Open-Plan Conversions Brentwood

An open plan conversion joins rooms that were built separate, which means a wall comes out and a beam goes in. We survey, appoint a structural engineer for the calculations, build to what they issue, and take the job through to floors, ceilings, decoration and sign off. We never write the calculations ourselves. This page covers what the work involves on a Brentwood property.

For Brentwood, on London-derived ranges a knock-through finished as one room typically costs £3,000 to £8,000 or more, including the steel beam; Essex work generally runs below that. GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Brentwood: the structural engineer we appoint designs the steel, we install it, and building control signs it off.

How the job runs

1. Free site survey at your Brentwood address, covering the walls, services and floor levels, and an itemised quote.
2. The engineer we appoint sizes the beam, and the work is registered with Brentwood Borough Council building control or an approved inspector. On a shared wall you serve the party wall notice as building owner; we supply the drawings.
3. Props in, opening cut, beam on padstones; then floors, heating and electrics are joined up.
4. Building control inspects the steel before it is covered. We finish the room, and the completion certificate follows.

Three bedroom homes are 35 per cent of the borough's stock

The Brentwood Local Plan gives the most common home size in the borough as three bedrooms at 35 per cent of the stock, followed by two bedrooms at 25 per cent and four bedrooms at 23 per cent. It also records detached and semi detached houses as almost 63 per cent of the borough's stock, against a national average of 53 per cent, while the VOA count for Brentwood town alone is 40 per cent.

Those figures describe a stock built with separate rooms rather than one space. Joining a kitchen to a dining room, or a dining room to a rear reception, means finding out first whether the wall between them is doing structural work. The structural engineer sizes the beam. Our job is the survey, the propping, the steel and everything that follows it.

Housing in Brentwood

Around 25,620 homes make up Brentwood on the valuation list; 32% are flats and 68% houses, and 11% date from before 1919, 11% from between the wars and 78% from after 1945. A semi in Brentwood usually opens up with one beam, one end on the shared wall, and 21% of homes here are semi-detached.

Shenfield has no conservation area, so external changes run on the ordinary rules

None of Brentwood borough's 13 designated conservation areas covers Shenfield. Where an open plan scheme brings in wider rear glazing or a new opening in the back wall, that designation is the difference between a planning question and a permitted development one.

Elsewhere in the borough the position changes by address, so confirm your own with the council before a rear elevation is redrawn. We flag it at survey and tell you what to check, but the designation is the council's to confirm.

In the town centre the wall you want out may be part of a frame

Behind the 19th century fronts of nos. 108 to 114 Brentwood High Street there are the remains of timber frames, and the council's appraisal states it is probable that there are other survivals in the High Street concealed by later brickwork.

An open plan scheme in a building like that is a different exercise from one in a 1930s semi, because the load path runs through the frame rather than through masonry. We open up, record what is there, and let the structural engineer design the opening from the actual construction.

• Steel beam installation to remove the dividing wall
• Structural engineer coordination and building control sign-off
• Level flooring and threshold removal across the whole space

VOA Council Tax stock of properties, March 2025, for all 6 statistical areas in Brentwood. Counts rounded by the VOA.

Two or three things usually come up alongside open-plan conversion on a Brentwood job: home renovation in Brentwood, open-plan conversion in Hornchurch, side return infills, garage conversions, open-plan conversion anywhere in London and RSJ & Load-Bearing Walls.

Why Brentwood Homeowners Choose GS Renovation

An open plan conversion is judged on the finish, not the steel. The beam is hidden, so what you live with is the ceiling line, the floor junction where two rooms meet, the skirting, the lighting and the heating that now has to serve one bigger space. We carry the job from survey through structure to decoration as one contract, which keeps those junctions the responsibility of one firm. The structural engineer we appoint issues the calculations and we build to them. GS Renovation Ltd is fully insured, coordinates the building control application and inspections, and is registered in England, company number 14611254. Quotations are free and without obligation.

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.