
House Extension Drawings in Barnes SW13
Fixed-fee, MCIAT-chartered house extension drawings for Barnes (SW13) homeowners — London Borough of Richmond upon Thames validation and local constraints handled from the start.
Barnes (SW13) is an unusually intact riverside village in Richmond, and it is heavily conservation-controlled: four conservation areas — Barnes Common, Barnes Green, Castelnau and Madrid Road — cover most of the housing. Whether a property sits inside one of those boundaries, and often it does, is the single biggest factor in how an extension, loft or elevation change is designed and assessed.
The Thames wraps the neighbourhood on two sides, so riverside houses along Lonsdale Road and the Terrace also carry flood-zone considerations, and Barnes Common is protected metropolitan open land. We map a Barnes property against the conservation, flood-zone and open-land boundaries first, then design the drawings to Richmond's residential and conservation guidance so the application is validated without a query.


Planning in Barnes (SW13): what to know before you apply
SW13 has no householder Article 4 direction, but its four conservation areas mean permitted development cannot be assumed across most of Barnes, and riverside properties along Lonsdale Road sit within the Thames flood zone — both are checked before we recommend a route.
Typical Barnes housing stock
Victorian and Edwardian terraces and cottages around Barnes Green and the village, the grand Italianate semi-detached villas along Castelnau toward Hammersmith Bridge, and riverside houses fronting the Thames on Lonsdale Road.
Streets we regularly draw for in Barnes
Church Road · Castelnau · White Hart Lane · Lonsdale Road
What SW13 is actually built of
Measured from 328 classified residential buildings in SW13, not from a description of the area.
Barnes SW13 housing mix
Residential building form across the SW13 postcode district, from 328 classified buildings.
| Attached on more than one side | 48% |
|---|---|
| Attached on one side | 47% |
| Detached | 5% |
| Median building footprint | 75 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 1.29 |
| Buildings classified | 328 |
Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.
House Extension Drawings for Barnes (SW13) homes: the package and the process
Extension drawings are read for their dimensions. The proposed plan needs depth measured from the original rear wall — not from a previous extension — eaves and ridge heights taken from existing ground level, and the distance to each boundary marked. A site plan showing how much garden remains is what an officer reaches for when the amenity question comes up.
We draw the existing building accurately first, because everything else is measured from it. Where the original footprint has already been added to, that history goes on the drawing: it decides which allowances are still available and it is the first thing an officer checks against the council's own records.
The plot decides the extension type long before taste does. A mid-terrace has depth to work with and an alley if it is lucky; a semi has one clear flank; a detached house can go wide. Reading the building form first is what stops a design being drawn that the plot cannot take.
Which extension types do you draw?
Every London extension is shaped by the plot, the neighbours and the borough's design guidance. We draw them all.
Rear extension
A single-storey rear extension is often permitted development within depth limits — ideal for an open-plan kitchen-diner.
Side-return
Fills the alley beside a Victorian terrace, widening the ground floor without losing garden.
Wraparound
Combines a rear and side-return extension for a transformative ground floor, usually needing planning permission.
Double-storey
Adds space above and below, subject to tighter scale and neighbour-impact scrutiny.
Basement
Creates space downward where footprint is limited, with structural and party-wall care.
Do I need planning permission for a house extension in London?
Single-storey rear extensions within permitted development limits (up to 6m for terraced/semi-detached homes under the larger-home scheme, subject to neighbour consultation) may not need a full application. Wraparounds, double-storeys and anything in a conservation area usually do. We assess your plot and recommend the right route before drawing. The current depth, height and eaves limits are set out in full in the guide to planning permission for a rear extension, and where you would rather one practice ran the design, the application and the building-regulations stage together, Architectural Drawings covers that full scope.
How do you maximise the footprint the council will approve?
We know each borough's depth, height and daylight standards, so we design to the edge of what will be approved rather than guessing — and we check the 45-degree neighbour daylight rule and any rear building line before submission. Where a plot is tight we test a permitted-development scheme against a slightly larger householder application and show you the trade-off in space, cost and timescale, so the drawn scheme is the one that actually maximises value rather than just floor area.
| Extension | Typical route | Package | Fee from |
|---|---|---|---|
| Single-storey rear | Permitted development / householder | Planning + building regs | £1,100 |
| Side-return | Householder planning | Planning + building regs + structural | £1,600 |
| Wraparound | Householder planning | Full package + structural | £2,200 |
| Double-storey | Householder planning | Full package + structural | £2,400 |

House Extension Drawings in Barnes SW13 — FAQs
How far can I extend without planning permission in London?+
Do extension drawings include structural calculations?+
How long do extension drawings take?+
Will my rear extension need a party wall agreement?+
Can I extend a house in a conservation area?+
Do I need planning permission for an extension in Richmond?+
My Richmond home is near the river — does flood risk affect my application?+
What does Richmond's Article 4 coverage mean in practice?+
How long does Richmond Council take to decide?+
How much do planning drawings cost in Richmond?+
Get your free Barnes planning assessment
Tell us your Barnes (SW13) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.