has a distinct job: quote preparation, inspection planning, certificate chasing, route comparison, sale evidence or a clear planning handoff.
When two pages seem close, open the one that matches the next real action in your project file. A homeowner who is choosing a route needs different evidence from someone chasing a missing certificate, preparing for a builder quote or trying to answer a buyer's conveyancing question.
Extension guide covering structure, insulation, drainage, fire safety, ventilation and completion evidence.
Fire escape, stairs, structure, insulation and ventilation requirements to discuss with building control.
Conversion checks for structure, damp, insulation, ventilation, fire safety and sound.
When garden buildings, offices and workshops move from exempt/simple to building-control relevant.
Garden office and habitable-use risk checks including electrics, drainage, sleeping use and size.
England-first homeowner guide to structural alteration building regulations, covering likely building-control routes, drawings, inspections, certificates, evidence and planning handoffs.
Beam, padstone, calculations, inspection and completion evidence guide.
Glazing, safety, thermal performance, ventilation and certificate evidence.
England-first homeowner guide to electrical work building regulations, covering likely building-control routes, drawings, inspections, certificates, evidence and planning handoffs.
Heating work, combustion appliances, competent person route and certificate evidence.
Drainage runs, new bathrooms, kitchens, extensions and soakaway/connection questions.