Wandsworth
We design rear house extensions for Putney homes, from a single-storey garden-facing addition on a bay-fronted terrace near the Upper Richmond Road to a wider rear projection on a West Putney villa. The governing question is always the same: how far the back of the house can push into the garden before it erodes garden depth, neighbour daylight or the plot itself. That rear building line — not the room inside it — is where our drawings and Wandsworth planning strategy start.
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Practice leadership
Eyal Moran, Director and Lead Architect, is an ARB-registered architect, leading design judgement, planning strategy and technical coordination across client projects.
Verify on the Architects RegisterThe short answer
Yes. Rear extensions to Putney houses are achievable, but they sit within Wandsworth and often need a full householder application rather than permitted development. Success turns on the rear building line — a projection depth that protects garden space and the neighbour's daylight, held subordinate to the host and, where a conservation area applies, to its character.
Planning at a glance
Putney
| Local planning authority | London Borough of Wandsworth |
|---|---|
| Likely approval route | Householder planning application or permitted development, depending on conservation status, listing and property type — confirmed for the exact address before drawings begin |
| Statutory determination time | 8 weeks for most householder applications (13 weeks for major applications) |
| Typical drawing package | £2,250–£3,250 inc. VAT, fixed fee. Find my package → |
The single most consequential decision on a Putney rear extension is where the new back wall lands. Every other choice — glazing, roof, internal layout — follows from how far the extension projects beyond the existing rear building line, and that is what a Wandsworth case officer scrutinises first. The useful question is never how much room you could add but how far the house can push into the garden before the remaining outdoor space feels compromised, a neighbour's rear windows lose daylight, or the plot reads as over-developed. We test candidate depths in section against the garden that would be left, the boundary walls and the position of the neighbours on either side, then fix a projection that is both liveable inside and defensible when the application is assessed. On evidence, not optimism, the footprint is agreed before any elevation is drawn.
Putney's stock makes this a genuinely different problem street by street. On a late-Victorian bay-fronted terrace between the Upper Richmond Road and the Heath, the original plan usually has a rear closet wing and a slot of garden beside it, and a rear extension is about squaring that stepped back elevation into a full-width or partial-width addition while holding a workable projection. On an Edwardian or grander villa in West Putney the plot is deeper and the back garden more generous, so the constraint shifts from raw depth to the relationship with a semi-detached neighbour and the gap between houses. A riverside or Embankment house brings its setting into play more prominently still, where boundaries and views weigh as heavily as the projection itself. The same drawing template does not serve all three, so we start from your house type, its plot and the depth of garden actually behind the original rear wall rather than from a standard extension footprint that ignores those differences.
On a terrace, the neighbour relationship almost always governs the depth. Because the houses are attached and their rear elevations sit in a shared rhythm, a projection that would be unremarkable on a detached house can overshadow the adjoining home or block daylight to its nearest rear window. A full-width rear extension that removes the original return gives the most usable space but pushes hardest against that boundary, so we often test it against a stepped or partial-width alternative that keeps light reaching the neighbour. Wandsworth weighs the effect on adjoining amenity heavily, and a 45-degree relationship to the neighbour's rear windows is a common informal check, so we model the addition against both boundaries early and let that evidence set how far the back wall can reasonably go.
The larger West Putney villas open up options a terrace cannot carry. A deeper garden can absorb a more generous single-storey projection, and on some detached and semi-detached houses a two-storey rear addition becomes realistic — but the second storey changes the assessment entirely. First-floor windows introduce outlook and overlooking over a neighbour's garden, and the sense of enclosure over an attached property is far more sensitive on a semi-detached pair that shares a flank wall. The spacing between the villas is part of what gives West Putney its grain, so a rear addition that reads as bulk filling the gap is resisted where a subordinate, well-set-back form is not. We advise at feasibility which storey height a given villa and plot can actually support before the design commits to it, and where two storeys are not defensible we look at whether a deeper single storey, set well back from the shared boundary, delivers the space without the overlooking that sinks a scheme.
Riverside and Embankment houses are where setting does the most work. A rear extension here is generally hidden from the street, but the garden setting, the boundary treatment and the way the back of the house is read from surrounding space carry more weight, and where the property sits within the Putney Embankment conservation area the materials and the depth behind the original building line are assessed against that character. We keep the addition subordinate to the host — resolving how render, London stock brick or a restrained contemporary element sits against the existing rear wall, and detailing the junction so the extension reads as an addition rather than a competing mass. Whether conservation controls apply is confirmed for the exact address, because that determines how much the setting constrains the projection.
Daylight, right to light and the party wall process then have to be built into the scheme rather than discovered late. Wandsworth 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 settle, so where the addition approaches a neighbour's window we flag it early. Because a rear extension excavates for foundations close to a boundary, the Party Wall etc. Act 1996 typically applies too. From there the route is coordinated: we survey the house, test the projection against these constraints, produce the planning drawings, and once the principle is settled prepare the building regulations package covering structure, drainage, insulation and the rest for construction.
Local analysis
Confirm conservation area status, then design against Wandsworth Housing SPD themes for extensions and roof works. Neighbour amenity sections and party wall dual flanks are programmed early. After permission, building regulations drawings turn the approved envelope into a buildable package.
On a Putney rear extension the projection depth is the decision everything else hangs on, and it is the first thing Wandsworth weighs. The defensible depth is not a fixed number but a balance: the garden that remains behind the new wall, the daylight reaching adjoining rear windows, the height near the boundary and the effect on the rhythm of rear elevations along the street. A depth that a deep West Putney plot absorbs comfortably would over-develop a compact terrace near the high street, so the same figure is not available to every house. We model the addition in section against both boundaries and the retained garden at feasibility, so the footprint is agreed on evidence before a single elevation or glazing line is drawn.
The bay-fronted terraces between the Upper Richmond Road and the Heath usually began with a rear closet wing and a narrow strip of garden beside it, and the tempting move is to square the plan into a full-width rear room. That gives the most usable space, but because the houses are attached it also pushes hardest against the neighbour's daylight and outlook, and Wandsworth weighs that adjoining amenity heavily. A 45-degree line to the neighbour's nearest rear window is a common informal check. So we test the full width against a stepped or partial-width alternative that keeps light reaching next door, model both against the shared boundary, and let that comparison — rather than the maximum footprint — decide how the back of the house is resolved. That evidence also gives the application a clearer case at Wandsworth, because the retained daylight to the neighbour is shown rather than merely asserted.
The grander West Putney villas and the riverside and Embankment houses change the emphasis from raw depth to setting and spacing. A deeper villa garden can carry a more generous single-storey projection, and sometimes a two-storey rear addition, but the gap between semi-detached and detached houses is part of what the area's grain protects, so a rear form that reads as bulk filling that gap is resisted where a subordinate one is not. On a riverside or Embankment property the garden setting and boundary treatment carry more weight, and where the address sits within a conservation area the materials and the depth behind the original building line are assessed against that character. We keep the addition subordinate and confirm whether conservation controls apply before committing the design, resolving how the materials meet the existing rear wall and how the new boundary and garden edge are treated so the extension settles into the setting rather than announcing itself across it.
Thinking about a project in Putney?
Send the address and a short description. We will confirm the likely approval route and the drawings your project needs.
Local planning
Putney sits wholly within the London Borough of Wandsworth, which is the single planning authority for the whole area — there is no borough boundary to check here as there is in some neighbouring places. A rear extension is assessed against Wandsworth's adopted policies and, where the specific address falls within a conservation area, against the relevant appraisal. Because the rear building line and garden depth vary so much across Putney's stock, the same projection is not equally available to a compact terrace near the high street and a villa in West Putney; we establish the defensible depth for your house before advising on a route.
Permitted development can allow some single-storey rear extensions to houses, but those rights are frequently curtailed on conservation-area land and can be removed by an Article 4 direction, and they never apply to flats or maisonettes. We treat permitted development as something to confirm for the exact address rather than assume, and where the position is genuinely open we can test it through a lawful development certificate rather than relying on it. For most Putney rear extensions we plan for a full householder application to Wandsworth from the outset.
A rear extension usually sits close to at least one boundary, so the Party Wall etc. Act 1996 runs alongside planning as a separate national process. Building on the line of junction with a neighbour, or excavating for foundations within three or six metres of a neighbour's structure, triggers notices that are independent of the planning decision and take time to serve and resolve. On Putney's tightly built terraces the attached neighbour is almost always notifiable, so we identify the parties and programme the party wall stage early rather than letting it delay a start on site.
Two conservation areas are recognised in Putney — West Putney and the Putney Embankment — and their appraisals place weight on the riverside setting, established building lines and traditional materials. A rear extension is generally less publicly visible than a front alteration, but where a property sits within one of these areas the projection's relationship to garden walls, the depth left behind the original building line and the materials against the host brickwork are still assessed against that character, so whether your address falls inside a conservation area should be confirmed before the design is fixed.
Even outside a designated area, the grain of Putney's back gardens — the rhythm of rear elevations along a terrace and the spacing between the West Putney villas — informs how far a rear addition can go, so we design to the specific street rather than to a generic depth.
For the wider local-authority picture — policies, timescales and application routes — see planning in Wandsworth.
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Extensions & Renovations
Planning & Consents
Technical & Building Regulations
Leasehold & Licence to Alter
Nearby
Send us your Putney address and a short description of the rear extension you have in mind. We will confirm whether a conservation area applies, test how far the back of the house can project against your garden depth and the neighbour relationship, and set out the design, approvals and drawings your project will need.
