Double Storey Extension Drawings in Belgravia SW1X
Fixed-fee, MCIAT-chartered double storey extension drawings for Belgravia (SW1X) homeowners — Westminster City Council validation and local constraints handled from the start.
Belgravia (SW1X) is the Grosvenor estate at its grandest — stucco-fronted terraces and garden squares where the dominant work is careful internal reconfiguration of large townhouses and mansion flats, basement formation, and servicing upgrades rather than the rear extensions typical of outer London. The planning context is among the most demanding in the country, and the drawings have to reflect that from the first line.
Because so much of the stock is listed and every street sits within the Belgravia conservation area, most projects turn on listed-building consent as much as planning, and any lower-ground or basement scheme runs straight into Westminster's strict subterranean policy. We establish the listing grade, the conservation boundary and the Grosvenor estate's separate freeholder requirements before drawing, and prepare the application to Westminster City Council's validation standard.
Planning in Belgravia (SW1X): what to know before you apply
There is no published householder Article 4 direction that changes the picture in SW1X because the real controls are stronger still: pervasive statutory listing, blanket Belgravia conservation-area status and Westminster's restrictive basement policy. Grosvenor estate leaseholders also need freeholder licence for alterations, which we account for alongside the council submission.
Typical Belgravia housing stock
Grand white-stucco terraces and set-piece garden squares laid out for the Grosvenor estate from the 1820s — Eaton Square, Belgrave Square and their tributary streets — behind them cobbled mews and a layer of later mansion flats, much of it statutorily listed and held on long leases.
Streets we regularly draw for in Belgravia
Eccleston Square · Hugh Street · Warwick Way · St George's Drive
Double Storey Extension Drawings for Belgravia (SW1X) homes: the package and the process
Every double storey extension drawings we prepare for an Belgravia property is drawn to Westminster City Council’s validation standards and tuned to the SW1X constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.
A double storey extension builds a second floor above a single-storey side or rear addition, typically adding a bedroom and bathroom upstairs over a widened kitchen or reception room below. Because the foundations and roof of a single-storey extension already carry most of the fixed cost of building, adding a floor on top is often the most cost-effective way to gain two rooms rather than two separate projects. The trade-off is scrutiny: a two-storey addition sits closer to eye level with neighbouring windows and gardens, so councils examine massing, roofline and boundary distance more closely than they would a single-storey extension.
DrawingsDirect draws double storey side and rear extensions for full planning and building regulations, with structural calculations for the additional floor load and foundations produced in-house by our MCIAT-chartered team, on a fixed fee. If a single storey is enough, see our Rear Extension and Side Return Extension pages, or combine both with a Wraparound if you are extending sideways as well as up.
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
| 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 Belgravia SW1X — 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 works in Westminster?+
I live in a mansion block — what extra consent might I need?+
Will I need a Basement Impact Assessment in Westminster?+
How long does Westminster City Council take to decide?+
How much do planning drawings cost in Westminster?+
Get your free Belgravia planning assessment
Tell us your Belgravia (SW1X) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.