Extensions

The most common type of extension and the most straightforward in planning terms. A single-storey rear extension adds usable ground floor space, typically to the kitchen or living area, and in many cases falls within permitted development without needing a full planning application. Size, height, and proximity to boundaries all affect whether permitted development applies to your property.

A wraparound combines a rear and side return extension to create the largest possible ground floor footprint. These projects almost always require planning permission and more complex structural work, but the result is a significant transformation of the ground floor layout. They work particularly well on Victorian terraces and semi-detached properties where the original ground floor is broken into several small rooms.

A well-designed single-storey extension gives you space where you need it without the complexity of building above. Roof design, natural light, and how the extension connects to the existing property are the critical decisions. A flat roof with rooflights, a pitched roof that matches the existing property, or a glazed roof are all options with different cost and planning implications.

Building over two floors maximises the space gained from the footprint. A double-storey extension almost always requires planning permission and involves more structural complexity, particularly at the junction with the existing structure. The cost per square metre is lower than a single-storey extension because you’re sharing foundations, external walls, and roof across two floors. For families needing both additional bedroom space and ground floor space, a double-storey extension often represents the best value.

Many Victorian and Edwardian terraced and semi-detached properties have a narrow side return, the unused passageway that runs alongside the kitchen. Infilling this space can meaningfully increase ground floor square footage without extending into the garden. The structural challenge is bridging the span between the existing rear wall and the new side wall, which typically requires a steel beam. Done well, a side return transforms a cramped kitchen into a properly usable space.