Planning permission and building regulations are two different things, and it's easy to confuse them. Planning is about whether you can build; building regulations are about how it's built — structure, safety, insulation, fire and more. Most extensions and habitable loft conversions need building-regulations approval even when planning permission isn't required.
In short
Planning is about whether you can build; building regulations are about how it's built. Most extensions and habitable loft conversions need building-regs approval even when planning permission isn't required — and the two are entirely separate processes.
Not sure which route applies to your property? Send Sean your name and one way to contact you for an honest first view — with no obligation. A postcode, a few photos and a short description help if you have them, but aren't required to start.
Reviewed by Sean Corser, SC Design Wirral. Sean Corser helps Wirral homeowners with architectural design and drawing packs for extensions, loft conversions, planning and building regulations.
Last reviewed June 2026
Building regulations set minimum standards for the work itself: structural stability, fire safety, insulation and energy efficiency, ventilation, drainage, stairs and access, and more.
They apply to most building work — extensions, loft conversions, structural alterations and many internal changes — regardless of whether planning permission is needed.
Building-control approval is usually supported by technical drawings and specifications showing how the work meets the regulations — construction details, sections, insulation and structural information.
We prepare clear architectural and building-regulations drawings for your project, so building control and your builder both have what they need.
There are two routes. A full plans application means your drawings are checked and approved before work starts — the safer option for extensions and loft conversions. A building notice involves less paperwork but more risk, as issues are only caught during inspection.
We generally recommend the full plans route for anything structural, so problems are designed out rather than discovered on site.
Approval is obtained either through your local authority building control or an approved inspector, and the work is inspected at key stages.
We help you understand the process and what each stage involves, so it feels far less daunting. Keep the completion certificate safe — a buyer's solicitor will ask for it.
You don't need a full brief or drawings to get started — just your name and one way to contact you. The rest is optional, and you can send more whenever it suits you.
External links open in a new tab. Always confirm your specific project with the relevant authority.
All you need to start is your name and one way to contact you. A short description, postcode or a few photos help if you have them — but they're not required.