Steel BeamInstallers
Rear extension under construction with a steel beam over the opening into the house

Rear extension steels · Kilburn

Rear extension steels in Kilburn

Rear extension steels in Kilburn, from free survey to completion certificate.

  • Price fixed in writing once scope is agreed
  • Building control arranged
  • Temporary works and making good included

Free survey in Kilburn

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  • Free survey visit
  • Engineer's calculations arranged
  • Building control handled
  • Fixed written price once scope is agreed
  • England, Wales, mainland Scotland & NI

Planning rear extension steels in Kilburn

Our rear extension steels service in Kilburn covers everything from the first visit to the completion paperwork. Our coverage runs across London, so nearby villages are included too. Postcode districts we cover here include NW2, NW3, NW5, NW6 and NW8.

We work alongside your builder or as the steel package within the wider build. We arrange the engineer's design, coordinate building control, prop and open the rear wall at the right stage of the programme, and fit and pack the steels so the extension can be finished around them.

Key points for your project

  • The building control completion certificate for the extension covers the steelwork to the old rear wall. Keep it with the engineer's calculations and drawings, as a buyer's solicitor will expect to see the structural paperwork for the extension.
  • During the opening, props stand both inside the house and within the extension footprint. Where props bear on a newly laid slab, the propping plan checks that the slab can take those point loads, using spreaders where needed.
  • The steelwork forms part of the extension's building regulations approval, and the engineer's calculations go in with it. Planning for the extension itself is separate; many rear extensions to houses in England fall within permitted development, subject to size limits and conditions.
  • When bi-fold or sliding doors sit directly beneath the new steel, the beam has to stay stiff enough not to bind the door panels. The engineer sets a tighter deflection limit, which can mean a deeper or heavier section than strength alone would need.
  • Opening the rear wall is usually the dustiest stage of an extension project. The work face is sheeted off from the rest of the house, and the kitchen is often out of use for a few days while the opening is formed and the steel goes in.

From survey to sign-off in Kilburn

  1. Look and measure

    We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  3. Building control

    We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.

  4. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

What do rear extension steels cost in Kilburn?

As a guide, budget £3,200–£8,950 including VAT for opening into a rear extension in Kilburn, based on published UK cost guides adjusted for London prices (+28%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£3,200–£8,950Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Rear wall opening for bi-fold or sliding doors£3,200–£8,950External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Side return extension steelwork£4,500–£10,900Beams and posts along the old side wall line, propping and approvals (extension build extra)
Party wall surveyor (agreed surveyor, per neighbour)£1,150–£2,550 per neighbourSchedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only)

Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.

Building rules for Kilburn

For Kilburn, building control is provided by the local council's building control team, or by a registered building control approver if preferred. We send them the engineer's calculations with a building notice or full plans application and book the inspections. Work done without approval can cause problems at sale and is far dearer to put right later.

Terraced and semi-detached homes often need party wall notices, because cutting into a shared wall to take a beam end is notifiable under the Party Wall etc. Act 1996. Allow at least two months for the notice period unless your neighbour agrees sooner.

Building rules in England

Rear extension steels near Kilburn

Local questions answered

Do you cover Kilburn for rear extension steels?

Yes. We carry out rear extension steels in Kilburn and the NW2, NW3, NW5, NW6 and NW8 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.

Can I stay at home while the work is done in Kilburn?

Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.

Do I need a party wall agreement for extension steels?

In England and Wales, if a beam bears into a wall shared with a neighbour, or the extension foundations are dug close to theirs, notice under the Party Wall etc. Act 1996 is usually required. We can arrange the notices through a party wall surveyor. There is no equivalent legislation in Scotland or Northern Ireland.

How wide can a rear extension opening be?

There is no fixed limit, and openings across the full width of a house are common with the right steel. The engineer sizes the beam or frame for the span and the loads above. Wider spans need deeper or heavier steel and possibly columns, which affects headroom and cost.

Who designs the steels for a rear extension?

A structural engineer. Your architect's drawings show the layout, but the engineer calculates the beams, columns, connections and foundations. We arrange those calculations, or work from an engineer's design you already have, and make sure the details suit the builder's programme.

How soon can rear extension steels start in Kilburn?

Start dates depend on the engineer's calculations, the building control approval and, where needed, party wall notice periods. We give you a realistic timetable after the survey and keep you updated as each approval comes through.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.