Rear Double-Storey Extensions
Extend from the back of the house to create a larger kitchen, dining or living space below and extra bedroom or bathroom space above.
Popular for family homesLondon design & build specialists
Double Storey Extensions London
Create extra space on two floors with a bespoke double-storey extension designed around your London home, planning route, budget and long-term family needs.
Londonlocal extension specialists
2 Floorsextra living space
Freeinitial consultation
Clearfixed pricing approach
Expand your home without moving
Designed for London homes that need serious extra space
A double-storey extension is one of the most effective ways to add meaningful space to your home because it improves both the ground floor and first floor at the same time.
If you love your London property but need more room, a two-storey extension can create a larger kitchen or living space downstairs while adding a bedroom, bathroom, office or master suite upstairs.
Our service is built for London homeowners who want a clear route through feasibility, design, planning permission, building regulations and construction.
- Ideal for growing families who need more bedrooms and better living space
- Designed to blend with the original house, roofline and materials
- Guidance on planning permission, party wall matters and structural design
- Managed construction process with clear communication from start to finish
What is a double-storey extension?
A double-storey extension is a two-floor addition to your existing home, usually built to the rear or side of the property. It gives you extra floor area upstairs and downstairs, making it suitable for homeowners who need more than a small ground-floor improvement.
Side Double-Storey Extensions
Use available side space on semi-detached or detached homes to create a wider layout across two levels.
Great for wider plotsTwo-Storey Kitchen Extensions
Open up the ground floor with a modern kitchen-living layout while improving the first-floor bedroom arrangement.
Space upstairs and downstairsBedroom & Bathroom Extensions
Add a master suite, family bathroom, nursery, office or guest room above a new ground-floor living area.
Designed around your lifestyleSimple managed process
Our double-storey extension process
Two-storey extensions need careful planning, structural design and coordination. We keep the process clear, practical and professionally managed from the first conversation.
Consultation & feasibility
We discuss your goals, review your property and advise whether a double-storey extension is suitable for your London home.
Design, planning & structural route
We help with concept design, planning permission guidance, building regulations and structural requirements.
Construction & project management
Our team manages the build, schedule, communication, inspections and quality control through each stage.
Completion & handover
We complete finishes, checks and handover so the new upstairs and downstairs spaces are ready to use.
Planning permission and regulations for double-storey extensions
Double-storey extensions in London usually need careful planning review. The PDF guidance notes that many London two-storey extensions require planning permission because of stricter size, height, boundary and overlooking rules.
- Two-storey rear extensions under permitted development are heavily limited and often restricted to around 3m projection.
- The extension must usually remain a suitable distance from boundaries and avoid overlooking or loss of light issues.
- Materials, roof design and appearance should normally match the existing home.
- Party wall matters may apply for terraced and semi-detached properties.
- Building regulations approval is needed for structure, insulation, fire safety, drainage and electrics.
Benefits of a two-storey extension
A well-designed double-storey extension can transform how your home works now and improve its long-term value.
More living space
Create a larger kitchen, dining room, family area or utility space on the ground floor.
Extra bedroom space
Add bedrooms, bathrooms, an office or a master suite upstairs without moving home.
Better value per square metre
Because the foundations and roof serve two levels, double-storey extensions can be more efficient than building two separate projects.
Improved property value
Extra bedrooms and better living space can make your London home more attractive to future buyers.
Stay in the area you love
A larger home means you can avoid the cost and disruption of moving away from your current location.
Bespoke layout
Your extension can be designed around your family, storage, natural light, entertaining and day-to-day routines.
Double-storey extension costs in London
Costs depend on size, structural complexity, access, finish level, glazing, bathrooms, kitchen requirements and planning conditions. The PDF guidance highlights London double-storey extension costs often around £1,800–£2,500 per m², with many projects ranging from about £70,000 to £150,000+ depending on specification.
Modest two-storey extension
Suitable for straightforward designs, standard finishes and simpler structural requirements.
Approx. £70k–£100kMid-range London project
Popular for family homes needing quality finishes, planning support and a balanced design.
Approx. £100k–£150kHigh specification build
For larger layouts, complex steelwork, premium glazing, bathrooms, bespoke kitchens and luxury finishes.
£150k+Detailed quote
After reviewing your home and requirements, we provide a clearer quotation for the full scope.
Free consultationWhy choose us for your London double-storey extension?
You need a team that understands London homes, planning constraints, structural requirements and the importance of a clean, well-managed build.
London-focused expertise
We design around common London property types, including terraces, semi-detached homes and compact plots.
Design & build support
Keep your project simpler with one coordinated route from idea and drawings through to construction.
Planning guidance
We help you understand whether planning permission is needed and what local councils may expect.
Structural awareness
Two-storey extensions require careful foundations, steelwork and building regulations planning.
Project management
Communication, scheduling and site coordination are managed so the build runs as smoothly as possible.
Transparent pricing
Clear quotations and practical advice help you understand the likely investment before committing.
Frequently asked questions
Helpful answers before you start planning your London double-storey extension.
Do I need planning permission for a double-storey extension?
Most double-storey extensions in London require planning permission. Some modest rear extensions may fall within permitted development limits, but two-storey projects are much more restricted than single-storey extensions. We check the correct route before you proceed.
How much does a double-storey extension cost in London?
Costs vary by size, specification, structure and finish. A common London guide is around £1,800–£2,500 per m², with many projects ranging from about £70,000 to £150,000+ depending on complexity.
How long does a double-storey extension take?
Construction commonly takes around 3–6 months depending on the build. The full project including design, planning and building control can take longer, so we provide a realistic programme before work begins.
Will a double-storey extension add value?
Yes, a well-designed double-storey extension can improve both living space and property value, especially where it adds bedrooms, bathrooms and a better ground-floor layout.
Do I need an architect or structural engineer?
A two-storey extension normally needs professional design and structural input. We can help coordinate drawings, structural calculations and building regulations requirements.
Can I live in my home during construction?
In many cases yes, but there will be disruption during demolition, foundations and structural work. We plan the build to keep communication clear and disruption as controlled as possible.
Start your double-storey extension with confidence
Tell us what you want to create and we will advise on the best next step, from feasibility and planning through to construction.
- Free consultation with no obligation
- Advice on planning permission and party wall matters
- Guidance on structural calculations and building regulations
- Design, project management and build support
London Focus
2 Floor Extension
Free Initial Review
Request Your Free Quote
Tell us about your project and we will come back to you with the best next step.
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Ready to add space on two floors?
Speak with our team about your double-storey extension and get clear guidance on design, planning, cost and build options.