Planning Drawings vs Building Regulations Drawings

The short answer

Planning drawings and building regulations drawings are two different things, prepared for two different purposes. Planning drawings are about whether you are allowed to make a change; building regulations drawings are about how that change is safely and properly built. Most projects that need planning permission will also need building regulations drawings before construction can start, so the two stages usually happen in sequence rather than instead of one another.

What planning drawings show

Planning drawings communicate the proposed design to the local planning authority so it can decide whether the change is acceptable in principle. They typically include existing and proposed plans, elevations and sections, a site plan and a location plan, sometimes supported by a design and access statement or heritage statement.

They focus on the things planning cares about: the appearance and scale of the proposal, its effect on neighbours and the street scene, and its compliance with local policy. They do not usually contain the technical construction detail needed to actually build the project.

What building regulations drawings show

Building regulations drawings provide the technical information that satisfies building control and allows a builder to construct the work compliantly. They cover structure, fire safety, insulation and energy efficiency, ventilation, drainage, stairs and guarding, and — for basements — waterproofing.

These drawings are typically more detailed than planning drawings and are usually accompanied by structural engineer’s calculations and specification notes. They are what turns an approved design into a buildable, compliant project.

Why builders need technical drawings

If a builder prices from planning drawings alone, they are pricing with incomplete information and filling the gaps with assumptions — usually priced as risk, which makes quotes higher and harder to compare. A coordinated set of building regulations and tender drawings lets contractors price the same scope on a consistent basis and build from clear information, reducing variations and disputes on site.

When structural calculations are needed

Whenever a project involves new or altered structure — removing a wall, forming an opening, adding a beam, building an extension or excavating a basement — a structural engineer is usually required to design and calculate that structure. The calculations sit alongside the building regulations drawings, and building control will expect to see them. We coordinate the structural engineer so the drawings and calculations are consistent.

Permitted development and when planning may not be needed

Some house projects may fall under permitted development, meaning planning permission is not required — but building regulations approval is still usually needed. Even where you do not need planning drawings, you will generally still need building regulations drawings to build safely and lawfully. Permitted development cannot be assumed, particularly in conservation areas, for flats and maisonettes, and for listed buildings.

Why flats and listed buildings are different

Flats and maisonettes generally do not benefit from permitted development rights for extensions, and alterations usually require freeholder consent through a Licence to Alter as well as building regulations approval. Listed buildings require listed building consent for many internal and external alterations, separate from planning permission. In both cases the route is more involved, and assuming a simple path can be a costly mistake.

What to send us for advice

If you are unsure which drawings you need, send us the property address, the type of property (house or flat), and a short description of what you want to do. We will advise the likely route — planning, building regulations, or both — and what information will be required before you commit to a full design package.