Home Extensions in Wimbledon
At Silverain, we are proud to be Wimbledon’s trusted experts in property extensions and home improvements. Whether you’re looking to expand your living space, add value to your home, or create a more functional layout for your family life, our professional team has the experience and craftsmanship to deliver outstanding results.
With over 30 years of construction and renovation experience, we understand the unique architectural styles and planning considerations across Wimbledon and the surrounding London boroughs. From single-storey and rear house extensions to loft conversions and bespoke internal redesigns, our goal is to transform your vision into a beautifully finished reality.
Silverain Extensions
FAQs – Building an Extension
Do I need planning permission for an extension?
Not always. Many extensions fall under Permitted Development Rights if they meet size, height, and placement rules. Larger or more complex extensions require planning permission.
What are Permitted Development Rights?
These allow certain types of home extensions without a planning application, provided the design meets rules on height, footprint, materials, and distance from boundaries. Listed buildings and flats do not qualify.
How long does it take to build an extension?
- Single-storey extension: 8–16 weeks
- Two-storey extension: 12–24 weeks
- Small porch/utility additions: 4–8 weeks
This does not include design, planning, or structural approvals.
How long does planning permission take?
Local authorities usually take 8 weeks to decide a household application, though busy councils may take longer.
Do I need Building Regulations approval?
Yes if the project includes:
- Steel beams (RSJs)
- Knocking through walls
- Roof alterations
- Significant load-bearing changes
An engineer provides calculations for Building Control.
Do I need a structural engineer?
Yes if the project includes:
- Structural strength
- Fire safety
- Insulation
- Drainage
- Electrical works
An engineer provides calculations for Building Control.
Will my neighbours need to be notified?
Possibly. Under the Party Wall Act, if the work affects a shared wall or is close to a boundary, you must serve formal notices.
How much does an extension cost?
Prices vary by region and specification, but typical ranges are:
- Single-storey: £1,800–£2,700+ per m²
- Two-storey: £1,500–£2,300+ per m² per floor
- High-end finishes or complex designs cost more.
Can I live in the house during the build?
Usually yes, but expect dust, noise, and temporary disruptions. Some phases (steel installation, roof removal, or knock-through) may be more intrusive.
Will an extension add value to my home?
A well-designed extension typically adds value — often more than it costs — especially for:
- Larger kitchens
- Open-plan living spaces
- Extra bedrooms
- Home offices
Do I need an architect?
Not legally, but highly recommended. Architects ensure:
- Correct design
- Planning compliance
- Accurate drawings
- Smoother communication with builders
What insurance should I have?
You should inform your home insurer before work starts. The builder should have:
- Public liability insurance
- Employer’s liability
- Contractor’s all-risk (recommended)
What warranties or guarantees will I receive?
How disruptive will the build be?
- 12-month workmanship guarantee
- Manufacturer warranties for materials (e.g., boilers, windows)
- Optional insurance-backed guarantees
How disruptive will the build be?
Expect:
- Noise
- Dust
- Temporary loss of garden access
- Occasional water/electricity shutoffs
Good builders plan this with you in advance.
What are the stages of building an extension?
- Design & drawing
- Planning permission (if needed)
- Building Regulations approval
- Groundworks & foundations
- Brickwork & structure
- Roof installation
- Windows & doors
- First fix electrics/plumbing
- Plastering & insulation
- Second fix
- Finishing & snagging.