In London, space is precious and house prices are always on the rise. That’s why expanding your home is often smarter than moving. A single-storey extension doesn’t just give you more room-it can make your home work smarter for you and increase its value, all without the stress of relocating. Whether you dream of a sleek new kitchen, a sun-filled living area, or extra space for the family, planning your extension carefully is the key to success.
Think of this blog as your go-to guide for planning a single storey extension in London. We’ll walk you through every step-from the early prep, to getting the right permissions, to nailing the design, and finally figuring out the costs. And don’t worry, our expert extension architecture team is here to help every step of the way, so you’ll never feel lost in the process.
Planning a One-Storey Extension? Here’s How the Experts Do It
At Extension Architecture, we’ve designed and built hundreds of single-storey extensions across London, helping homeowners create seamless, stylish, and hassle-free spaces. Having worked in the city for years, we know exactly what it takes to make a project successful-whether it’s a tricky site with limited access, a property with heritage restrictions, or simply getting the most out of every bit of available space.
Our surveyors take care of everything-from the very first sketches to the full planning submission and building regs drawings.
Every extension we design is tailored to fit your needs, your lifestyle, and your future plans. We always keep practicality and budget in mind.
Whether it’s a Victorian terrace in Kensington or a semi-detached home in Wandsworth, we make the process simple. And more than that, we make it a project that adds real value to your home.
Don’t Start Without Knowing These Key Extension Considerations
Before committing to a single-storey extension, clarify your goals:
- Purpose of the space: Bigger kitchen, brighter living room, home office, or downstairs bathroom?
- Orientation & light: South-facing extensions enjoy natural sunlight, while north-facing may need extra lighting.
- Integration with your home: Will it open to your garden, wrap around a side return, or extend the full rear?
- Neighbours & regulations: Party wall agreements and overlooking concerns are common in London-consult early to avoid disputes.
Then, have a look at the orientation and layout of your property. Extensions along the south will have more natural light and having the extension along the north may need more artificial lighting, and heating. Consider how your extension will be with your current layout, will it open out onto the garden, wrap around the side return or run the full length of the rear?
You will also have to consider the impact the extension will have towards your neighbours. In London, premises tend to be adjacent with each other and this makes party wall agreements and overlooking matters present very usual factors. Seeking the advice of the professionals and the neighbours earlier can avert the risks that come along the way in terms of impounds and conflicts.
Budget Smarter: Costs You Need to Know Before Your Extension
An extension by architects in London can cost as little as a few thousands and as much as tens of thousands of pounds, depending on size, materials and/or finishes and on-site challenges. Generally, you may pay between £1,800-£3,000 in terms of per square metre cost. An average rear extension of 20-30 sqm can also vary between £36000 to £90000 without VAT and professional charges.
There are also the charges on planning, architectural drawings, structural engineering and building regulations approval. Do ensure that you have a buffer of at least 10-15% of the overall budget on expendable items such as resolving the problem of drainage or improving the electrics.
We at Extension Architecture work with clients to plan their budget in detail before anything starts. The way we quote is very transparent, so you won’t face random extra costs later on. Plus, we can advise on value engineering to help you choose smarter options and stretch your money further.
Our Design Secrets: Making Your London Extension Stylish & Functional
London houses are noted to have a diversity in architecture and this is where we excel at. Where housing types are concerned, we are sensitive to the unique characteristics of Georgian townhouse, 1930s semi and contemporary flat and mews houses. We are context-sensitive, yet short of creativity in our design.
When designing single-storey extensions, our focus is on maximizing space, light, and flow. It’s not just about adding a new room-it’s about how the extension seamlessly blends with the rest of your home and the outdoor space. That’s why we often incorporate tall glass windows, skylights, and sliding or bi-fold doors, creating bright, airy spaces that feel open and inviting.
We also know that a beautiful extension should not be lazy. That is why carrying out each project we consider storage, acoustics and energy efficiency. Through the combination of the architectural magic with the technical exactness, we design the rooms which can be both practical and inspirational.
