Thinking of taking on an extension project? Anna-Marie DeSouza’s guide to securing consent highlights everything you need to know to get a successful result

Philip Wadge Architecture gained consent for this stunning extension with a Japanese-influenced roof. To boost the chances of success, the planning application demonstrated how modern materials and contemporary design can work to break down barriers between house and garden for a harmonious finish.

There are numerous reasons for extending your property, from building a new kitchen to allowing for an office, or even creating additional space for a family member. Along with loft conversions, extensions are the most popular home improvement project in the UK – and it’s no surprise, as embarking on this kind of project can completely transform the way your property is used, not to mention increase its value.

Permitted development (PD) rights exist that enable certain types of home extension without having to apply for full planning, as long as specific conditions are met. For example, only half the area of land around the original house can be covered by extensions (or other buildings), and it cannot be higher than the tallest highest part of the existing roof. These rights have continued to evolve; in England, for instance, the size limits have doubled for certain types of addition, and since 2020 there has been a fast-track system in place for two-storey home extensions.

Limitations

Bear in mind that PD doesn’t cover all types (and sizes) of extension. If you are looking to create something that might fall outside of the rights, then it is likely that a full application for householder planning permission will be required. It is always recommended that you verify what you are and aren’t allowed to build with your local authority. “I always stress how important it is to check your project definitely falls under permitted development,” says Liz Alexander, Head of Planning at Octagon. “PD rights can be removed or altered, and whilst it’s easy to assume your project will benefit from these, it’s crucial to confirm this to avoid being in breach of planning. If your project does fall under PD, I suggest applying for a Lawful Development Certificate (LDC). This is applied for via the council and provides confirmation that your extension is permitted.”