House Extensions Parsons Green
Single storey rear and double storey extensions in Parsons Green, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
GS Renovation plans and builds extensions across Parsons Green, working with the bay-fronted Victorian and Edwardian terraces near the green that have rear closet wings and side returns waiting to be used. We take your extension from foundations to full fit-out as one project.
In Parsons Green, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Parsons Green: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Parsons Green
Parsons Green range: choose above
Side-return and rear extensions in Parsons Green
The most popular extension on a Parsons Green terrace fills in the side return, that narrow strip alongside the rear closet wing, and often adds a single-storey rear extension to create a wide kitchen-diner opening onto the garden. We handle the groundworks and foundations, allowing for the shallow Victorian footings and any nearby trees on these SW6 plots, then form the new opening with a steel beam sized by the engineer.
Double-storey and wrap-around extensions are also common where owners want an extra bedroom or en-suite above. We manage the roof works, whether a flat roof with rooflights or a pitched tie-in to the existing slope, and match the London stock brick and detailing so the addition sits comfortably against the original terrace and its neighbours.
Housing in Parsons Green
Around 8,080 homes make up Parsons Green on the valuation list; 67% are flats and 33% houses, and 68% date from before 1919, 7% from between the wars and 24% from after 1945. Where most homes are flats, a flat in Parsons Green has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.
Floor area, trees and flood zones on a Parsons Green extension
Developments that add 100m2 or more of new floorspace or create a new dwelling are liable for CIL in Hammersmith and Fulham. A side return on a Parsons Green terrace is nowhere near that, but the figure counts new floorspace on every level, so a double storey wrap-around on a larger house deserves a measured check. The gross internal area is taken off the drawings before the application goes in. If a scheme is close to the line, raise it at design stage: an owner extending their own home may be able to claim an exemption, but the claim has to be made before work starts.
Two other checks belong at the start. Works to a tree in a conservation area with a trunk diameter of 75mm or more need six weeks' notice to the council. If your Parsons Green house is in one and a tree near the new footings has to be cut back, that notice goes in before the programme starts, not when the digger arrives. And two thirds of the borough is within a flood risk zone, with a flood risk assessment requested alongside a planning application for a property in one. Checking the zone for your street at design stage keeps that report from holding up validation.
Planning and party walls near the green
Whether your extension is permitted development or needs a full planning application depends on the property. A single-storey rear extension on a Parsons Green terrace can fall under permitted development, but a side or side-return extension in the Parsons Green Conservation Area needs planning permission from Hammersmith and Fulham Council, and a house already extended may have used its allowance. The council also lists property-specific Article 4 directions named Parsons Green (1), (2) and (3), so we check whether your address is covered before relying on permitted development, and advise on the right route before any work begins.
Extensions always need building regulations approval for the structure, foundations, insulation and drainage, which is separate from planning. Because you are building right up to the boundary and often against a shared wall, party wall notices to the neighbours either side are usually required, and you serve them as building owner, using the drawings we supply. We work with your designer on the council submission, book the building control inspections and plan the programme around the notices so the whole process runs in order.
Kitchen extensions in Parsons Green
67% of homes in Parsons Green are flats, and a flat has no householder permitted development, so a ground-floor flat's kitchen extension needs planning permission from Hammersmith and Fulham Council and the freeholder's consent. Most kitchen extensions here are on the 33% of homes that are houses. The fit-out is priced on its own page, kitchen renovation in Parsons Green; the build figures are in the table above.
Double storey extensions in Parsons Green
Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Parsons Green often needs planning permission from Hammersmith and Fulham Council. It is a job for the 33% of homes that are houses; a flat cannot add a storey this way. The council's list of property-specific Article 4 Directions includes Parsons Green (1), Parsons Green (2) and Parsons Green (3) (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- Bi-fold, sliding and French door openings to the garden
- Trial holes to set foundation depth near drains and trees
- Planning applications and permitted development assessments
VOA Council Tax stock of properties, March 2025, for Parsons Green East & Eel Brook Common and Parsons Green West. Counts rounded by the VOA.
Trusted House Extensions in Parsons Green
Homeowners in Parsons Green choose GS Renovation because one team runs the whole extension, from foundations, steel and roof to the finished work and final decoration. We know how the terraces near the green behave, advise honestly on permitted development versus planning, and deliver a build that adds real space and value in SW6, backed by our founder's 30+ years on the tools.
- Free follow-up visit after completion if anything needs attention
- Permitted development checked before you pay for a planning application
- Building control inspected at foundation, damp course and steel stages
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
It's the second time I have hired George and he has been absolutely professional and the work he did resembles perfectly what I had in mind. Being an…
FAQ
Frequently Asked Questions about House Extensions Parsons Green
Why do house extensions quotes in Parsons Green vary so much?
Variation in house extensions quotes across Parsons Green almost always comes from what has been left out. GS Renovation prices structure, trades, approvals and reinstatement after an SW6 survey, so the total can look higher than a quote covering half of it. The honest range is £2,000 to £2,800 per m² for a rear extension (indicative), and the drainage run under the footprint decides the foundations, which a quote without a survey cannot know.
What does a side return infill add to a Parsons Green house?
Width where the plan is at its most awkward. The terraces around Parsons Green typically have a narrow rear wing with a passage beside it, and infilling that strip turns a corridor kitchen into a room the full width of the plot. The rear and side walls of the wing are opened, the loads carried on steel designed for the new spans, and rooflights bring light into what becomes a deep floor plate.
How are garden levels handled on a Parsons Green extension?
By setting the finished floor level before the foundations are poured. Gardens behind Parsons Green terraces are often higher or lower than the internal floor, and the relationship between the two governs the threshold detail, the damp proof course and where surface water goes. Getting it wrong produces a step nobody wanted or a threshold that lets water in. Levels are surveyed at the outset and drainage falls designed to suit.
Does building an extension in Parsons Green need access to the neighbour's land?
Frequently, to build or finish a wall on the boundary. Where a Parsons Green extension sits against a shared boundary, scaffolding or finishing the outer face may require entry next door. Access of that kind is agreed with the neighbour, or arranged under the Party Wall Act where the work falls within it, rather than assumed, and the timing is agreed with the neighbour in advance. Work is planned so any period of access is short and the ground is reinstated.
What supports a large rooflight over a Parsons Green side return?
Steel designed for the opening and the glass it carries. A long rooflight over a Parsons Green infill removes most of the roof structure over that span, so the remaining loads are taken on beams sized by the engineer, with the deflection limited so the glazing is not stressed. The upstand, the weathering detail and the thermal break matter as much as the steel, because that is where a rooflight leaks.
How is a Parsons Green house kept secure while the back is open?
Boarded and locked at the end of each working day rather than sheeted alone. Where the rear wall of your Parsons Green property is removed to join an extension, the opening is closed with a temporary door or boarding, and the alarm arrangement is discussed with the owner. The exposed period is kept short by preparing everything before the wall is taken out.
Does an extension under 40m2 in Parsons Green have its own building control fee band?
Yes. The fee schedule lists an extension of less than 40m2 as its own item, and the total is the same whether you use Full Plans or a Building Notice. So the choice is about risk, not fee. Under a Building Notice for extensions, a set of structural calculations must be submitted for all structural work anyway. Full Plans gives you approved drawings before the foundations are dug.
Is pre-application advice worth it before a Parsons Green extension application?
Where the house is in a conservation area or covered by a property-specific Article 4 direction, often yes. The council's list of property-specific Article 4 Directions includes Parsons Green (1), Parsons Green (2) and Parsons Green (3). For 2026/27 householders can choose written pre-application advice or a meeting with a planning officer. A meeting suits a scheme with a design question, such as the depth of a rear addition. Written advice suits a simple one.
When did the CIL charging schedule start applying to Parsons Green extensions?
The Hammersmith and Fulham CIL Charging Schedule was approved on 20 May 2015 and became effective on 1 September 2015. It applies to developments that add 100m2 or more of new floorspace or create a new dwelling. A single-storey rear extension usually sits below that, but adding a self-contained flat creates a new dwelling, which meets the liability test whatever its size, so mention any plan to let part of the house early.
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