Planning permission versus building regulations, explained plainly

01

Planning permission, the what and the where

Planning is the local authority deciding whether the development is acceptable in principle and in appearance. Cornwall Council weighs it against the local plan, neighbourhood plans, and any designation covering the site. The drawings are about scale, siting, massing, materials and the effect on neighbours and the street, not about how the wall is built.

• Decided by the local planning authority, with a published decision notice
• Statutory determination period is usually eight weeks for a householder application
• Neighbours and consultees can comment, and comments are public
• Conditions are often attached and must be discharged before or during the build

02

Building regulations, the how

Building regulations are national standards for construction. Approval comes from Building Control, either the council's service or an approved inspector, and it is judged against the Approved Documents covering structure, fire safety, ventilation, insulation, drainage, accessibility and more. Nobody is assessing whether the extension suits the street. They are assessing whether the lintel is big enough and the insulation continuous.

• Applies to most structural work whether or not planning permission is needed
• Two routes, a full plans submission checked in advance, or a building notice inspected as you go
• Site inspections happen at stages, and a completion certificate is issued at the end
• The completion certificate is the paperwork a buyer's solicitor will ask for

03

How the two run together on a real project

In practice the planning drawings come first, because there is no point detailing a scheme that has to change shape. Once permission is granted, the same design is developed into a technical package for building regulations and for the builder. Where a project is permitted development, planning is skipped and the technical package still happens. Where a project is internal only, such as a structural opening, building regulations apply and planning usually does not.

04

Where people get caught out

The most common problem we see is work built without building regulations approval because planning was not needed, so the owner assumed no approvals applied at all. The second is a planning condition, on materials or drainage for example, that is never formally discharged, which leaves the permission technically unimplemented. Both surface at sale, years later, and both are avoidable at the start.