House Extensions in South Woodford & East London — single-storey, double-storey and wrap-around builds

A house extension is the highest-impact change you can make to a London ground floor — done well, it converts a chopped-up Victorian or 1930s plan into the open kitchen-diner-living space modern families actually use. Done badly, it floods, loses planning at appeal, or sits structurally short of the loads it has to carry.

We build all four common types: single-storey rear (the workhorse), side-return (specifically for Victorian terraces with a passageway down one side), wrap-around (rear + side return combined for maximum ground-floor footprint), and double-storey (adds bedroom or bathroom upstairs as well). The right type for you depends on plot orientation, party wall position, neighbour amenity (rights to light, overshadowing) and what your local authority allows.

Most extension clients are East London families in Wanstead, Walthamstow, South Woodford and Hackney who want a kitchen-diner that opens to the garden, plus often a downstairs WC and utility. We handle the whole package: architectural design, structural calcs, Permitted Development or full planning, Party Wall awards, foundation excavation, structural steels, drainage diversions, glazing, kitchen fit-out coordination and decoration. One contract, one programme, one number to call.

Properly planned bifold/slider opening

Steels and reveals designed around your glazing system from day one — no compromise tracks under exposed beams.

Drainage and soil routed at design stage

We build over agreements (where required) and divert internal drainage before excavation, not after the slab is poured.

Foundations matched to ground conditions

Deep mass concrete or beam-and-block sized to NHBC standards for tree root proximity and clay shrinkage.

Glazing supplied and fitted by us

Bifold, slider, lantern and rooflights all sourced and installed in-house — single warranty, single accountable contractor.

A single-storey rear extension on a typical Victorian terrace involves removing the rear external wall and replacing the load with one or two RSJ steel beams supported on padstones into the side walls. The steels carry the first-floor load above the new opening and the rear wall above the new flat roof. Beam sizes are calculated by a structural engineer against span, load and deflection limits — typical sizes range from 203×133 UB up to 254×254 UC for wider openings.

Side-return extensions are a Victorian-terrace specialty: the side passageway (originally for outside WCs and coal stores) gets enclosed and incorporated into the kitchen, widening the rear room from ~3m to ~4.5m. This usually requires a steel beam carrying the existing rear outrigger wall and careful party wall coordination with the neighbour whose wall now becomes a shared structural element.

Wrap-around extensions combine rear + side-return into one L-shaped footprint — typically the maximum ground-floor build-out you can do on a Victorian terrace. They're particularly effective in Walthamstow, Leytonstone and Hackney where original kitchens are tight and gardens are deep enough to give up 4–5m of length.

Double-storey rear extensions add bedroom or bathroom space above the new ground-floor room. They cost roughly 1.6–1.8× a single-storey of the same footprint, but the cost-per-m² is significantly lower because you're sharing foundations and roof. They almost always need full planning permission rather than Permitted Development.

Glazing choice drives the visual outcome more than any other decision. Bifold doors give maximum opening width but stack against the wall (eats internal/external space). Sliding doors give cleaner sight lines and better thermal performance but a fixed pane never opens. Roof lanterns transform light levels in deeper plans — we typically specify aluminium-framed self-cleaning glazing with U-values around 1.0 W/m²K.

Do I need planning permission for a rear extension?

How long will the extension take on site?

Will my kitchen be out of action during the build?

What about the Party Wall Act?

Will it affect my home insurance or mortgage?

What guarantees apply to the structural elements and the glazing?