GS Renovation designs and builds extensions on the Victorian and Edwardian terraces of Harlesden, from rear and side-return additions to full wrap-arounds and double storeys. With over 30 years of building in NW10 and across Brent, we handle the groundworks, steelwork, roof and fit-out as one accountable project.
Side-return and rear extensions in Harlesden
The bay-fronted terraces around Harlesden almost always have a side return, that narrow strip of yard alongside the original rear closet wing. Filling it in is the classic NW10 project, widening a cramped galley kitchen into a bright open-plan kitchen-diner. We dig and pour the new foundations, build the flank wall, and install steel beams to carry the existing structure where the old external wall comes out.
A rear extension pushes the ground floor further into the garden, and a wrap-around combines both moves for a generous L-shaped living space. We match brickwork and detailing to the Victorian and Edwardian character where it shows, add rooflights or a lantern for daylight, and manage the drainage runs and party wall matters that come with building tight against the neighbours on either side.
Planning and permitted development in Brent
Whether your Harlesden extension is permitted development or needs a full planning application depends on the property and the size of the build. Many single-storey rear extensions on these NW10 terraces fall within permitted development, but double storeys, larger footprints, and any home in a conservation area or that has already been extended usually need permission from Brent Council. We assess this at the outset so there are no surprises.
Whichever route applies, the structural side is controlled under building regulations, so foundations, beams and the roof are all inspected and signed off by building control. Because these terraces share party walls, we also handle the Party Wall Act notices for the excavation and any work against the boundary. One team ties the planning position, the structure and the finished rooms together.
Inspections and drains on an NW10 extension
An extension is inspected at set stages rather than once at the end, and knowing the list helps you follow progress. Building control wants to see the trench before concrete goes in, since foundation depth on London clay depends on what is actually found and on any tree within influencing distance. Then the damp-proof course and oversite, the cavity trays and lintels, the insulation before it is covered, and the drainage before it is backfilled.
Drains catch people out. Many Harlesden terraces have a public sewer running across the back gardens, and building over or within three metres of it needs a build over agreement from Thames Water, applied for well before the digger arrives. Where an existing inspection chamber ends up inside the new footprint, it has to be sealed and made accessible to a proper detail. We deal with the applications rather than leaving them to you to chase while the site waits.
- Trial holes to set foundation depth near drains and trees
- Flat and pitched roofs with rooflights or lanterns
- Architectural drawings and structural engineer coordination
- Insulation, airtightness and thermal detailing to regulations
- Scaffolding, site set-up and safe access on tight London plots
The GS Renovation Difference in Harlesden
Harlesden owners choose GS Renovation because we manage the whole extension, from the first foundation to the final coat of paint. We advise honestly on whether your NW10 build is permitted development or needs Brent Council planning, engineer the steel, respect the shared party walls and keep an occupied home liveable. Thirty years in Brent stands behind every project.
- Free follow-up visit after completion if anything needs attention
- Paperwork and certificates handed over for when you sell
- Brick and mortar matched to the existing elevation
- Straight advice on what is and is not worth spending money on
- Drainage diverted or built over with the right approval in place
- Party Wall notices served for excavation near a neighbour's wall