Thinking of upsizing in 2025? Before you list your home, consider the smarter, more valuable alternative: a bespoke house extension built around your needs and lifestyle.
At Home Improvements & Construction Ltd (HICL), we believe that improving your property is often far wiser—and more rewarding—than moving. This summer, a thoughtfully designed extension could transform your current house into your forever home. From planning to final polish, we handle every aspect as your trusted turnkey construction company in South-West London.
In this guide, we walk you through everything you need to know about starting a home extension project—covering design, planning permission, costs, and the real benefits of staying put.

Why Moving Isn’t Always the Answer
House prices, stamp duty, legal fees, removals, and the emotional stress of uprooting a family—moving house in London can cost well over £50,000 before you’ve even unpacked. For many families and professionals in areas like Kingston, Surbiton, Wimbledon, and Richmond, the space they need is already under their roof or just beyond it.
That’s where we come in. Whether you're considering a rear kitchen extension, side-return, or wraparound design, we create functional, future-proof extensions that let you:
- Stay in the area you love
- Increase your property value
- Avoid moving stress and costs
- Enjoy tailored design suited to your lifestyle
What Type of House Extension is Right for You?
The right extension depends on your goals, lifestyle, and property layout. At HICL, we specialise in bespoke solutions designed to maximise both space and value.
Popular choices among our South-West London clients include:
- Rear extensions: Ideal for kitchen-diners and open-plan living
- Side return extensions: Perfect for Victorian terraces with unused alleyways
- Wraparound extensions: Combine side and rear for maximum ground floor space
- Double-storey extensions: Add bedrooms, bathrooms, or home offices upstairs
Modular or contemporary garden rooms: Fast-track builds for studios or guest annexes
Click here to view our recent home extension project in Kingston.
Planning Permission & Regulations: What You Need to Know
You might not need full planning permission. Under Permitted Development Rights, many single-storey extensions can go ahead without a full application.
However, you'll need planning consent if:
- Your extension exceeds specified size limits
- You live in a conservation area
- Your property is a flat or maisonette
At HICL, our in-house planning specialists handle all applications, liaise with local authorities, and ensure your project aligns with the Building Regulations 2025 update.
Common planning considerations include:
- Impact on neighbours (especially boundaries and overshadowing)
- Roof heights and materials
- Conservation area constraints (especially in Richmond and Wimbledon)
Design Inspiration for Summer 2025
Looking for ideas? Here are the design trends shaping house extensions this summer:
- Open-plan kitchen-living spaces with bi-fold doors
- Velux-style rooflights to maximise light
- Sustainable materials and eco-friendly insulation
- Smart home upgrades like lighting and underfloor heating
- Natural textures and biophilic design (bringing the outdoors in)
We provide full design & build services, meaning your ideas become reality with a single point of contact. Whether you want a classic extension or a sleek, modern twist, our architects and interior designers are ready to help.
What Does a House Extension Cost in 2025?
We know budget is key. At HICL, we offer transparent pricing and fixed-cost contracts so there are no surprises.
As a rough guide:
- Single-storey extension: £70,000–£110,000+
- Double-storey extension: £110,000–£180,000+
- Wraparound extensions: From £120,000+
This includes:
- Design and architectural drawings
- Structural engineering
- Planning applications
- Full construction and finishing
We also offer fixed-price loft conversions, dormer extensions, and turnkey attic conversions for homeowners looking to unlock hidden space upstairs.
Click here to view one of our recent Whole House Rebuild projects in Watford.
How Long Will It Take?
A house extension can typically be completed in 10 to 16 weeks, depending on complexity, weather, and size.
Our experienced project managers ensure everything runs smoothly and to schedule. We specialise in efficient summer builds, meaning your new space is ready before autumn school starts.
Timeline breakdown:
- Design & permissions: 4–8 weeks
- Build & fit out: 10–16 weeks
- Final inspection & sign-off: 1 week
The Long-Term Benefits of Extending
Still debating whether to move or improve? Here’s why an extension pays dividends:
- Add 15%+ to your property value (especially in Wimbledon, Richmond, and Esher)
- Customise your living space to suit growing families or multigenerational needs
- Increase energy efficiency with upgraded insulation and glazing
- Create rental or Airbnb opportunities with self-contained annexes
Many of our clients in Surbiton, Twickenham, and Guildford have used extensions to future-proof their homes for children, ageing parents, or changing work patterns.
Why Choose HICL for Your Extension Project?
With over 20 years of experience, we’re more than just extension builders—we’re a full-service construction partner. Our turnkey model covers:
- Design & architectural planning
- Structural calculations & building control
- On-site project management
- Skilled tradespeople & certified workmanship
- Transparent timelines and fixed-price contracts
We’ve helped hundreds of families in South-West London and Surrey improve instead of move—and we’re ready to help you this summer.
Whether you’re in Cobham or Chessington, Raynes Park or Richmond, we provide trusted, elegant solutions tailored to your needs.
Ready to Begin? Let’s Talk
Moving is expensive and exhausting. This summer, improve your home with HICL instead.
Visit our revitalised Surbiton office for tailored advice, design inspiration, and coffee with a team who genuinely care about bringing your vision to life. From the first sketch to final finish, we’re with you every step of the way.
Let’s turn your house into your dream home.
Contact Home Improvements & Construction Ltd today.
Like what you see? Reach out to our experienced team, located in Surbiton.
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