Building regulation drawings across Cornwall.

Cornwall specifics

Building regs drawings tuned to the way Cornwall actually builds.

FAQs

Building regulation drawings in Cornwall — questions we get every week.

What are building regulation drawings?

Building regulation drawings (often called 'building regs drawings' or 'Full Plans drawings') are the technical construction package a builder works from and a Building Control surveyor signs off against. They include scaled plans, sections and elevations, plus detailed information on structure, foundations, insulation (Part L), ventilation (Part F), fire safety (Part B), drainage (Part H) and energy performance. They are different from planning drawings, which are about what a building looks like — building regs drawings are about how it's actually built.

Do I always need building regulation drawings in Cornwall?

For almost every extension, loft conversion, structural alteration, new build, garage conversion and material change of use, yes. Cornwall Council's Building Control service (or any Approved Inspector you appoint) needs either a Building Notice or a Full Plans application before work starts. We recommend Full Plans drawings on anything beyond the smallest jobs — it gives you a fixed-price tender, fewer surprises on site, and written approval before the first trench is dug.

What's the difference between Full Plans and a Building Notice?

Full Plans means submitting a complete drawing package up-front; Building Control checks and approves it, then visits stages on site. Building Notice means you tell them you're starting and they inspect as you go — no drawings approved in advance. Full Plans is slower to start but far cheaper to fix problems on, because issues are caught on paper. We do almost everything as Full Plans for that reason.

What scales should building regulation drawings be drawn at?

Plans, elevations and sections at 1:50. Construction details — eaves, thresholds, junctions, parapets, lintels — at 1:10 or 1:5. Site plans at 1:200 or 1:500. Anything tighter than 1:10 starts to lose useful structural information; anything looser than 1:50 won't pass a Cornwall Building Control check on key dimensions. Our packs cover all three scales as standard.

How much do building regulation drawings cost in Cornwall?

For a typical single-storey rear extension or loft conversion in Cornwall, a full building regs package usually runs £1,200–£2,400 plus VAT, depending on complexity and how much structural coordination is needed. Larger or more complex projects (two-storey extensions, new builds, listed buildings, complex steel grids) cost more. Cornwall Council's own Building Control fees are separate, set on a sliding scale by project value.

How long do building regulation drawings take?

Allow two to four weeks for drawing production on a typical extension, plus another five weeks for Cornwall Council Full Plans approval. Structural engineer's calculations usually slot in alongside the drawing work, not after. We sequence the design so that planning, structure and building regs all hit at the right point and the build can start without dead weeks.

Do you coordinate the structural engineer?

Yes — every Full Plans package goes out with structural calculations coordinated against the architectural drawings, so the steel sizes on the engineer's package match the openings on the construction drawings. We work with a small group of Cornwall-based structural engineers and the round-trip is usually a week, not three.

Will the drawings get my project past Cornwall Council Building Control first time?

That's the goal of doing it as Full Plans. We design to current Approved Documents (Part A through Part S), specify products by reference, and show enough detail at 1:10 that the surveyor isn't being asked to take anything on trust. First-time approval isn't guaranteed by anyone — but our pass rate without conditions is high, and conditions when they come are usually small clarifications, not redesigns.

Can builders price the job properly from your drawings?

Yes — that's the test we hold the package to. A Cornwall builder should be able to take our pack, walk the site once, and come back with a fixed-price tender that isn't full of provisional sums. If the drawings need to be interpreted on site, they're not done. We'd rather spend an extra day on a junction detail than have you absorb a £4,000 variation in week six.

Do you do drawings if someone else did the planning?

Yes — we regularly pick up planning-approved schemes from other practices and produce the building regs package for the build. We'll need the planning drawings, decision notice and any approved conditions, plus a measured survey if the original was thin. Lead time is usually three to four weeks from instruction.