Structural Alterations Parsons Green
Structural alterations, new openings, underpinning and floor structures in Parsons Green, designed by the engineer we appoint and inspected at every stage.
- Rated 4.9 from 31 reviews on MyBuilder
- London guide: from £1,500
- Free site survey, itemised quote
GS Renovation carries out structural alterations across Parsons Green and the wider SW6 area, from new openings in the rear closet wing to replacement joists and supported openings in the Victorian and Edwardian terraces near the green. We bring engineering, propping and building control together on one job.
In Parsons Green, a simple new opening starts from £1,500, and underpinning a single elevation typically costs £6,000 to £21,000 (indicative London ranges, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Parsons Green.
Price guide
| Work | Indicative London range |
|---|---|
| Simple new opening | from £1,500 |
| Underpinning, single elevation | £6,000 to £21,000 |
| Major structural works | from £15,000 |
Indicative London ranges (MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: RSJ & Load-Bearing Walls.
How the job runs
- Free site survey at your Parsons Green address and an itemised quote.
- The engineer we appoint designs the work, and it is registered with Hammersmith and Fulham Council building control or an approved inspector. On a shared wall you serve the party wall notice as building owner; we supply the drawings.
- Props and any trial holes first, then the opening, joists or underpinning in the engineer's sequence.
- Building control inspects each stage before it is covered, then issues the completion certificate.
Alterations to Parsons Green period homes
Every alteration on these SW6 terraces starts with understanding an old house. The bay-fronted Victorian and Edwardian properties near the green were built with lime mortar, timber floors and shallow foundations, so we ask a structural engineer to assess the existing structure before designing a new opening, a replacement steel or, where movement has appeared, underpinning to a failing corner.
Common Parsons Green work includes forming a wide opening into the side return for a kitchen extension, renewing decayed joists over a damp rear closet wing, and adding a supported opening between the kitchen and garden. In each case a steel beam is sized to the load, bears onto padstones over sound masonry, and the surrounding brickwork is made good once the props come out.
Housing in Parsons Green
On the valuation list Parsons Green counts about 8,080 homes, 67% flats and 33% houses; 68% predate 1919, 7% are interwar and 24% post-war. Structural repair to a block in Parsons Green usually falls to the freeholder under the lease, so it is agreed with them before anything is opened up, which matters here because most homes are flats.
Cellars, underpinning and the basement rules in Parsons Green
Structural work in an older Parsons Green house often reaches below ground: an old cellar under the front room, shallow footings under a rear wing, a floor someone wants lowered. Hammersmith and Fulham takes digging down seriously. Its borough-wide basement Article 4 direction came into force on 26 April 2018, and full planning permission is needed to create a new basement or extend an existing basement, including for flats, maisonettes and single dwelling houses. Digging beyond the footprint of an existing cellar is extending a basement, so it starts with a planning application, not a builder's price.
The line matters for your programme. Underpinning a cracked rear wing to stop movement is building regulations work, and the fee schedule charges other works not listed, including basements and underpinning, by cost of works. A basement scheme is a different project: a planning application for a basement requires a Construction Method Statement, and Local Plan Policy DC11 (Basements and Lightwells) only permits new basements and extensions to existing basements where they meet its listed criteria. Settle which side of that line your Parsons Green job sits on before the engineer designs anything.
Engineering and consents in SW6
Structural alterations in Parsons Green are controlled under the Building Regulations rather than planning, so Hammersmith and Fulham Council's building control inspects the propping, the beam bearings and any underpinning, then issues the certificate. We coordinate the engineer's calculations, book the site inspections at the right stages, and keep the paperwork straight from start to finish.
Where an opening, a beam or underpinning touches the party wall shared with the house next door, the Party Wall Act applies, and you serve notice on the adjoining owner first, as building owner, using the drawings we supply. On a tightly built SW6 terrace that is the norm rather than the exception, so the notices go out early and we programme the work around them, keeping your neighbours informed and the risk of disputes low.
- Load-bearing wall removal and new structural openings
- Chimney breast removal and support to the stack above
- New door and window openings in solid masonry
VOA Council Tax stock of properties, March 2025, for Parsons Green East & Eel Brook Common and Parsons Green West. Counts rounded by the VOA.
Why Choose GS Renovation in Parsons Green
For structural alterations in Parsons Green, GS Renovation gives you a single team that owns the whole process: beams and underpinning built to the design of the engineer we appoint, a programme planned around your party wall notices, building control inspections booked and passed, and safe temporary propping throughout. We keep an occupied SW6 home clean and secure as we work, and stand behind every certified result with our founder's 30+ years on the tools.
We loved working with George and Ibrahim and would highly recommend them. They have done splendid job on our new kitchen refurb which including new…
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…
FAQ
Frequently Asked Questions about Structural Alterations Parsons Green
Can you quote structural alterations for an SW6 property over the phone?
GS Renovation will not give a real quotation for structural alterations in Parsons Green over the phone, only the range, £1,500 to £21,000 or more, from a simple opening to underpinning one elevation (indicative). On 07472 424 226 we can explain what moves the cost and whether the job needs an engineer's design approved before the work starts, but the SW6 property has to be seen first. Builders who quote blind across Hammersmith and Fulham revise the figure once the floor or walls are opened.
My Parsons Green terrace has a crack in the rear closet wing. Do I need underpinning?
Not always. Cracking in an SW6 closet wing can come from old lime mortar, shallow foundations or historic movement that has long since settled. We have a structural engineer assess it first; underpinning is only specified where the foundation genuinely needs it. If it does, the engineer designs it, you serve any party wall notice it needs, we carry out the work, and building control inspects it.
What changes when forming a wide rear opening in a solid-walled Parsons Green terrace?
Victorian walls here are solid brick, so the steel must support the full wall thickness, often two beams bolted side by side or one beam with a plate under the outer skin. The masonry above is needled and propped before any cut is made. Where the opening changes the back of a building in a conservation area, Hammersmith and Fulham Council may need a planning application first.
Why do Parsons Green floors sag, and can they be fixed without lifting everything?
Joists in older SW6 houses were often notched by generations of pipework and cabling, and some were undersized from the start. The engineer may specify new timbers bolted alongside, known as sistering, which only needs boards lifted in strips. Lath and plaster ceilings below can crack as the floor is levelled, so this is done before the room beneath is decorated.
Is structural work in a listed Parsons Green building treated differently?
Yes. For a listed building, knocking through or altering structure inside also requires listed building consent, on top of building regulations approval, and nothing starts until that consent is granted. The application normally has to show which historic fabric is affected, so the engineer's scheme is drawn up first. An unlisted SW6 house needs building control for internal structural work, but not planning.
Should the engineer survey before the builder programmes Parsons Green structural work?
Ideally, yes. The engineer's survey and calculations fix the steel sizes, bearings, padstones and temporary works, and without them no firm programme is possible. Opening up a patch of lath ceiling is sometimes needed to confirm which way the joists run. The same calculations then go into the building control application, so this step sets the pace for everything after it.
How far under the garden can a Parsons Green basement extension go?
The Local Plan basements policy requires that a basement does not extend into or underneath the garden further than 50% of the depth of the garden. It also requires a minimum of one metre of soil above any part of a basement beneath a garden, and no more than one storey, with exceptions possible on large sites. Measure the garden before sketching the room, because on a short plot the half-depth limit decides the size.
Is a flood risk assessment needed for structural work below ground in Parsons Green?
Only where the work needs a planning application. Two thirds of the borough is within a flood risk zone, and Hammersmith and Fulham asks for a flood risk assessment with a planning application for a property in one. That catches a basement scheme, since full planning permission is needed to create or extend one, but underpinning that needs only building regulations approval has no planning application to attach it to. For a basement, check the zone first, because the assessment shapes the waterproofing, drainage and any pumped outlet.
Can underpinning a Parsons Green rear wing go through on a Building Notice?
The council recommends a Building Notice only for very small works and says it should be avoided for complex building work, and underpinning is complex. The council's guidance for extensions and basement conversions under a Building Notice still requires a set of structural calculations for all structural work, and underpinning needs the engineer's design whichever route is used. A Full Plans approval means the bay sequence and depths are checked before the first bay is dug.
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