From new openings to replacement joists and supported structures, GS Renovation carries out structural alterations across Marylebone's mansion blocks and period flats in W1. Three decades of Westminster experience mean we design the right fix, prop and pour it safely, and see it through building control while your neighbours in the block carry on undisturbed.
Structural alterations in Marylebone period flats
Marylebone's purpose-built flats were laid out for a different era of living, so alterations here range from forming a new opening between rooms to replacing tired timber joists and creating supported openings where a section of wall must go. In the older mansion blocks, floor structures can sag or bounce after a century of use, and replacement joists or strengthening are common alongside any layout change our clients ask for.
Every one of these jobs starts with a structural engineer sizing the beam or joists for the actual loads involved. Steel bears onto padstones, temporary props take the weight while we work, and demolition is staged so nothing is ever left unsupported. Underpinning is rarely needed in an upper-floor W1 flat, but where a ground-floor or lower-ground home shows movement, we can design and carry that out too, all under building control.
Consents and sign-off in Marylebone
Internal structural alterations are governed by the Building Regulations, not planning permission, and Westminster City Council's building control inspects and certifies the work. Planning only enters the picture if your flat is in a conservation area or listed building and you alter the exterior, which is common in parts of Marylebone. Inside your own flat, the real gatekeeper is usually the freeholder, whose licence to alter must be granted before a beam is installed.
We manage that whole chain for you. The engineer's calculations go to the managing agent for the licence to alter, the same drawings satisfy building control, and we plan the works around the block's rules on working hours and access. Because so many Marylebone flats sit above or beside occupied homes near Oxford Street and the West End, we prop carefully and keep the site tidy so the building keeps running normally.
- Building control applications and certification
- Steel beam and RSJ installation
- Load-bearing wall removal and new openings
- Underpinning and foundation strengthening
- Floor structure, joists and beam replacement
Trusted Structural Alterations in Marylebone
For structural alterations in Marylebone, GS Renovation gives you a single accountable team from survey to sign-off. Our engineer sizes every beam and joist, we secure the freeholder's licence to alter and building-control certification, and we work cleanly around your block's rules. Thirty years-plus in W1 mean the props go in right and nothing is left to chance.
- Free, no-obligation quotations
- Over 30 years of experience
- Dedicated project management
- Fully insured and guaranteed work
- Building control and planning support
- Clean, tidy and reliable tradespeople