GS Renovation installs steel beams and RSJs across Marylebone, from the red-brick mansion blocks off the main streets to the purpose-built period flats of W1. With more than 30 years of experience working inside Westminster's leasehold buildings, we open up load-bearing walls safely, with a structural engineer's calculations and full building control sign-off.
Steel beams inside Marylebone mansion flats
Removing an internal wall in a Marylebone mansion flat is rarely a simple knock-through. These purpose-built period blocks carry loads down through a stack of flats, so a wall on your floor may be supporting the flats above. We commission a structural engineer to calculate the beam, specify the padstones it bears onto and confirm the temporary propping needed while the wall comes down in controlled stages.
Because almost every flat in W1 is leasehold, the steelwork also has to satisfy the freeholder and their managing agent before a single prop goes up. We prepare the drawings and method statement that a licence to alter usually demands, coordinate access and noisy-works hours with the building management, and keep the block's other residents informed so the job runs without friction.
Party structures and building control in W1
In a Marylebone block the wall or floor you are altering is frequently a party structure shared with a neighbouring flat, which brings the Party Wall Act into play. you serve the correct notices on adjoining leaseholders, allow for their response period and work to the agreed award, so the steel goes in without a dispute stalling the project or souring relations in the block.
Every beam we fit is signed off under building regulations, not planning permission, since this is internal structural work. Westminster City Council's building control, or an approved inspector, checks the engineer's design, inspects the bearings and propping and issues the completion certificate. That certificate is the document your freeholder, and any future buyer's solicitor, will expect to see on file.
- Ceiling and floor levels resolved where the beam sits below joists
- Level, plumb and deflection checks before props are struck
- Making good, plastering and finishing around the new steel
- Steel columns, base plates and bolted connections
- Structural engineer's calculations arranged and followed
The GS Renovation Difference in Marylebone
Marylebone owners choose GS Renovation because we understand the leasehold and party structure realities of W1, not just the steelwork. We handle the engineer's design, the licence to alter paperwork and building control as one coordinated job, and our 30+ years across Westminster mean we prop, cut and beam in occupied blocks cleanly and safely.
- Waste cleared as we go, not left piled in the garden
- Fully insured, with cover in place on every site
- Steel sized to the engineer's design, never guessed on site
- Founder-led team with 30+ years of hands-on experience
- Beams boxed and fire protected to the approved detail
- Making good and plastering priced in, not treated as an extra