Building regulation drawings for extensions: what is needed?

Does an extension have to comply with building regulations?

Yes. Even where an extension is permitted development and needs no planning permission, you are still legally obliged to show it meets the Building Regulations. Building without approval can lead to enforcement action, problems with your mortgage or buildings insurance, and difficulty selling the property later.

What a building control submission includes

A building control application is usually made up of detailed building regulation drawings plus a structural design package. Between them they need to demonstrate compliance across every part of the build:

• Foundations: sized for the ground conditions and ground loads, allowing for nearby trees, drains and neighbouring structures.
• Ground floors: structurally stable, with damp-proofing and insulation to meet thermal standards.
• External walls: stability, weather resistance and thermal performance.
• Structural openings: beams and lintels where walls are removed or opened up for an open-plan layout.
• Upper floors: joist sizes, lateral restraint and fixing details.
• Roofs: rafters or beams, coverings, ventilation and insulation.
• The detail: windows and doors, flues, internal walls, drainage and ventilation.

Drawings and structural design under one roof

Because our architects and structural engineers work in the same team, the calculations and the drawings are coordinated from the outset. There is no gap between the two. We can typically prepare your building regulation drawings and structural design within 2–3 weeks, and submit the application to building control on your behalf.