At Kingdom Design & Build, we create high-quality house extensions with craftsmanship and care, handling everything from design to completion so you can complete your project with confidence
Extends your home into the garden, perfect for expanding kitchens, living rooms, or creating open plans.
Utilises the narrow alley beside your home, often transforming dark kitchens into bright, spacious areas.
Combines side and rear extensions to dramatically increase space and completely reshape the ground floor.
Adds two levels at once, increasing bedroom and downstairs space, often a cost-effective long-term solution.
Blends solid structure with glazed roofing—ideal for year-round entertaining, dining, or a light-filled retreat.
Builds above existing areas like a garage or single-storey space, without taking up additional garden space.
Taking on a house extension project can feel overwhelming. Finding the right trades, managing timelines, and keeping costs under control isn’t easy. At Kingdom, we make it easy by offering a fully managed service, handling everything from design to final completion.
No dealing with multiple contractors. Our experienced team manages the entire project, ensuring smooth communication and coordination.
A well-built garage conversion should do more than look great. We design with practicality in mind to make everyday living easier.
Choosing the right builder isn’t just about the final result. It’s about the experience along the way. We understand that House Extensions can be disruptive, which is why we do everything we can to make the process smooth and stress-free.
From keeping your home as tidy as possible to ensuring clear communication at every stage, we take care of the details so there are no surprises. With Kingdom, you can expect a well-managed house extension project, minimal disruption, and a space you’ll love at the end of it.
Explore some of our stunning house extension projects in Oxford.
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Here are some common questions about house extensions in Oxford.
Most single-storey extensions take around 4–8 weeks once construction begins (depending on the size). Add design, planning, and approval stages, and you're looking at 4–6 months from idea to completion. Double-storey builds take longer. The more complex the project, the longer the timeline, so factor in time for decisions, weather, and unexpected delays.
Not always. Many extensions fall under Permitted Development Rights, meaning no planning permission is needed—if you meet size and design limits. Rear extensions up to 6 metres (or 8 for detached homes) often qualify. But exceptions apply in conservation areas, flats, or if your home has been extended before. Always check with your local planning authority.
It depends on your location, the type of extension, and current market trends. As a rough guide:
A single-storey extension can add 5–8%
A double-storey extension may boost value by up to 12%
Adding a bedroom or a larger kitchen-diner often brings the biggest returns
Orangeries, open-plan layouts, and well-integrated spaces are especially attractive to buyers. To get an accurate picture, speak with a local estate agent before building—they’ll estimate the potential new value based on comparable properties. Kingdom Design & Build can then help you design with that value in mind, so every square metre works harder for your investment.
Costs vary widely. On average:
£1,800–£2,500 per m² for standard finishes
£2,500–£3,500 per m² for high-end or complex builds
So a 20m² extension might cost £36k–£70k+. This excludes design fees, VAT, and possible planning costs. A clear, itemised quote from your builder is essential.
Our team at Kingdom Design & Build offers transparent quotes and can help optimise your budget without compromising on quality.
Yes. Good design and structural safety are essential. Whether you're planning a creative open-plan layout or removing load-bearing walls, Kingdom Design & Build provides in-house architects and structural engineers to ensure your plans are both beautiful and compliant.
Not necessarily. Many families live at home throughout, especially for rear or side extensions. But expect dust, noise, and limited access to key areas like the kitchen. For major renovations or if your water/electricity is shut off for long periods, temporary accommodation might be wise.
Yes, all of our work is backed by a workmanship guarantee, ensuring quality and durability. We also ensure that all work meets current building regulations.
Yes, but additional extensions may require full planning permission depending on past works. Our planning team can check your home’s extension history and advise on your options—ensuring everything stays compliant from the start.
If resale value is a priority, speak with a local estate agent before building. They can help you understand the potential uplift in your property’s value if you increase its size. In most cases, adding a bedroom or creating a larger kitchen-diner makes a home more appealing to buyers. Orangeries are also a strong investment—they combine extra space, natural light, and beautiful design, making your home more desirable.
