MCIAT chartered drawings · Fixed fees across all 33 London boroughs
[email protected]020 7864 7245WhatsApp

Free 2026 London Planning Report — Double Storey Extension Drawings in Sydenham SE26

Rear extension to a Victorian villa in the Sydenham SE26 conservation area, London Borough of Lewisham
Sydenham · SE26 · Lewisham

Double Storey Extension Drawings in Sydenham SE26

Fixed-fee, MCIAT-chartered double storey extension drawings for Sydenham (SE26) homeowners — London Borough of Lewisham validation and local constraints handled from the start.

Free Sydenham planning assessment

Tell us your Sydenham (SE26) address and project. A fixed quote and free planning appraisal land within one working day.

No obligation · No spam · Reply within 1 working day

Sydenham (SE26) in Lewisham is an unusually well-designated hillside suburb: four separate conservation areas — Cobbs Corner, Jews Walk, Sydenham Park and Sydenham Thorpes — cover much of its grand Victorian villa streets. For a neighbourhood this size, that density of designation is exactly why extension and loft projects here need careful handling.

Which of the four conservation areas a Sydenham house sits in matters, and the Sydenham Thorpes estate also carries an Article 4 direction removing specified permitted development rights. Add the steep plots and protected trees, and the route to approval is rarely a simple permitted-development one. We establish the designations for a SE26 address before drawing.

Rear extension to a Victorian villa in the Sydenham SE26 conservation area, London Borough of Lewisham
Isometric illustration of a Sydenham SE26 home double storey extension drawings design
Proposed floor plan
Sydenham SE26

Planning in Sydenham (SE26): what to know before you apply

SE26 is covered by four conservation areas — Cobbs Corner, Jews Walk, Sydenham Park and Sydenham Thorpes — so much of Sydenham's grand villa housing is under close design control, and the Sydenham Thorpes Article 4 direction removes specified permitted development rights within that estate. Steep hillside plots, protected trees and Lewisham's small-HMO Article 4 direction add further considerations.

Typical Sydenham housing stock

Grand Victorian villas and terraces across the Sydenham hills — including the historic houses of Jews Walk and Sydenham Park — with later Edwardian and interwar housing on the higher ground.

Streets we regularly draw for in Sydenham

Sydenham Road · Kirkdale · Westwood Hill · Jews Walk

Double Storey Extension Drawings for Sydenham (SE26) homes: the package and the process

Every double storey extension drawings we prepare for an Sydenham property is drawn to London Borough of Lewisham’s validation standards and tuned to the SE26 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
Extending once vs twice: single versus double storey
OptionWhat it addsTypical fee
Single-storey rear extensionA ground-floor kitchen-diner only, may qualify for permitted developmentsee Rear Extension Drawings, from £1,100
Double storey side or rear extensionTwo rooms across two floors, usually needs full planningFull Planning pack ~£1,600–£2,400
Double storey + Building Regulations (structural)Combined pack including structural calculations for two-floor loads and foundationsPlanning + Building Regs pack ~£2,200–£3,850
Wraparound (rear + side return)Combines two single-storey extensions into one L-shaped ground floorsee Wraparound Extension Drawings, from £2,200

Also in Sydenham SE26

Planning PermissionPlanning DrawingsArchitectural DrawingsBuilding Regulations DrawingsLoft Conversion DrawingsDouble Storey Extension Drawings across LewishamDouble Storey Extension Drawings across London
FAQ

Double Storey Extension Drawings in Sydenham SE26 — FAQs

How much does a double storey extension cost to design in London?+
Double storey extension drawings start from £2,400, covering full planning permission and structural design for the additional floor. A combined planning and building regulations package with full structural calculations runs up to around £3,850, fixed and agreed upfront.
Do I need planning permission to add a second storey?+
In almost all cases, yes. Permitted development rights for two-storey extensions are much tighter than for single-storey work, particularly around boundary distance and roof matching, so we design double storey projects on the assumption a full householder planning application is required.
Will a double storey extension overlook my neighbour's garden?+
That is exactly what planning officers check, using the 45-degree daylight rule alongside boundary set-in and first-floor set-back guidance. Where a new flank window would look directly into a neighbour's garden, we typically specify obscure or high-level glazing to address it before submission rather than after an objection.
Do I need an architect for a double storey extension?+
No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, producing the same council-accepted drawings and in-house structural coordination as an architect, for a fixed fee typically around 30% lower, with structural calculations for the additional floor produced by the same team rather than a separately appointed engineer.
How long does it take to get double storey extension drawings?+
Drawings are typically ready around 7 days from survey. A householder planning application then has a statutory 8-week determination period once submitted.
Do I need planning permission for a side-return extension in Lewisham?+
On the Victorian and Edwardian terraces of Brockley, Forest Hill and Hither Green a single-storey side-return or rear extension can fall within permitted development, so a full application isn't always needed. Conservation areas such as Blackheath, Brockley and Telegraph Hill restrict this. We check your street's designation first and can confirm permitted development with a Lawful Development Certificate where it qualifies.
What does Lewisham's borough-wide HMO Article 4 direction affect?+
Lewisham applies a borough-wide Article 4 direction removing permitted development rights for change of use to an HMO (C3 to C4), so a conversion to a house in multiple occupation needs a full application anywhere in the borough. It doesn't affect a standard family extension or loft, but we confirm whether it applies to your intended use before advising on a route.
Can I convert the loft on my Lewisham terrace?+
Usually, yes. The terraces of Brockley, Forest Hill and Hither Green suit hip-to-gable and dormer loft conversions, which frequently qualify as permitted development within the volume limits. Outside the conservation areas this is often the quickest route. We confirm eligibility against those limits and any designation, then produce the planning and building-regulations drawings.
How long does Lewisham Council take to decide?+
Lewisham determines most householder applications within the statutory eight-week period once validated; conservation cases can attract additional consultation. The dense terraced streets are party-wall-sensitive, so the commonest delay is a drawing query — we prepare submissions to the council's validation checklist to keep them moving.
How much do planning drawings cost in Lewisham?+
We agree a fixed fee before starting, usually around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Lewisham approves. A side-return, a loft and a conservation-area scheme differ in complexity, so we quote once we understand your street and project rather than charging by the hour.
Free Fixed Quote

Get your free Sydenham planning assessment

Tell us your Sydenham (SE26) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.