Building Regulations are one of the most misunderstood parts of any building project. Homeowners often assume that if they don't need planning permission they don't need anything else, or that their builder will "sort the paperwork" without really knowing what that involves. This guide answers the questions we hear most often about Building Regulations and Building Control in Cornwall, so you know what to expect before work starts. It's general guidance rather than legal advice, and the right route always depends on the details of your project.
What are Building Regulations?
Building Regulations are national minimum standards for how buildings are designed and constructed in England. They cover areas such as structure, fire safety, insulation and energy efficiency, ventilation, drainage, sound insulation, access and electrical safety. Each area is set out in a separate part of the regulations, with official guidance documents (the Approved Documents) showing common ways to comply.
The aim is that the finished building is safe, healthy, energy efficient and accessible. Unlike planning, Building Regulations aren't about whether something looks right or fits in with its surroundings.
How is this different from planning permission?
It helps to think of them as two separate questions:
Planning permission asks whether you can build it at all: its size, appearance, use and impact on neighbours and the area.
Building Regulations ask whether it's built properly: whether the structure, fire safety, insulation and so on meet the required standards.
Many projects need both. Some need only one. A single-storey rear extension built under permitted development may not need a planning application, but it will almost always need Building Regulations approval. Our guide to planning permission in Cornwall covers the planning side in more detail.
What work needs Building Regulations approval?
As a general guide, approval is usually needed for:
Home extensions, including most single and two-storey extensions
Loft conversions and garage conversions into living space
Structural alterations, such as removing or altering a load-bearing wall or chimney breast
New or altered drainage, and work close to or over a public sewer
Installing new heating appliances, wood burners and flues
Changing the use of a building, for example converting a barn into a home
Most electrical work in kitchens and bathrooms, and new circuits
Some work can be self-certified by an installer registered with a competent person scheme, such as replacement windows, boiler installation or electrical work, and they notify Building Control for you. Many small porches, conservatories and garden buildings are exempt if they meet certain conditions, and like-for-like repairs usually don't need approval. If you're unsure, ask before work starts.
Who provides Building Control in Cornwall?
You have a choice. You can use Cornwall Council's Building Control service, or a private registered building control approver (previously known as an approved inspector). Both check plans, inspect work on site and issue the final certificate. Building control professionals carrying out this work must now be registered with the Building Safety Regulator. The choice is often about service, availability and cost, and your architect, designer or builder may have a view on what works best for your project.
Full plans or building notice?
When you use Cornwall Council, there are two main ways to apply:
Full plans application. Detailed drawings and specifications are submitted and checked before work starts, and you receive an approval decision. It takes longer up front but gives everyone certainty, and it's the better route for extensions, loft conversions and anything structural.
Building notice. You give notice and work can start shortly afterwards, with compliance checked on site as the job progresses. It can suit smaller, simpler jobs, but there's no approved set of plans, so problems may only show up once work is underway. It isn't available for every type of work.
There is also a regularisation route for some work that was carried out without approval, though it can involve opening up finished work for inspection. A private approver uses its own process, called an initial notice, rather than these two routes.
What happens during inspections?
Building Control needs to be told before work starts and at key stages. Typical inspection points include:
Foundation excavations, before concrete is poured
Oversite or floor slab, and damp-proof courses
Drainage, before it's covered
Structural elements such as steel beams and roof structures
Insulation, before it's covered up
Completion, once the work is finished
The exact stages depend on the project. On jobs we project manage, booking these inspections is part of the programme, so the job doesn't stall waiting for a visit.
The completion certificate
When the work is finished and the final inspection is satisfactory, you should receive a completion certificate (or a final certificate from a private approver). Keep it safe with your planning documents, electrical certificates and any other competent person certificates. Solicitors routinely ask for these when a property is sold or remortgaged, and missing paperwork can cause delays.
Work that doesn't comply can lead to enforcement action and the cost of putting it right, so it's far better to get approval in place from the start.
Building Regulations FAQs
Do I need Building Regulations if I don't need planning permission?
Very often, yes. The two systems are separate, and permitted development projects such as many rear extensions and loft conversions still usually need Building Regulations approval.
Who is responsible for getting approval: me or my builder?
As the client, you are responsible for making sure the work complies, although your builder and designer also have duties. In practice, agree in writing who will make the application and book the inspections.
How long does Building Control approval take?
A full plans application takes several weeks to be checked, so build that into your timeline. Private approvers can sometimes move more quickly, but timings vary from project to project.
Is the Party Wall Act part of Building Regulations?
No. The Party Wall etc. Act 1996 is separate legislation covering work on or near shared walls and boundaries, and it may apply alongside Building Regulations.
Get your project off to the right start
Our process page explains how we take projects from design to completion, including approvals and inspections. To talk about your plans, call Cornish Building Company on 01208 816991 or contact us.
