★★★★★
“From the first call, everything was explained clearly. We had no idea where to start with planning, but they guided us through every step. The advice alone saved us from making costly mistakes.”James R. West London homeowner
House Extensions London Bespoke Home Extensions & Additions
Transform your London home with a design-led extension managed from first consultation through planning, structural calculations, building regulations, project management and build.
Get Free Quote Call NowFreeinitial extension review
Londonplanning and property knowledge
Design + Buildclear route from idea to handover
Clear Adviceplanning, structure and build guidance
Bespoke House Extension Builders in London
Create more space, improve your layout and add long-term value without the cost and stress of moving. House Extensions London helps homeowners plan, design and build rear extensions, kitchen extensions, side return extensions, wraparound extensions, single storey extensions and double storey extensions across London.
London Extension Specialists
We understand Victorian terraces, Edwardian homes, 1930s semis, conservation areas, tight access, party wall matters and borough planning requirements.
Design, Planning & Build Support
From the first survey to drawings, planning guidance, structural calculations, building regulations and construction, your project has a clear route forward.
Free Initial Quote
Send your postcode, photos or drawings and we will advise on the best extension type, likely planning route and next steps.
Add Space & Value to Your London Home
Book a free initial review and find out whether a rear, side return, wraparound, kitchen or double storey extension is best for your property.
Our London House Extension Services
Every extension is different. We help you choose the right option for your home, budget, planning position and long-term lifestyle.
Rear & Wraparound Extensions
Open up the back of your home with a light-filled kitchen, dining and living space that connects beautifully to the garden.
Side Return Extensions
Make use of narrow unused side space, especially in London terraced homes, to create a wider and brighter ground floor.
Double Storey Extensions
Add valuable space upstairs and downstairs, ideal for larger kitchens, extra bedrooms, bathrooms or growing families.
Kitchen Extensions
Create a modern open-plan kitchen with rooflights, glazed doors, better storage and a stronger connection to the garden.
Single Storey Extensions
A practical way to add everyday living space while improving layout, natural light and property value.
Loft Conversions
If building upwards is the better option, we can also help with loft conversion routes for bedrooms, offices and bathrooms.
Side and Rear Extensions
Combine side and rear space for a bigger transformation with stronger flow, better storage and more usable floor area.
Flat Roof Extensions
A clean, contemporary choice for London homes, often paired with skylights, roof lanterns and wide-format glazing.
From Concept to Completion
A clear process reduces stress and helps you understand exactly what happens before, during and after the build.
1
Free Consultation
We discuss your ideas, budget, property type, postcode, access and the best extension route for your London home.
2
Design & Feasibility
We review layouts, natural light, structure, drainage, party wall risk and whether your project is likely to need planning permission.
3
Planning & Permissions
We guide you through planning permission, permitted development and lawful development certificates.
4
Structural Calculations
We coordinate structural calculations and building regulations so the extension is safe, compliant and buildable.
5
Build & Project Management
Your extension is managed with clear communication, organised trades and practical site control through our project management support.
6
Completion & Handover
Final checks, snagging, finishing details and handover so your new space is ready for everyday use.
Planning Permission, Permitted Development & Building Regulations
London extensions often depend on the borough, property type, conservation rules, previous alterations, neighbours and structural requirements.
Permitted Development
Some single storey rear extensions may be possible without full planning permission, but flats, maisonettes, listed buildings and many designated areas are more restricted.
Planning Applications
Larger rear extensions, side extensions, two-storey extensions and homes in sensitive areas may need a formal planning application or prior approval.
Building Regulations
Most extensions need approval for structure, insulation, drainage, ventilation, fire safety, electrics and overall compliance.
Party Wall Matters
Many London homes share boundaries. If the work affects a neighbouring wall, boundary or excavation zone, party wall notices may be required.
House Extension Costs in London
Costs vary depending on size, specification, glazing, access, foundations, structural work, kitchen finish, bathrooms and planning requirements. The figures below are guide starting points only.
| Extension Type | Indicative Starting Budget |
|---|---|
| Single storey rear or side return extension | From around £35,000 |
| Kitchen extension | From around £40,000 |
| Wraparound extension | From around £60,000 |
| Double storey extension | From around £80,000 |
For an accurate quote, we need to review your property, drawings, measurements, access, structural requirements and finish level.
Ready to Extend Your London Home?
Get clear advice before spending money on drawings, planning or builders. Start with a free initial review.
Book a Free SurveyWhy Choose House Extensions London?
The right extension builder should reduce risk, explain the planning route clearly and give you confidence before you invest in drawings or construction.
Clear Guidance From Day One
We help you understand what’s possible for your property before you spend money on drawings, planning or builders.
London-Focused Knowledge
Every borough is different. We guide you through planning, permitted development and realistic options for your home.
Structured Design & Build Approach
From idea to completion, we outline a clear route so you know exactly what happens at every stage of your extension.
Practical, Straightforward Advice
No jargon, no overpromising — just clear recommendations based on your goals, budget and property.
✔ Free initial consultation
✔ No obligation advice
✔ Speak directly with decision-makers
✔ Clear next steps for your project
Reviews
Real feedback from London homeowners who gained clarity, avoided costly mistakes, and confidently moved forward with their extension projects.
Frequently Asked Questions About House Extensions in London
How much does a house extension cost in London?
Costs depend on size, specification, access, structural work, glazing, kitchen or bathroom fit-out and finish level. Small single storey extensions may start from around £35,000, while larger wraparound and double storey extensions usually cost more.
Do I need planning permission for a house extension?
Some extensions can use permitted development, but many London properties need planning permission because of size, location, conservation areas, flats, maisonettes or previous alterations.
What is permitted development?
Permitted development allows certain home improvements without a full planning application. It has strict rules, so we always check property type, size limits, previous extensions and local restrictions first.
Do I need building regulations approval?
Yes, most house extensions need building regulations approval for structure, insulation, drainage, electrics, ventilation, fire safety and general compliance.
Do I need structural calculations?
Usually yes if the work involves steel beams, large openings, roof changes, foundation design or removing load-bearing walls.
How long does a house extension take?
The total timeline depends on design, surveys, planning, structural calculations, building regulations, party wall matters, lead times and the size of the build.
Can you help with Party Wall agreements?
Yes. If your project affects a shared wall, boundary or nearby excavation zone, we can guide you through the party wall process and advise on the next steps.
Can you help with kitchen extensions?
Yes. Kitchen extensions are one of the most popular London projects, especially rear extensions, side returns and wraparound layouts with rooflights and garden-facing doors.
Can you help with loft conversions too?
Yes. If a loft conversion is a better way to add space, visit our loft conversions London service page.
How do I start?
Use the quote form below, call us or send your postcode, photos, drawings or ideas. We will review the project and recommend the best next step.
Will a house extension add value to my home?
A well-designed extension can improve space, layout and sale appeal, but value depends on your area, specification, build cost and final finish. We help you focus spend where it improves everyday living and long-term value.
Do you handle design and build together?
Yes. Our design and build route helps join feasibility, planning, structural coordination, building regulations and construction into one clearer process.
Can I live at home during the extension?
Often yes, depending on the scale of work, kitchen access, temporary services and safety. We explain likely disruption before work starts so you can plan properly.
What should I send for the fastest quote?
Send your postcode, photos of the property, rough measurements, drawings if you have them, and a short description of the extension you want.
Start Your House Extension with Confidence
Planning a house extension in London can feel overwhelming. We make it simple — clear advice, realistic costs, and a smooth path from design to build.
- Free consultation with no obligation
- Advice on planning and permitted development
- Guidance on structural calculations and building regulations
- Design, project management and build support
London Focus
1 Expert Team
Free Initial Review
Request Your Free Quote
Tell us about your project and we will come back to you with the best next step.
No pressure. No obligation. We reply within 1 working day.