Building Regulations

It helps to think of them as two separate gatekeepers looking at different things. Planning is concerned with whether you should be allowed to build something in this location, at this size, in this form. Building Regulations are concerned with whether the thing that gets built is structurally sound, safe, healthy to live in and reasonably efficient — regardless of whether planning permission was needed to build it.

This is why routine work that falls entirely within permitted development for planning purposes, such as many single-storey extensions, still needs Building Regulations approval in full.

The Approved Documents set out guidance against the current Building Regulations for England, organised broadly by topic. Requirements are updated periodically, so always check the current version rather than relying on what applied to a previous project.

Building control functions can be carried out by the local authority Building Control service, or by a registered building control approver working under the current registration regime for building control professionals. Whichever route is chosen, they must be formally engaged before work starts — retrospective sign-off is not straightforward and can require opening up completed work.

At the end of the job, satisfactory completion is confirmed through a completion certificate (local authority route) or a final certificate (registered approver route). This paperwork matters for future sales, mortgages and insurance, so it should be filed and kept, not just accepted verbally on site.

Inspections generally need to be booked with notice, and work should not proceed past a hold point until it has been signed off — pouring over an uninspected foundation or backfilling an untested drain run risks having to expose it again, at cost and delay. Building the inspection sequence into the programme from the outset, including who is responsible for booking each visit, avoids the most common site delays on regulated stages.

Where the local authority route is used, there are generally two ways to apply: a full plans application, where drawings and calculations are checked and approved before work starts, and a building notice, where work can start with less upfront checking but carries more risk if something is later found not to comply. Full plans is usually the better route for anything beyond simple domestic work, because problems are caught on paper rather than on site.

A registered building control approver works differently again, engaging directly with the design team and carrying out inspections under their own registration rather than the local authority's. Whichever route is chosen, it needs to be settled and the body formally notified before excavation starts, not part-way through.

Below-ground and early-stage work carries a disproportionate share of Building Regulations risk because so much of it is covered up quickly. Foundation type and depth need to suit the ground actually found on site, not just the ground assumed at design stage — a hold point exists at excavation partly so the inspector can confirm the ground matches the design.

Thermal performance requirements affect groundworks more than people expect: insulation position and thickness under a slab, edge insulation to avoid cold bridging at the perimeter, and the position of the damp proof membrane relative to the insulation all have to be right first time, because none of it is visible once the floor is finished.

Work carried out without the required Building Regulations approval does not become compliant simply by being finished — a regularisation application can sometimes be made after the fact, but it usually costs more than doing it properly at the time, because completed work often has to be exposed again for inspection. This is a particular risk when buying a property with undocumented past extensions or conversions, where a lack of a completion certificate is worth investigating before purchase, not after.

Planning conditions and Building Regulations requirements sometimes overlap — a condition might, for example, require a specific level of thermal performance or a particular drainage strategy that also needs to satisfy Building Regulations. The two processes are checked by different bodies and do not automatically share information, so confirming that a design satisfies both, rather than assuming one covers the other, avoids a project meeting one requirement and failing the other.

SHS is the contractor, not the planning authority. What SHS can do is look at the regulated stages of your build from a build point of view — access, ground conditions, levels, drainage, foundations and buildability — and tell you plainly what the construction side is likely to involve.

If drawings already exist, send them. If they do not, a site visit and a conversation usually establishes what information you need to gather next and who you need it from.