Structural Alterations Hammersmith
Structural alterations, new openings, underpinning and floor structures in Hammersmith, 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
From new door openings to replacement joists and underpinning, GS Renovation carries out structural alterations throughout Hammersmith's W6 streets. Our founder's 30+ years on the tools means we understand how these homes are built, and how to change them without weakening the fabric that has stood for a century.
In Hammersmith, 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 Hammersmith.
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 Hammersmith 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.
Structural alterations for Hammersmith's period homes
Older W6 terraces throw up a range of structural jobs. You might want a wide supported opening into the rear closet wing, a new opening formed in a solid brick wall, or original timber joists replaced where past leaks near the roof valleys have caused rot. Each starts with an engineer specifying the beam, lintel or joist size and the bearings, so the alteration is designed for your specific house rather than assumed.
Underpinning comes up too, usually where seasonal ground movement or historic settlement has left cracking in a Hammersmith terrace. We work in short controlled bays beneath the existing footings, pouring mass concrete to the depth the engineer designs so the wall is supported without undermining it. Whatever the alteration, the principle is the same: understand the load path first, then build the new support before removing the old.
Housing in Hammersmith
By the valuation list's count, Hammersmith holds about 15,040 homes, 23% houses and 77% flats; by age, 56% were built before 1919, 9% between the wars and 34% since 1945. Most homes here are flats, and structural repair to a block in Hammersmith usually falls to the freeholder under the lease, so it is agreed with them before anything is opened up.
Structural repairs to the front of a Hammersmith house
A bulging front wall, a dropped bay or a failed lintel over the front door is a structural repair, but in Hammersmith it can also be a change to the street, and that brings the conservation side in. Hammersmith and Fulham has 44 conservation areas covering about half of the borough. Article 4 Directions restricting some permitted development rights have also been made on some properties in Hammersmith Grove. A like-for-like repair keeps the elevation as it was, while rebuilding a bay in a different brick, or widening an opening, is a change that may need permission. So the repair is specified to match before anything is taken down.
The boundaries are worth checking even if you checked when you bought. On 13 November 2018 the boundaries of 11 of the borough's conservation areas were extended or amended, and that same day the King Street (East) Conservation Area took the name Hammersmith Town Hall Conservation Area. A survey or search from before then can name the wrong area or miss the designation entirely. We look up the current map for the address before specifying any external structural repair, so the brick, the pointing and the lintel detail are chosen for the right designation.
Getting alterations signed off in W6
New openings and beams that pick up on the party wall bring the Party Wall Act into play, exactly as with any shared wall in these terraces. You serve the required notice on the neighbour as building owner, including for underpinning near the boundary, and we give you the drawings and programme each notice needs. Getting the party wall position right early avoids disputes and keeps a Hammersmith project moving on schedule.
Structural alterations are controlled under the Building Regulations, so Hammersmith and Fulham Council's building control inspects the works rather than the planning department. Internal changes do not need planning permission; external changes may, and a conservation area controls them more tightly, while a listed building needs listed building consent inside too. We keep the two separate, arrange the right inspections at the right stages and hand over the completion certificate at the end.
- Load paths carried down to foundations on new piers and pads
- Chimney breast removal and support to the stack above
- Building control applications, inspections and the completion certificate
VOA Council Tax stock of properties, March 2025, for Hammersmith Broadway, Brook Green, Ravenscourt Park North and Ravenscourt Park South. Counts rounded by the VOA.
Trusted Structural Alterations in Hammersmith
For structural alterations in Hammersmith you want one team that owns the whole process, and that is what GS Renovation provides. We coordinate the engineer, carry out underpinning or new openings safely, and manage building control to sign-off. Our founder's 30+ years of work stand behind every job, done tidily in your home.
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 Hammersmith
Are there hidden costs with structural alterations in Hammersmith?
Every extra cost on structural alterations in Hammersmith needs your written agreement, and the foreseeable ones are already priced within £1,500 to £21,000 or more, from a simple opening to underpinning one elevation (indicative). Work in late Victorian or Edwardian housing around W6 occasionally reveals something behind plaster; when it does, GS Renovation stops, costs it and waits for your decision. The sequence of work stays fixed: the engineer's design is issued before the building control application.
Do structural alterations in Hammersmith need planning permission?
Internal structural alterations, such as new openings, replacement joists or underpinning, are controlled under the Building Regulations and signed off by Hammersmith and Fulham building control, not planning. Planning is a question only for external changes, which a conservation area controls more tightly, but a listed building needs listed building consent for internal work too. We tell you clearly which applies to your W6 property.
What causes the sloping floors in my Hammersmith period flat?
Usually old movement rather than something current. In a house built before 1919, as 56% of Hammersmith's stock was, floors dip where walls below were removed without adequate support, where joists were notched for pipes, or where the building settled long ago. The engineer's job is to decide whether movement has stopped. If it has, levelling may be cosmetic; if not, the support is corrected first.
What if a previous owner removed a wall in my Hammersmith house without steel?
It is more common than people expect in older houses, and it usually shows as a sagging ceiling, a cracked wall above or a door that no longer closes. Opening up reveals what was done. The engineer then designs retrospective support, often a beam inserted under the load, and Hammersmith and Fulham building control inspects it as new structural work.
Does underpinning a Hammersmith house divided into flats affect everyone?
Yes, because the foundations are shared by the whole building. Underpinning needs Building Regulations approval, the freeholder's consent and usually the agreement of other leaseholders whose homes sit above. If digging goes within 3 metres of the neighbouring house to below its footings, a month's party wall notice applies. The engineer's monitoring comes before any of that, to confirm underpinning is truly needed.
Why is the front wall of my Hammersmith Victorian house bulging?
Often because it has lost its restraint at floor level. Solid Victorian walls rely on being tied to floors and cross walls, and where joists run parallel to the front wall, nothing holds it back. Over time it can lean outward. The usual repair is steel restraint straps fixed across several joists and into the wall, designed by an engineer and inspected by building control.
Does lowering a cellar floor in a Hammersmith house need planning permission?
Plan on it. Full planning permission is needed to create a new basement or extend an existing one, and that includes flats, maisonettes and single dwelling houses. The borough-wide Article 4 direction removing permitted development rights for basement development was made on 25 April 2017. A basement application also needs a Construction Method Statement. Lowering the floor for headroom enlarges the cellar downwards and means underpinning, so the engineer's design and the planning case are prepared together.
How is building control charged for underpinning a Hammersmith house?
By the cost of the work rather than a fixed fee. The fee schedule treats works it does not list, including basements and underpinning, as charged by cost of works. That means the contract value has to be estimated before the application is priced, so the structural engineer's scheme needs to be clear enough to price first.
Can a tree blamed for subsidence be removed quickly in a Hammersmith conservation area?
Not without notice. The council has to be given six weeks' notice of work to a conservation area tree with a trunk 75mm or more in diameter. Where an engineer links cracking to a nearby tree, that six weeks is part of the repair programme, because whether the tree stays decides what the underpinning has to do. The engineer's monitoring usually continues through the notice period anyway.
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