House Extensions
House Extensions Built to Fit Your Home and Lifestyle
Extending your house can provide the extra space you need and could cost less than moving home. It is also an opportunity to create a space that works for you, be that a larger kitchen with connection to your garden, a family room, or more bedrooms.
At Keystone Homes, we build a variety of house extensions for homes across Surrey, Sussex, Hampshire and South London. We work on single storey extensions, double storey extensions, rear extensions, side return extensions and spaces that make your home work for you.
As a family-run building company, we provide the highest standards of workmanship, detailed project management and clear communication to deliver home extensions that fit your home, needs and lifestyle.
Home Extensions Designed to Enhance the Way You Live
Many home extensions are driven by the need to solve a problem. You may want more space for your growing family, a larger kitchen, a space to work or just need a better layout to make your home work for you.
Keystone Homes create house extensions that are practical, beautifully finished and cohesive with your property. We take time to understand what you need and want to achieve before we start work. A detailed understanding of our client’s vision and the problems they need to solve is the key to delivering a great home extension.
We support clients through every stage of their build, with clear communication, professional project management, an eye for detail and innovative solutions.
Our aim is always to create new spaces that meet our client’s needs and feel built to last. Your completed extension should not feel like an afterthought. It should feel like seamless part your home.
Planning Permission, Building Regulations and Local Concents
Careful and thorough planning is the key to every successful project. Some house extensions may fall within permitted development rights. Others may need planning permission or special consents from the local authority.
Keystone Homes will work in conjunction with your architect, structural engineer, designer and local authority at every stage. We can help you understand the practical steps involved and ensure that the project runs smoothly, minimising stress and costs.
This is especially helpful for homes in Surrey and Sussex conservation areas, older properties and listed buildings or homes with previous alterations. Good advice early on can help avoid unnecessary delay, mitigate costs, and keep your project moving in the right direction.
The Right Builder for Your House Extension
Choosing the right builder will make or break your project. The quality and success of your house extension hinges on this important choice.
At Keystone Homes, we take pride in delivering quality workmanship, tidy working practices, minimising problems and providing clear communication. We know that building work at home is disruptive, and we do everything we can to make the process straightforward and as stress free as possible.
Clients choose Keystone Homes because we provide:
- Clear communication throughout the project
- Professional project management
- Skilled and experienced tradespeople
- High standards of craftsmanship
- Respect for your home and neighbours
- Honest and practical advice
From initial consultation through to delivering your completed project, our aim is to always build extensions that add space, quality and lasting value to your home.
Frequently Asked Questions: Extending Your Home
Do I need planning permission for a house extension in Surrey?
You will require planning permission for house extensions in Surrey if your plans do not fall within permitted development rights. Here is a summary of current (2026) Permitted Development (PD) rules:
- Permitted Development rights generally apply to houses, but not to flats or maisonettes.
- An extension cannot usually be built in front of the main elevation of the house or beside an elevation that faces a road.
- For most homes, a single-storey rear extension can project by up to 4 metres from a detached house or 3 metres from a semi-detached or terraced house.
- A larger rear extension may be allowed through the prior approval process. The maximum depth is 8 metres for detached houses and 6 metres for other houses. Neighbouring properties will be consulted before the council makes its decision.
- Single-storey extensions can be up to 4 metres high. Where the extension is within 2 metres of a property boundary, the eaves will usually be limited to 3 metres.
- A side extension must have one storey, be no more than 4 metres high and measure no more than half the width of the original house.
- Two-storey rear extensions are usually restricted to a depth of 3 metres. They must also be at least 7 metres away from the boundary at the end of the rear garden.
- Extensions, sheds and other additions must not take up more than half of the land around the original property.
- Materials used on the outside of the extension should closely match the appearance of the existing house. Balconies, raised platforms and verandas are not normally included within Permitted Development rights.
- Tighter controls may apply to listed properties and homes in conservation areas or the Surrey Hills National Landscape. Local Article 4 Directions and conditions attached to earlier planning permissions can also remove Permitted Development rights.
- Domestic planning matters in Surrey are dealt with by the relevant borough or district council. Homeowners can apply for a Lawful Development Certificate if they want formal confirmation that planning permission is not required.
- Building Regulations approval may still be necessary, even when an extension qualifies as Permitted Development. The work may also need to comply with the Party Wall Act and other legal requirements.
Should your house extension or renovation project require panning or special permissions, we can work with your architect or planning adviser to help the project move forward efficiently.
Do house extensions in Surrey and Sussex need building regulations approval?
Building regulation approval is required for new builds, most house extensions, structural alterations, new window and door openings, and if changes are made to core services such as electrics, heating systems, gas and water supplies. Keystone Homes will undertake all aspects of your building works in conjunction with your building inspector and advise where Building Regulations approval may be required.
Can you build extensions in conservation areas or on older homes?
Yes. Keystone Homes has experience working on older properties and character homes in areas with restrictions. Extensions in conservation areas or on listed buildings require a considered and sympathetic approach, with an understanding of the correct materials and methods. To ensure your project runs smoothly, the correct permissions must be in place, and your contractor should have knowledge of your type of home and in dealing with the processes and restrictions associated listed buildings and conservations areas. Keystone Homes can help you to navigate this process.
Are conservation areas in Surrey and Sussex subject to special building restrictions?
Yes, conservation areas in Surrey and Sussex are subject to strict legal building restrictions designed to protect their historic and architectural value. Permitted Development (PD) rights for properties in Surrey conservations areas, are severely reduced or completely removed but are likely to fall under local Article 4 Directions.
Implementation of Article 4 Directions falls to local district and borough councils. It is important that you contact the relevant local authorities and take time to fully understand the regulations that affect your local area and property before planning or starting any works.
Article 4 Directions (Local Restrictions)
Article 4 Directions are locally enforced regulations that replace permitted development rights. This may require full planning permission for many or all external and structural or major alterations to your home. The precise restrictions will vary in Surrey and Sussex buy area and local authority. Examples of minor changes and works that may require planning permission include:
- Changing front doors
- Replacing traditional timber sash windows with modern UPVC units
- Painting unpainted brickwork, or changing exterior, cladding or colour
- Installing satellite dishes or solar panels on roof slopes facing a highway
There are also controls on demolishing all or parts of existing properties, removing or significantly altering boundary walls and fences, and tree preservation rules to consider. We strongly advise working with an experienced planning consultant and builder if you are considering extending or renovating a listed property or house in Surrey and Sussex conservation areas before starting detailed planning.
Which local areas do you cover for house extensions?
We build house extensions across Surrey, Sussex, Hampshire and South London. This includes homes close to us around Chiddingfold, Godalming, Guildford, Haslemere and all local villages.
Can you build single storey and double storey extensions?
Yes. We build all types of house extensions including single storey, double storey extensions, rear extensions, side return extensions and kitchen extensions. If you can design it, we can build it for you. Please contact us to discuss your project.
Can you work with my architect or structural engineer?
Yes. We have extensive experience working alongside architects, structural engineers and designers on house extensions and renovation projects. We ensure great communication to ensure all aspects of your home extension are clear, accurate and well managed from start to finish.
Will my extension need structural calculations?
Many house extensions require structural calculations and engineers. If you are moving walls or creating new openings, structural beams and supports will often be required. Precise calculations are usually prepared by a structural engineer and passed by planners before work begins.
How do I get a quote for a house extension?
You can contact Keystone Homes by telephone, email or through our website contact form. We will be happy to discuss your plans, visit site, and provide you with a comprehensive quote and works plan if you are interested in us undertaking your project. Please contact us for a chat with no obligation.
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We would be delighted to make your home extension a reality, please get in touch to discuss your project.