Double Storey Extension Drawings in Southfields SW18
Fixed-fee, MCIAT-chartered double storey extension drawings for Southfields (SW18) homeowners — London Borough of Wandsworth validation and local constraints handled from the start.
Southfields (SW18) is the celebrated 'Grid' of late-Victorian terraces packed between Southfields station and Wimbledon Park, a stone's throw from the All England Club. The typical projects are glazed side-return kitchen extensions, full-width rear extensions and L-shaped loft conversions with rear dormers — all within Wandsworth's well-trodden householder framework.
Because much of the Grid lies within conservation areas such as Rusholme Road, Sutherland Grove and Wimbledon Park Road, front elevations, roof forms and materials are closely controlled and permitted-development rights are often reduced. We produce drawings that keep the terrace rhythm, front bays and valley-roof lines intact to the standard Wandsworth conservation officers expect, and coordinate party-wall matters across the shared boundaries.
Planning in Southfields (SW18): what to know before you apply
No published householder Article 4 direction in Southfields, but the numerous conservation areas across the Grid remove some permitted-development rights and tighten control on roof alterations, front changes and materials. Rear extension depth on the long narrow plots is assessed for daylight, outlook and the neighbouring building line.
Typical Southfields housing stock
Southfields is defined by 'The Grid' — dense, uniform two- and three-storey late-Victorian terraces with bay fronts, valley roofs and long narrow gardens, many split into flats. The regularity of the terraces makes rear side-returns, full-width rear extensions and roof conversions the staple projects.
Streets we regularly draw for in Southfields
Keswick Road · Merton Road · Southfields Road · Haldon Road
What SW18 is actually built of
Measured from 440 classified residential buildings in SW18, not from a description of the area.
Southfields SW18 housing mix
Residential building form across the SW18 postcode district, from 440 classified buildings.
| Attached on more than one side | 70% |
|---|---|
| Attached on one side | 25% |
| Detached | 5% |
| Median building footprint | 71 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 1.99 |
| Buildings classified | 440 |
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.
Double Storey Extension Drawings for Southfields (SW18) homes: the package and the process
At first-floor level the drawings have to answer for daylight, privacy and massing. That means proposed elevations showing every new window with its position relative to the boundary, a section taken through the extension and the neighbouring building, and a roof form drawn to sit below the existing ridge rather than compete with it.
We draw the neighbouring property alongside your own, because the officer's assessment is comparative — the effect on their windows and outlook is the test. Setting the first floor in from the boundary, and showing that set-back as a dimension, resolves most objections before consultation begins.
At first floor the boundary relationship decides everything. A detached house has room to set the addition in on both sides; a semi has one shared wall and one clear flank; a mid-terrace can usually only go to the rear, where the effect on both neighbours has to be drawn.
Do I need planning permission for a double storey extension in London?
Almost always. Permitted development rights for two-storey extensions are far more restrictive than for single-storey work, particularly on how close the new structure can come to a boundary and how closely its roof pitch and eaves height must match the existing house, so most double storey projects are drawn and submitted as full householder planning applications rather than relying on permitted development.
Where the property sits in a conservation area or is subject to an Article 4 direction, any remaining permitted development allowance for a second storey is typically removed entirely, reinforcing the need for a full application. We check your property's status and your borough's design guidance before drawing.
How do councils control the impact of a double storey extension on neighbours?
Because a second storey introduces new windows and massing at first-floor level, London boroughs apply design guidance aimed specifically at protecting neighbouring light, privacy and outlook.
- The 45-degree rule, tested at neighbouring windows, to check the extension does not block an unreasonable amount of daylight
- A common design expectation that a two-storey side extension is set in roughly 1 metre from the shared boundary, rather than built hard against it
- A first floor commonly set back from the ground floor front elevation, so the upper storey reads as subordinate to the main house from the street
- Obscure or high-level glazing on flank walls facing directly into a neighbour's garden or windows, to limit overlooking
Matching the roofline and materials
Planning officers assess a double storey extension heavily on how convincingly it reads as part of the original house rather than an addition bolted onto the side. Our drawings match ridge height, roof pitch, eaves detail and brick or render finish to the existing building wherever the design brief allows, which is consistently one of the strongest factors in securing approval without delay or redesign. Where a subtly contrasting material is proposed instead — a different brick tone, or a zinc or slate roof against a tiled original — we set it out clearly on the elevations so the design intent reads as deliberate rather than a mismatch, which is how most London boroughs prefer a genuine design statement to be presented.
| Option | What it adds | Typical fee |
|---|---|---|
| Single-storey rear extension | A ground-floor kitchen-diner only, may qualify for permitted development | see Rear Extension Drawings, from £1,100 |
| Double storey side or rear extension | Two rooms across two floors, usually needs full planning | Full Planning pack ~£1,600–£2,400 |
| Double storey + Building Regulations (structural) | Combined pack including structural calculations for two-floor loads and foundations | Planning + Building Regs pack ~£2,200–£3,850 |
| Wraparound (rear + side return) | Combines two single-storey extensions into one L-shaped ground floor | see Wraparound Extension Drawings, from £2,200 |
Double Storey Extension Drawings in Southfields SW18 — FAQs
How much does a double storey extension cost to design in London?+
Do I need planning permission to add a second storey?+
Will a double storey extension overlook my neighbour's garden?+
Do I need an architect for a double storey extension?+
How long does it take to get double storey extension drawings?+
Do I need planning permission for a side-return extension in Wandsworth?+
What does Wandsworth's basement Article 4 direction mean for me?+
How long will Wandsworth take to decide my application?+
Can you design an extension for a converted flat near the commons?+
How much do Wandsworth planning drawings cost?+
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