Building control is the system that checks a building is safe, warm, ventilated and drained. It runs entirely independently of planning: an extension can have planning permission and still be unlawful to build, or need no permission at all and still need full building control approval. This page covers what the drawings must show and which approval route to take.
MCIAT chartered drawings for planning, building regs, lofts and extensions — fixed fees 30% below typical London architects. Tell us what you need and we’ll reply the same working day.
A Full Plans application submits the drawings and calculations for assessment before work starts. The body has five weeks to decide, extendable to eight by written agreement, and the outcome is a plans approval notice — a document a buyer's solicitor will ask to see years later.
A Building Notice skips that check. Work can start 48 hours after notifying, and compliance is judged purely on site. It suits like-for-like work with no structural content. On anything involving a beam, a new floor, a loft or a change of use, we submit Full Plans, because the alternative is discovering a disagreement about a detail after it has been built and covered up.
Both routes are lawful and both produce a completion certificate. A local authority building control department and a private approved inspector apply the same Building Regulations; what differs is availability, responsiveness and fee. Private inspectors often book site visits faster, which matters when a builder is waiting on a foundation inspection.
Registration requirements for building control professionals changed under the Building Safety Act 2022 regime, so it is worth confirming your inspector's current registration before instructing — for domestic work either route remains straightforward. We produce the same drawing set for either, and we will submit to whichever body you choose.
Fees vary by authority and by project value rather than following a national scale, which is why we quote them per job rather than publishing a figure that would be wrong in most boroughs.
The set states performance targets explicitly, because the inspector checks against stated values rather than inferring them. Part L: about 0.18 W/m²K for a new wall, 0.16 for a roof, 1.4 for a window, 2.2 for a rooflight. Part F: 30 l/s extract over a hob, 15 l/s in a bathroom, 6 l/s continuous in a utility. Part K: 42° maximum stair pitch, 220mm going, 2m headroom.
Part B drives the fire strategy. Above 4.5m from ground level to floor, a protected escape route is required with FD30 doors to the habitable rooms opening onto it, and an escape window of at least 0.33m² clear openable area. Part A brings the structure: beam and lintel sizes derived from real loads, with deflection limited to span/360, foundation depths and, where relevant, the effect on the party wall.
Typically: excavation before concrete, foundation concrete, damp-proof course and oversite, drainage before covering and again on test, structural steelwork and its connections, insulation before it is closed up, and completion. Miss one and the inspector can require opening up finished work, which is the single most expensive avoidable event on a domestic build.
The drawings matter here more than at submission. A set that shows each junction properly gives the builder something to build to and the inspector something specific to check, which is why disputes at the insulation stage are usually really disputes about an ambiguous detail drawn months earlier.
Our combined package — planning drawings, building regulations drawings and structural calculations — is £1,750 fixed. Structural calculations alone are £350. The building control body's own fee is separate, varies by authority and by project value, and we quote it per job rather than publishing a national figure that would be wrong in most boroughs.
Yes. Permitted development is a planning concept and says nothing about structural safety, fire, insulation, ventilation or drainage. Almost all extension and conversion work requires building control approval regardless of whether planning permission was needed, and the two applications run independently of each other.
A regularisation application can be made retrospectively to the local authority, which will usually require opening up parts of the work to inspect what is hidden. It is more expensive and less certain than approval in advance, and the absence of a completion certificate is a standard query on a conveyancing search when you sell.
A Full Plans application has a statutory decision period of five weeks, extendable to eight by written agreement. A Building Notice allows work to start 48 hours after notification with no plan check at all — faster to begin, but with the risk of a compliance disagreement discovered on site.
No. A planning drawing carries no U-values, no beam sizes and no fire strategy, because a planning officer has no remit over any of them. A building control drawing carries all three and says little about street appearance. Both are needed on most projects, which is why we price them as a combined package.
Tell us what you are building. Fixed fee and a Full Plans submission target back the same working day.
Get a fixed-fee quoteBefore you commit, it is worth understanding transparent fixed fees and seeing our 98% approval record. You can search by service or borough to find the right fit, or set up your account to track your project. When you are ready, get a quote for your project — most homeowners have a fee in minutes — or contact us and a chartered technologist will be in touch.