Structural alterations, new openings and steel support in New Malden. Trusted, professional, 30+ years' hands-on experience.
GS Renovation carries out structural alterations across New Malden and neighbouring Surbiton, working on the 1930s semi-detached and interwar suburban houses that define KT3. In over 30 years we have formed new openings, replaced tired joists, underpinned settled foundations and installed supported openings, always to a structural engineer's design and Kingston Council building control approval.

Interwar houses in New Malden throw up a familiar set of structural jobs. Original softwood floor joists can sag or suffer decay near solid walls, wide openings are wanted between rooms on these deeper plots, and the ground movement common to the London clay under this part of Kingston upon Thames can leave a corner needing underpinning. Each of these is a job we take on regularly.
Every alteration begins with a structural engineer. Whether we are forming a new opening with a steel beam on padstones, sistering or replacing joists, or underpinning a foundation in careful hit-and-miss bays, the design is calculated first. We prop temporarily, work in a controlled sequence and never remove support until the permanent structure is fully in place and load-tested.
Structural alterations inside a New Malden house are governed by the Building Regulations rather than planning. You will not normally need planning permission to replace joists, underpin or form an internal opening; Kingston Council building control inspects and certifies the work. Planning only comes into play for external changes, and only conservation-area or listed properties need that extra layer of consent, which is rare among these standard interwar semis.
The semi-detached layout means one side of the house shares a party wall with the neighbour. Underpinning near that wall, or cutting an opening that bears into it, is notifiable under the Party Wall Act. We coordinate the work around the party wall award and the adjoining-owner coordination alongside the engineering, so consents, controls and the physical work are all managed by the same team from start to finish.
GS Renovation is the sensible choice for structural alterations in New Malden because you deal with one team throughout. We commission the engineer, serve any party wall notices on the adjoining semi, arrange Kingston Council building control inspections and carry out underpinning, joist and opening work cleanly. Three decades in KT3 means no surprises on these interwar houses.
George was a great find. The job required re-plastering the walls before fitting acrylic panels. He also re-plumbed the shower waste under the solid…
I am very happy to recommend George after he completed the work on my 2 bathrooms. He worked very hard to make sure everything was completed and even…
My husband and I are extremely pleased with the work. The standard of the work is outstanding and Saiid has a great eye for detail and will not leave…
FAQ
We would rather not, because a phone figure is a figure that changes. What structural alterations cost at a KT3 address depends on structure and condition we can only see on site, particularly in 1930s and interwar housing. GS Renovation will happily talk through the likely scope on 07472 424 226, then survey the New Malden property free of charge. The written quotation follows that visit. Nothing is owed for the KT3 visit, in Kingston upon Thames or anywhere beyond it. As a rough guide, structural alterations in London ranges from roughly £1,500 for a simple opening to £15,000 or more where underpinning or major works are involved (indicative London ranges, MyBuilder and Checkatrade, 2026). Your figure depends on the size, specification and condition of the property, which is why we survey before quoting.
Longer than the build alone, because approvals come first. A structural alterations project at a KT3 address needs the engineer's design where the structure requires it, then a Kingston Council application, before the New Malden programme begins. GS Renovation runs those in parallel wherever possible. The survey costs nothing and is the quickest way to get real dates in Kingston upon Thames. Ring 07472 424 226 and we will explain which Kingston Council route suits your KT3 property best.
No, and no contractor should. GS Renovation appoints and coordinates a structural engineer where structural alterations at your KT3 property requires a design, then builds to their specification and has it inspected by Kingston Council. The calculations are the engineer's professional responsibility. Any builder in New Malden claiming to produce them in-house is worth questioning closely. Ring 07472 424 226 and we will explain how a Kingston upon Thames appointment works. The calculations belong to you and to the Kingston upon Thames record.
Only work changing the outside. Internal beams, new openings and floor structures in a New Malden house engage building regulations rather than planning. A new external opening, or anything on a listed or conservation-area property, needs an application to Kingston Council.
Damp, decayed timber and load paths that are not where anyone expected. 1930s semi-detached and interwar suburban houses on generous plots hide all three, which is why structural alterations at a KT3 address starts with careful opening up rather than demolition. GS Renovation tells a New Malden homeowner immediately and prices the fix in writing. Nothing proceeds on a Kingston upon Thames site until you have agreed it. Email info@gsrenovationltd.co.uk and we will explain how structural alterations variations are agreed at a KT3 property.
No. Internal structural alterations such as underpinning, replacing joists or forming supported openings fall under the Building Regulations, so Kingston Council building control approves and certifies them rather than planning. Planning only applies to external work on conservation-area or listed buildings, which is uncommon among New Malden's standard interwar semis. Where a shared party wall is affected, you serve party wall notice.
Every part, houses and flats alike. GS Renovation works across New Malden and the KT3 area and much of South West London, so structural alterations at your KT3 address is straightforward to service. The constraint is capacity rather than geography. Call 07472 424 226 early if the Kingston upon Thames project has a deadline attached. We will tell a New Malden homeowner honestly when the next slot is. Small jobs are as welcome as large ones here, and the written quotation follows within days.
Every Service, One Team
The same trusted team, 30+ years' hands-on experience and free, no-obligation quotes apply to every GS Renovation service in New Malden. Explore what else we do locally:
Same Service, Nearby Areas
We carry out structural alterations across New Malden and the surrounding areas. Explore a nearby location:
Free, no-obligation quote for structural alterations in New Malden. Rated 4.9 from 31 reviews on MyBuilder, fully insured, and building control handled for you.