Porch extensions across Carshalton
Our design and build teams take on porch extensions in Carshalton, from the first measured survey through planning and building control to the finished room.
- Guide price in CarshaltonFrom £5,200 inc VAT
- PlanningUsually permitted development under 3 m²
- Build time2–4 weeks on site
- Postcode districtsSM1, SM2, SM3, SM4, SM5
What is included
- Planning check against the porch limits
- Tiled, slate or flat roof
- Brick, render or oak frame walls
- Front door, glazing and electrics
- Foundations and drainage for rainwater
Do I need planning permission in Carshalton?
In England a porch is usually permitted development if its ground floor area is no more than 3 m² measured externally, no part is over 3 m high, and no part is within 2 m of a boundary next to a road.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Carshalton
Postcode districts we cover around Carshalton include SM1, SM2, SM3, SM4, SM5, SM6. We also work in nearby Wallington (1 mile), Sutton (2 miles), Mitcham (2 miles), Morden (2 miles).
Banstead, in Surrey, is roughly 4 miles from Carshalton and also on our list. Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
What should I budget for a porch extension in Carshalton?
Prices below are for Carshalton, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Small brick or glazed porch, up to 3 m² | £5,200 – £8,450 |
| Standard | Brick porch with tiled roof and composite door | £7,800 – £12,350 |
| Premium | Larger porch with WC or oak frame and premium glazing | £11,700 – £19,500 |
For a figure based on your own dimensions, use our guide-price tool.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Carshalton home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a porch extension in Carshalton
Do I need building regulations approval in Carshalton?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a porch extension take to build in Carshalton?
On site, typically 2 to 4 weeks once approvals are in place. Before that, allow 2–8 weeks design and approvals.
Do you cover all of Carshalton?
Yes. We cover Carshalton and the surrounding parts of Greater London. Site visits are free and there is no obligation.
How much does a porch cost?
Our guide range is about £5,200 to £19,500 including VAT, depending on size, materials and whether it includes a WC.
Do I need planning permission for a porch?
In England a porch is usually permitted development if its ground floor area is no more than 3 m² (measured externally), no part is higher than 3 m, and no part is within 2 m of a boundary next to a highway. Other nations have similar but separate rules.
Book a free site visit in Carshalton
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.