Is It Safe to Build a Basement Under Your Garden? Here’s What Experts Say
July 29, 2025
Loft Conversion Planning Permission: What London Homeowners Need to Know
September 25, 2025
Thinking about extending your London home? Whether you’re leaning towards a London single-storey extension or considering the added space of a double-storey option, making the right choice can have a lasting impact on your property value, lifestyle, and budget. With house prices and space at a premium, extending your property is a smart move, but it's vital to get it right from the start.
In this guide, we break down the key differences between single and double-storey extensions, the estimated single-storey extension cost, and why choosing trusted extension builders near London, like MBT Group, is crucial.
Why Consider a Home Extension in London?
Property extensions have become increasingly popular across the capital, as homeowners seek smart ways to increase their living space without the hassle and cost of moving. With limited outdoor space in many London neighbourhoods, choosing between a side return, rear, or even wraparound extension requires expert planning and design.
A well-built extension not only boosts functionality but can dramatically improve your home’s resale value. If you’re torn between a single or double-storey extension, here’s what you need to consider.
Single Storey Extensions: Smart, Simple and Stylish
A London single-storey extension is typically the go-to choice for those looking to:
- Create an open-plan kitchen-diner
- Add a home office or guest room
- Extend into the garden or side alley (side return extension London)
- Avoid complex planning permission or structural changes
At MBT Group, we specialise in delivering single-storey extensions that complement your home’s design, enhance energy efficiency, and maximise every inch of space.
For an in-depth breakdown of London house extension cost, explore our detailed blog:
Guide to Single Storey Extension Cost in London
Double Storey Extensions: Twice the Space, More Value
If you’re thinking long-term or planning for a growing family, a double-storey extension might be the smarter investment. With a second level, you can add multiple bedrooms, bathrooms or even a second living area, all without increasing your home’s footprint.
However, a double-storey build will:
- Require more extensive planning permission
- Be a higher upfront investment
- Demand longer construction timelines
Yet, the return on investment is often greater, especially in sought-after London boroughs.
Side Return Extensions in London: The Underrated Game-Changer
Side return extensions are ideal for Victorian or Edwardian terraced homes that have narrow, underused alleyways alongside them. With clever design and structural work, this space can be transformed into a stunning new kitchen, dining room or utility space.
At MBT Group, we’ve helped dozens of homeowners in London unlock the potential of their side alleys with innovative side return extensions. Learn more about what makes a great property maintenance team in London by reading:
What Makes a Great Property Maintenance Team in London?
What Does a Single Storey Extension Cost?
On average, a single story extension cost in London can range from £1,800 to £2,500 per m², depending on materials, finishes and complexity. Expect to pay around:
- £30,000–£50,000 for a basic 4m x 5m rear extension
- £50,000–£80,000 for high-end finishes, bi-fold doors, or kitchen installations
Want to future-proof your investment? Dive into our popular blog:
Is It Expensive to Build a Basement in the UK?
Choosing the Right Extension Builders Near London
The success of your project depends largely on the team you choose. At MBT Group, we pride ourselves on being one of the most trusted extension builders near London. Our team combines architectural vision with skilled craftsmanship to deliver on time, on budget, and above expectations.
Our services include:
- Consultation and design
- Planning permission support
- Full construction management
- Aftercare and snagging
Explore how we go beyond expectations by reading:
How to Build a Shed That Lasts – A Step-by-Step Guide
Need Something More Bespoke?
If you’re not just considering an extension but thinking of transforming your attic into a bedroom or home office, our team also specialises in loft conversions. Discover unique inspiration in our most-read blog:
👉 Stylish Loft Conversion Ideas for London Homes in 2025
This is the heading
Choosing between a single or double storey extension ultimately comes down to your:
- Available budget
- Space constraints
- Future plans
- Local planning regulations
A single-storey extension is ideal if you want quicker completion, lower cost, and seamless garden access. A double-storey extension suits those needing more space without compromising on the outdoor area.
Whatever you choose, working with a team that understands London homes, council planning, and modern design is non-negotiable. That’s where MBT Group comes in.
Ready to Build Your Dream Extension?
Whether you’re planning a side return extension in London, a modest single-storey build, or a bold double-level addition, MBT Group is here to help. Our experienced team will guide you through the process, from planning to completion.
