When homeowners in Birmingham think about extending their property, planning permission is often the first thing that comes to mind. But Building Regulations approval, a separate and equally important requirement, applies to the vast majority of extension projects and sets out the technical standards your build will need to meet. Understanding how Building Regulations affect your extension from the outset helps to avoid costly surprises during or after construction.
What Are Building Regulations?
Building Regulations are a set of minimum technical standards that ensure buildings are safe, healthy, and energy-efficient. In England, they are set out under the Building Regulations 2010 and the associated Approved Documents, which provide guidance on how to meet the requirements of each part. They are administered locally, in Birmingham, by Birmingham City Council’s Building Control service, or alternatively by a private Approved Inspector.
Unlike planning permission, which is concerned with whether something should be built, Building Regulations are concerned with how it is built. Approval is required before work begins (or, in some cases, notified within a set period of the work starting), and inspections are carried out at key stages of the build.
Key Parts of the Regulations Relevant to Extensions
Several parts of the Building Regulations are commonly relevant to residential extension projects:
- Part A (Structure) – Ensuring the extension is structurally sound, including foundations appropriate to the ground conditions and any structural alterations to the existing building.
- Part B (Fire Safety) – Requirements relating to means of escape, fire detection, and the spread of fire. Relevant where an extension creates or alters habitable rooms or escape routes.
- Part C (Site Preparation and Resistance to Contaminants and Moisture) -Ensuring the extension is adequately protected from ground moisture and any site contamination.
- Part F (Ventilation) – Adequate ventilation for habitable rooms, kitchens, and bathrooms within the extension.
- Part L (Conservation of Fuel and Power) – Energy efficiency requirements for the new extension and, where works affect existing fabric, for those elements too. Under the current 2021 edition of Part L, the standard expected for new extensions is relatively demanding, with requirements for U-values, thermal bridging, and air permeability.
- Part P (Electrical Safety) – Any new electrical installations within the extension must comply with BS 7671 and be carried out by a competent person or notified to Building Control.
The Building Regulations 2010 and Recent Updates
It is worth noting that Building Regulations are periodically updated. The 2021 revisions to Part L introduced more stringent energy efficiency requirements, and further changes are anticipated as the Government progresses its Future Homes Standard, which is expected to set even higher standards for new residential construction in the coming years. Working with an architect who is current with these requirements ensures your project is designed to comply from the outset, rather than requiring modifications once Building Control has reviewed the proposals.
Inspections and the Completion Certificate
During the build, a Building Control inspector will carry out site visits at agreed stages, typically including the foundations, damp-proof course, structural frame, insulation, and final completion. It is your responsibility (or your contractor’s) to notify Building Control at the appropriate stages; uninspected work may need to be uncovered for inspection.
On satisfactory completion, Building Control will issue a Completion Certificate. This document is important: it provides formal confirmation that the work has been carried out in compliance with the Regulations, and mortgage lenders and buyers will typically expect to see it when a property is later sold.
Does a small extension always need Building Regulations approval?
Not always, but the exemptions are narrow. A detached single-storey outbuilding under 30 square metres with no sleeping accommodation may be exempt, for example. However, most extensions to a dwelling, including attached single-storey rear extensions, will require approval. If in doubt, it is safer to submit a Building Regulations application than to assume an exemption applies.
What happens if work is done without Building Regulations approval?
Carrying out work that requires Building Regulations approval without obtaining it is a breach of the Regulations. The local authority has the power to require works to be altered or removed if they do not comply. More practically, the absence of a Completion Certificate will likely cause difficulties when you come to sell the property. A regularisation application can sometimes be made retrospectively, though this is not available for all types of work.
Can my builder deal with Building Regulations on my behalf?
Yes, in practice many contractors manage the Building Regulations notification process. However, the legal responsibility for compliance rests with the person carrying out the works and, ultimately, the property owner. Having Brophy Riaz and Partners involved, particularly for more complex projects, provides an additional layer of oversight and helps to ensure that the design is buildable to the required standard before work starts on site.
About Brophy Riaz and Partners
Brophy Riaz and Partners are a RIBA Chartered architectural practice based in Birmingham, with over 28 years of experience helping homeowners across the West Midlands bring their residential projects to life. In that time, they have completed more than 3,000 projects, from modest extensions to full-scale home transformations, building a reputation for thoughtful design, practical guidance, and a genuine understanding of the local built environment.
Their work spans a wide range of residential projects across Birmingham and the surrounding area, and their team is well-versed in the specific planning and design considerations that come with the region’s varied housing stock, including its wealth of Victorian and Edwardian properties.
Whether you are at the very start of thinking about a project or ready to move forward, Brophy Riaz and Partners offer free, friendly advice with no obligation.