Planning Drawings vs Building Regulations Drawings

What Is the Difference?

Planning drawings explain the proposed changes to your home: the layout, size, position and appearance. Building Regulations drawings develop the technical details needed to show how the work will meet the relevant construction standards.

For many extensions and loft conversions, you will need both stages. They serve different purposes, even when they start from the same agreed design.

What Do Planning Drawings Show?

Planning drawings help the council assess how your proposal relates to the existing house, neighbouring properties and the surrounding area.

A typical householder drawing package may include:

• Existing and proposed floor plans showing the room layout.
• Existing and proposed elevations showing the outside appearance.
• A location plan and a site or block plan.
• Roof plans and sections where needed to explain the proposal.
• Key dimensions and proposed external materials.

The information required depends on the project and the council's application requirements. These drawings establish what you intend to build, but usually do not contain all the construction information a builder needs.

What Do Building Regulations Drawings Show?

Building Regulations drawings take the agreed layout further by adding technical notes, sections and construction details. They help building control assess the design and give the builder information about the intended construction.

Depending on the work, they may cover:

• Foundations, floors, walls and roof construction.
• Insulation, damp protection and ventilation.
• Fire safety, escape arrangements and stair design.
• Drainage and other relevant services.
• Structural supports, with supporting calculations where required.

The level of detail varies with the project. Specialist information, such as structural calculations, may accompany the drawings rather than appear entirely on the drawing sheets.

Does Permitted Development Mean I Only Need One Set?

A project that meets the permitted development rules may not need a planning application. That does not remove the need to consider Building Regulations.

For example, a loft conversion may fall within permitted development limits while still requiring technical design information for its new floor, stairs, insulation and fire safety arrangements.

Drawings can also help demonstrate the proposal when applying for a lawful development certificate. The correct route should be checked for your property before work starts.

Which Drawings Should Be Prepared First?

We usually begin with a measured survey and develop the layout with you. Where planning permission is needed, it is often sensible to resolve that stage before completing the detailed Building Regulations package.

This helps avoid spending time on construction details for a design that may change during the planning process. The stages can sometimes overlap, depending on the project and your timescale.

Can a Builder Quote from Planning Drawings?

A builder may be able to give an initial estimate from planning drawings. For a more informed quotation, detailed drawings and a clear description of the work help explain what should be included.

Agree the scope, finishes, fittings and any exclusions with the builder as well. Building Regulations drawings do not automatically specify every item in your building contract.

Are Approved Drawings the End of the Process?

No. Building control also inspects work during construction. Approval of the plans is a different stage from the completion certificate issued once building control is satisfied with the completed work.

If the layout or construction changes, check whether updated drawings or further approval are needed before carrying out the change.