An open plan conversion in an Epsom house is one continuous piece of work: the engineer's design, the propping, the steel, the inspections and the finishing. Where the space is being won by extending as well as by opening up, Epsom and Ewell's householder guidance sets the depth the design has to sit inside. We carry the whole job, with one point of contact.
How far you can go back before the guidance stops you
3.25 metres, on a semi detached or terraced house. Epsom and Ewell's Householder Applications Design Guidance sets that as the maximum projection for a single storey rear extension onto a semi detached or terraced house, to protect the outlook and daylighting of the adjoining property. Open up into a rear extension of that depth and the finished room is the original back room plus 3.25 metres, not plus whatever the sketch shows.
That number should shape the layout before the layout is drawn. It decides where an island can sit, where the beam line runs and how wide the opening between the two spaces can be. We would rather set it out at the survey than redraw a kitchen after a planning officer has read the guidance back to you.
Narrow terraces carry a further limit
Going up as well as back may not be available to you. Epsom and Ewell's householder guidance warns that on a narrow width terraced property a two storey rear extension may not be possible, because of the loss of daylight and outlook to the neighbours' main rear ground floor window. That closes one route to a larger open plan ground floor and pushes the answer back towards a single storey solution.
It also changes the structure. A single storey rear extension with a wide opening into the original house puts the load on one beam line at ground floor. The engineer we appoint sizes that beam and specifies its bearings, and we build to the design. Where the opening reaches a party wall, the notice under the Party Wall etc. Act 1996 is your duty as building owner, and we have the structural detail ready for your surveyor.
What the age of Epsom's housing means for an opening
The largest single group was built in the 1930s. Valuation Office Agency figures for 31 March 2025 record 11,720 of the 32,980 Epsom and Ewell dwellings with a known build period as built between 1930 and 1939, the largest single band by a wide margin. The next largest band, 1955 to 1964, holds 3,220 dwellings.
Houses built in that period share a familiar ground floor arrangement: a front room, a back room, a chimney breast between them and a kitchen behind. Opening that up is one wall, one beam and one set of bearings, which is the job the indicative ranges describe. It is still not a job to start without calculations, because what the wall carries above is settled by inspection rather than by assumption.
- Lighting, heating and electrical reconfiguration
- Rooflights and glazed roofs to bring light deep into the plan
- Kitchen island services routed through the new floor
- Broken-plan layouts and Crittall-style glazed dividers
- Zoned lighting circuits and dimming for a multi-use room
Why Epsom Homeowners Choose GS Renovation
An open plan conversion is several jobs that have to happen in one order, so we do not split them across firms. We appoint the engineer, prop and cut, seat the steel, coordinate the building control inspections and finish the room. That gives you one point of contact and one firm answerable for the result, from the first survey through to the completion certificate. Fully insured, free quotations with no obligation.
- A dedicated project manager from first survey to handover
- Dust screens and floor protection in occupied homes
- Photographs kept at each stage for your records
- Clean, tidy and reliable tradespeople
- The house kept usable while the opening is formed in stages
- Beam depth checked against ceiling heights before you commit