Open-Plan Conversions Merton

GS Renovation creates open-plan living across Merton, opening up the compartmented layouts of Wimbledon, Mitcham and Morden's terraces into bright kitchen-diners and flowing reception spaces. We combine engineer-sized steel beams with careful finishing, whether you want a full knock-through, a broken-plan scheme or a Crittall divider.

In Merton, a knock-through finished as one room typically costs £3,000 to £8,000 or more, including the steel beam (indicative London ranges, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Merton: 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 Merton 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 Merton 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.

Knock-throughs in Merton's period homes

The classic Victorian terrace around Wimbledon was built as a series of small rooms, and the walls between the front reception, the middle room and the rear closet-wing kitchen are usually load-bearing. To join them into one open space we have an engineer size a steel beam for each opening, set it on padstones, prop the floors above and remove the walls in controlled stages so the ceiling never drops.

Not every home wants a single vast room. In many SW19 and SW20 houses we create broken-plan layouts instead, keeping a structural pier or a low return so the kitchen and dining zones read as one but retain some definition. Where clients want light without full openness, a Crittall-style glazed divider set into an engineered opening gives a bright, defined kitchen-diner with the industrial look these period homes carry well.

Housing in Merton

Merton's housing, as the Council Tax list records it, is about 87,830 homes: 58% houses, 42% flats, with 26% pre-1919, 37% interwar and 36% built since 1945. Terraced houses make up 43% of homes here, and opening up a terrace in Merton usually lands one beam end on the party wall.

Scoping every wall at once for a Merton open plan

Merton has a fixed charge for the standalone removal of an internal wall in a single-dwelling domestic building. For more than one wall or significant structural alterations, the building control charge is worked out from Table C using the cost of works instead. An open-plan conversion crosses that line as soon as more than one wall comes out, for example to join three rooms into one. So the cost of works has to be known when the application goes in, which means the scope is agreed and priced first.

Decide the whole Merton layout before applying, including any wall you might take out later. Removing one wall now and a second next year means two applications and two rounds of inspection, and the first beam may be sized without the load the second opening puts on it. The structural engineer we appoint can design both openings together and the work can still be phased. Where a house built between 1919 and 1939 has its stairs in an enclosed hall, say at survey whether it is part of the plan, because opening it changes the escape route from upstairs.

Consents and finish for Merton kitchen-diners

Opening up the ground floor is structural work, so it is governed by the Building Regulations and Merton Council's building control inspects the beams and signs off the completion, rather than any planning application. Internal open-plan work does not need planning permission; a listed home is the exception, where removing walls needs listed building consent. We manage the inspections and hand over building control's completion certificate and the engineer's calculations.

Because these beams often bear into the party wall shared with the neighbour, the Party Wall Act applies and you serve notice as building owner before work starts, which is standard on Merton's continuous terraced rows. We then finish the space properly: beams boxed in or flush, floors levelled across the old wall lines, and plaster, skirting and services made good so your new kitchen-diner feels like it was always one room.

• Ventilation and extraction planned for an open kitchen
• Beam depth checked against existing ceiling heights
• Radiator relocation and underfloor heating in the new layout

VOA Council Tax stock of properties, March 2025, for all 25 statistical areas in Merton. Counts rounded by the VOA.

Alongside open-plan conversion in Merton, the pages that usually help next are home renovation in Merton, our Merton area guide, side return infills, garage conversions, open-plan conversion across London and Kitchen Island Guide.

Why Choose GS Renovation in Merton

Merton homeowners choose GS Renovation for open-plan work because one team takes it from engineer's design to finished room: beam sizing by the engineer we appoint, safe staged demolition, building control sign-off and a clean plastered finish. We protect your home while we work, keep the dust and disruption down, and bring our founder's 30+ years on the tools.

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.