A rear extension in Richmond begins with the existing rear building line and the depth of garden behind it. The Georgian, Victorian and family houses here often have generous plots, which can tempt an ambitious footprint, but the useful question is how far the addition can project before it erodes garden amenity, overshadows a neighbour or reads as an over-development of the plot. We survey the back of the house, plot the neighbouring rear walls on either side and test single-storey depths in section against the daylight reaching adjoining windows, so the projection we take to planning is set on evidence rather than optimism.
Many Richmond period houses already carry a back-addition outrigger — a narrower rear wing beside a side passage. A full-width rear extension squares off the plan behind that original return, bringing the rear wall out to a single line across the width of the house. The move is powerful because it converts a broken-up rear into one deep garden-facing room, but it changes the relationship to both side boundaries at once, so the flank walls, the rights of light to neighbours on either side and the party-wall position all come into the assessment together rather than one at a time.
The choice between a single and a two-storey rear extension changes the planning question entirely. Single-storey additions are judged largely on garden impact and neighbour daylight and are the most common route here. A two-storey rear addition — realistic on some of the larger detached and semi-detached houses — brings first-floor outlook, overlooking and a greater sense of enclosure over a neighbour's garden into play, and is far more sensitive on a semi-detached pair sharing a boundary. We advise early which storey height a given house and plot can carry before the design is committed to a submission.
Richmond's setting adds a layer that a plain suburban plot would not. The borough's protected views and its riverside, Green and park context mean the roofscape and upper massing of a rear extension can matter even at the back of a house, particularly on elevated or river-facing ground where a two-storey addition or a tall parapet might read within a longer view. Where the property sits within a conservation area or a protected-view corridor, we keep the rear form low and quiet — controlling ridge and parapet heights and stepping the massing down toward the boundaries — so the addition does not intrude on the setting the borough is protecting.
Daylight and right to light deserve attention from the first sketch. The borough assesses daylight and sunlight to neighbouring windows using the established BRE tests, and a well-judged section — holding the height down near the boundary and stepping the roof away from the neighbour — usually keeps a rear extension within them. Right to light is a separate civil matter that a planning consent does not resolve, so where a full-width or two-storey rear addition approaches a neighbour's window we identify it early and design to it, rather than letting it surface once the scheme is already committed.
From there the route is a coordinated one. We survey the house, test the rear building line against the planning, daylight and setting constraints, and develop a design a Richmond case officer can support, then produce the planning drawings and, once the principle is settled, the building regulations package covering structure, insulation, drainage and — on lower-lying riverside ground — floor levels and foundation design. Because a rear extension is built against the boundaries, the Party Wall etc. Act 1996 typically applies, so we identify the notifiable neighbours on either side early and coordinate with a party wall surveyor to keep the build programme intact.
