People often hear they need 'drawings' and assume it's one thing. In fact most home projects involve two distinct sets, prepared at different stages for different purposes: planning drawings and building-regulations drawings. Knowing the difference helps you understand what you're paying for and when.
In short
Planning drawings are about what you want to build and how it looks; building-regulations drawings are about how it's constructed and meets safety and energy standards. Most extensions and loft conversions need both, at different stages.
Not sure which route applies to your property? Send Sean your postcode, a few photos and a short description for an honest first view — with no obligation.
Reviewed by Sean Corser, SC Design & Construction. Sean Corser helps Wirral homeowners with architectural design and drawing packs for extensions, loft conversions, planning and building regulations.
Last reviewed June 2026
Planning drawings support a planning application. They show what you want to build and its impact: existing and proposed floor plans, elevations (how it looks from each side), and a location/site plan identifying the property.
Their job is to let the council assess the proposal's size, appearance and effect on neighbours and the area. They are not detailed enough to build from.
Building-regulations drawings come later and are far more technical. They show how the work is constructed and how it meets the regulations: construction sections, junction details, insulation, fire safety, drainage, ventilation and structure.
These are what building control checks and what a builder needs to construct the project correctly.
Often, yes. A project might need planning permission (so planning drawings) and will almost always need building-regulations approval (so building-regs drawings) — even if it's permitted development and skips the planning stage.
Some small internal projects need neither; some need only building regs. We advise on which applies to your specific project.
Typically you settle the design, obtain planning permission (or confirm permitted development), then prepare building-regulations drawings for the build. Doing them in the right order avoids paying to detail a scheme that later has to change for planning.
A few details are enough for an honest first view — with no obligation:
External links open in a new tab. Always confirm your specific project with the relevant authority.
Send Sean a few photos and a short description of what you'd like to do. You'll get an honest first view with no obligation.