
Double Storey Extension Drawings in Sidcup DA14
Fixed-fee, MCIAT-chartered double storey extension drawings for Sidcup (DA14) homeowners — London Borough of Bexley validation and local constraints handled from the start.
Sidcup's DA14 streets run from the 1930s semis of the Cray valley to the historic core of Foots Cray village, and most of our work here is rear kitchen extensions and loft conversions that add space to those bay-fronted family homes without losing garden depth.
If your home sits inside the Foots Cray Conservation Area the permitted-development shortcuts narrow, so we always confirm the boundary line first and then advise whether a project runs under permitted development or needs a full householder planning application to Bexley.


Planning in Sidcup (DA14): what to know before you apply
Most DA14 extensions and lofts outside the conservation area proceed under permitted development or a lawful development certificate. Inside the Foots Cray Conservation Area, or where a home backs onto Foots Cray Meadows or carries protected trees, a full householder planning application to Bexley is the safer route. We check the boundary and tree constraints before recommending either path.
Typical Sidcup housing stock
DA14 is dominated by 1930s bay-fronted semis and terraces along the Cray valley, wrapped around the older historic core of Foots Cray village where Victorian and Georgian buildings survive on the High Street. Larger detached and inter-war housing sits on the roads backing onto Foots Cray Meadows.
Streets we regularly draw for in Sidcup
High Street · Rectory Lane · Maidstone Road · Church Road
Double Storey Extension Drawings for Sidcup (DA14) homes: the package and the process
Every double storey extension drawings we prepare for an Sidcup property is drawn to London Borough of Bexley’s validation standards and tuned to the DA14 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 Sidcup DA14 — 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 an extension in Bexley?+
Can I build a bigger extension because Bexley plots are larger?+
What extra control applies in Old Bexley Village or around Danson Park?+
How long does Bexley Council take to decide?+
How much do planning drawings cost in Bexley?+
Get your free Sidcup planning assessment
Tell us your Sidcup (DA14) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.