Planning and building regulation drawings in Sidcup (DA15)
DA15 mixes housing of very different ages. Halfway Street and Burnt Oak Lane are lined with small cottages from the seventeenth and eighteenth centuries, and the conservation area there also takes in Holy Trinity Church. Longlands Road is an inter-war estate of hipped-roof semis that has barely been altered since it was built. Broad Edwardian and 1930s suburban avenues around Blackfen and Lamorbey fill the ground in between, and Blackfen Road is among the district's other streets.
- MCIAT chartered technologists
- London Borough of Bexley granted 95% of 939 householder applications
- Drawings in about 7 days
Blackfen itself is a 1930s Metro-land suburb of uniform interwar semis, laid out in consistent bay-fronted, hip-roofed pairs along broad avenues. Wellington Avenue, Rutland Avenue, Cavendish Avenue and Montrose Avenue are among its streets. On this kind of house the common projects are extending at the back, converting the loft and changing a hipped roof to a gable, and how the new work sits beside the matching house next door is a regular design question. Shared party walls between the pairs need care too, with structural and boundary detail drawn properly.
The difficulty in DA15 is how quickly the rules change. A house outside a conservation area can usually rely on permitted development within the limits. Inside Halfway Street or Longlands Road, an Article 4 direction means many external changes need a full application. The Oval, The Hollies and the Willersley Avenue and Braundton Avenue pocket also tighten control locally. We check each address against these boundaries first.
Planning in Sidcup: what to know before you apply
Bexley looks for extensions that keep to the suburban building line, and in DA15 the real change comes at conservation boundaries. The Halfway Street and Longlands Road conservation areas each carry an Article 4 direction that removes permitted development for changes to elevations, roofs, windows and front boundaries visible from the street, so alterations of that kind need a planning application there. In any conservation area, including The Oval, The Hollies and the Willersley Avenue and Braundton Avenue area in Blackfen, roof enlargements, side extensions and rear extensions of more than one storey need permission anyway. Outside these areas the 1930s semis commonly keep their permitted development rights, and where an application is needed the council weighs continuity with matching neighbours. Lamorbey Park is a Grade II registered landscape on the western side of the district.
Applications are decided by London Borough of Bexley — its planning pages.
Does your Sidcup project need planning permission?
Sidcup (DA15) in numbers
What London Borough of Bexley has decided, and what DA15 is built of — the two facts that shape every job here.
Householder planning decisions — London Borough of Bexley
Sidcup (DA15) applications are decided by London Borough of Bexley; these are its published householder figures for the last four quarters.
| Householder applications decided2025 Q2 to 2026 Q1 | 939 |
|---|---|
| Granted | 895 |
| Refused | 44 |
| Grantedof 939 decisions · England 90% | 95% |
| Decided within 8 weeksof 846, excluding prior approvals | 99% |
Source: Ministry of Housing, Communities and Local Government (PS2 district planning application statistics). Open Government Licence v3.0 Extracted 2026-09-22.
Permitted development prior approvals — London Borough of Bexley
How the larger-home-extension route has fared with London Borough of Bexley, which decides DA15 notifications.
| Larger home extension prior approvals — not required2024 Q2 to 2026 Q1 | 152 |
|---|---|
| Prior approval granted | 18 |
| Prior approval refused | 30 |
| Grantedof 48 determined | 38% |
Source: Ministry of Housing, Communities and Local Government (PS1 district planning application statistics). Open Government Licence v3.0 Extracted 2026-09-22.
Planning appeals — London Borough of Bexley
Refusals in DA15 can be appealed to the Planning Inspectorate; this is London Borough of Bexley's householder appeal record.
| Householder appeals determined2021–2026 | 169 |
|---|---|
| Allowed | 59 |
| Allowedof 169 · England 36% | 35% |
Source: Planning Inspectorate appeals casework. Open Government Licence v3.0 Extracted 2026-09-22.
Conservation areas and Article 4 directions — London Borough of Bexley
Register counts for London Borough of Bexley. A count describes what the council has published, never a rank against another council.
| Conservation areas in the register22 dated, 1973–2005 | 31 |
|---|
Source: MHCLG Planning Data Platform. Open Government Licence v3.0 Extracted 2026-09-22.
What DA15 is built of
Residential building form across Sidcup (DA15), from 387 classified buildings — the fact that decides party walls, side returns and loft headroom before any policy does.
| Attached on more than one side | 42% |
|---|---|
| Attached on one side | 50% |
| Detached | 8% |
| Median building footprint | 67 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 1.04 |
| Buildings classified | 387 |
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 2026-09-22.
- Day 0Measured survey of your Sidcup property — or your existing plans if you have them.
- About 7 daysDrawings issued for your approval. Free redraws until you are happy.
- SubmissionWe validate against London Borough of Bexley’s checklist and submit on your behalf.
- Council: 8-week targetHouseholder applications carry an 8-week statutory target. London Borough of Bexley decided 99% of 846 recent householder applications inside it.
Source: Ministry of Housing, Communities and Local Government (PS2 district planning application statistics). Open Government Licence v3.0 Extracted 2026-09-22.
Streets and neighbourhoods in DA15
Nearby postcode districts
Sidcup (DA15) — FAQs
Can I do a hip-to-gable loft on my Blackfen semi?+
Can I change my windows or front wall on Longlands Road?+
Get your free Sidcup planning assessment
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