Extensions
Extensions
Types of House Extensions in the UK
Building a house extension is an exciting way to expand your living space and add value to your home. Once measurements are taken, designs are approved, and planning permissions are granted, the real transformation can begin. But before you start, it’s important to understand the different types of house extensions available — each with its own purpose, cost, and building requirements.
Main Types of House Extensions
1. Porches
A porch is a small extension usually built at the front of a house, though it can also be added to the side or rear. Typically constructed from brick walls, columns, windows, and a door, larger porches may include plastered interiors, lighting, and electric sockets.
Most porches do not require planning permission as long as they’re separated from the main house by an internal door, are unheated, and meet size limits. However, if you plan to install electrics, you’ll need to:
Have the work inspected by the local building control department, or
Hire a Part P registered electrician.
2. Conservatories
Conservatories are light-filled structures typically made of uPVC, timber, or aluminium. They’re perfect for creating a bright, garden-facing living space. Whether planning permission is required depends on size and design, but most conservatories still need to comply with building control regulations.
3. Sunrooms
A sunroom is similar to a conservatory but built with solid walls and a solid roof, providing better insulation and durability. Sunrooms let in plenty of natural light while maintaining warmth throughout the year. Because of their complexity, they usually cost more and require both an architectural design plan and building control approval.
4. Single-Storey House Extensions
Single-storey extensions are built onto one level of your home, often to the rear or side. They are perfect for adding:
A new kitchen or dining area
A home office or playroom
An extra bedroom or utility room
These extensions usually need building control approval, though planning permission may not always be necessary. Key considerations include roof design, drainage, and how the extension integrates with the existing structure.
Single-storey rear extensions are especially popular, as they can open up your kitchen to the garden, creating a seamless indoor–outdoor flow and adding significant property value.
5. Double or Multi-Storey Extensions
A two-storey extension allows you to expand both the ground and upper floors of your home — ideal for adding extra bedrooms, bathrooms, or large open-plan areas.
While this type of project adds substantial space and value, it is also more expensive and complex than single-storey builds and almost always requires planning permission. It’s best suited for detached or semi-detached homes with available side or garden space.
6. Wrap-Around Extensions
A wrap-around extension combines a side return extension and a rear extension to form an L-shaped structure. This design dramatically increases floor space and offers flexibility for open-plan living areas, larger kitchens, or new guest rooms.
However, these projects can be more disruptive and design-intensive, requiring careful planning to maintain balance with your home’s existing architecture. Wrap-around extensions can also significantly increase your home’s value when done well.
7. Over-Structure Extensions
An over-structure extension is built above an existing space, such as a garage or kitchen. It’s an efficient way to create extra rooms — for example, a master suite with an en-suite bathroom — without expanding your home’s footprint.
However, before starting, it’s essential to check the existing foundation strength. Many garages are built with single-skin brickwork, which often isn’t strong enough to support a new level. Reinforcements like new foundations or steel beams may be required, adding to the cost.
Building control approval is mandatory for this type of extension.
Common Roof Extension Styles
When extending your home, you can choose from various roof designs to complement your existing structure:
Flat Roof
Hip Roof
Mansard Roof
Dormer Roof
Butterfly Roof
Hip and Valley Roof
Each roof style affects the look, cost, and energy efficiency of your extension, so professional design advice is recommended.
Final Thoughts
Whether you’re adding a small porch, a bright conservatory, or a full double-storey extension, each type of home extension offers unique benefits. Proper planning, budgeting, and compliance with UK building regulations are key to achieving a successful, value-adding project.
About the Author
Clara Annesley is an interior design and construction writer with a BSc (Hons) in Architectural Design Technology from the University of West London. She specialises in residential construction, health and safety, architectural design, and cost guides for renovation and remodelling projects.