If you own a Victorian or Edwardian terrace in London, there is a good chance you have a side return – the narrow strip of outdoor space running alongside the back addition, usually 1.5 to 3 metres wide and often doing nothing but holding bins. Building over it is one of the highest-impact changes you can make to a period house.
What you gain
- A cramped galley kitchen becomes a wide, square kitchen-diner – the single biggest change to how the ground floor feels.
- A glazed roof or rooflights bring daylight into the middle of the house, which is normally the darkest part of a terrace.
- Room for an island, a dining table, or bi-fold doors onto the garden.
The floor area added is modest – typically 8 to 15m² – but because of where it sits, it transforms the layout rather than just adding a room.
Do you need planning permission?
Many side return infills are permitted development as a single-storey side extension, provided they stay within the height limits and do not extend beyond the original side wall by more than allowed. However, side extensions are more likely to need permission in conservation areas, and Article 4 directions can remove the right entirely. Always check with your council before designing.
What it costs
Around £40,000 to £70,000+ in London, depending on the glazing (rooflights versus a structural glass roof), whether a new kitchen is included, and the finish. Combining it with a rear extension for a full wrap-around costs more but delivers the largest open-plan space.
Is it worth it?
- Yes, if you have an unused side return and a dark, narrow kitchen – the improvement to light, space and flow is out of proportion to the floor area, and it adds strong value.
- Less so, if your kitchen is already a decent width, you have no side return, or you would lose the only sensible side access to the garden.
Arkivon Group designs and builds side return and rear extensions across London on a fixed price. Book a free site visit and we will tell you what your side return could become and what it would cost.