Basement extension under garden in Sidcup

Which Sidcup postcodes does this house extensions service cover?

Every Sidcup postcode district we draw in, the stock that dominates it and the authority that validates a house extensions there. Sidcup fees below are the statutory England rates for 2026, not house extensions estimates.

Which Sidcup neighbourhoods suit a house extensions best?

Roof pitch, wall build-up and plot depth change every few Sidcup streets, and each one changes what a house extensions can achieve at that address.

• Sidcup (DA14, DA15) — a house extensions in Sidcup starts from 1930s semi-detached, edwardian villas, and Sidcup reads as 1930s semi-detached, Edwardian villas. Edwardian plots here are wider in DA14. Bexley Council assesses Sidcup house extensions against its own Sidcup character guidance, and the location plan we draw for Sidcup references Sidcup station.
• Near Sidcup: Welling (DA16) — a house extensions in Welling starts from 1930s semi-detached, and Welling reads as 1930s semi-detached. 1930s semis here have the deepest rear gardens in the area in DA16. Bexley Council assesses Welling house extensions against its own Welling character guidance, and the location plan we draw for Welling references Welling High Street.
• Near Sidcup: Erith (DA8) — house extensions work in Erith means victorian terraces, post-war estates. Erith is Victorian terraces, post-war estates. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage throughout DA8. Bexley Council decides the Erith application, and Erith Riverside anchors the Erith location plan.
• Near Sidcup: Crayford (DA1) — Victorian terraces, 1930s semi-detached defines Crayford, where victorian terraces, 1930s semi-detached set what a house extensions can do. The side-return infill is the classic move on these Victorian terraces — 3 m of permitted development depth plus the width of the original side passage across DA1. Any Crayford house extensions is validated by Bexley Council, with Crayford station the usual Crayford reference point on the site plan.
• Near Sidcup: Old Bexley (DA5) — a house extensions in Old Bexley starts from georgian villas, victorian cottages, and Old Bexley reads as Georgian and Victorian village conservation. Georgian rear elevations here are usually the listed or locally listed face of the building in DA5. Bexley Council assesses Old Bexley house extensions against its own Old Bexley character guidance, and the location plan we draw for Old Bexley references Old Bexley Village.
• Near Sidcup: Belvedere (DA17) — a house extensions in Belvedere starts from 1930s semi-detached, post-war flats, and Belvedere reads as 1930s semi-detached, post-war flats. 1930s semis here have the deepest rear gardens in the area in DA17. Bexley Council assesses Belvedere house extensions against its own Belvedere character guidance, and the location plan we draw for Belvedere references Belvedere station.
• Near Sidcup: Barnehurst (DA7) — 1930s semi-detached defines Barnehurst, where 1930s semi-detached set what a house extensions can do. 1930s semis here have the deepest rear gardens in the area across DA7. Any Barnehurst house extensions is validated by Bexley Council, with Barnehurst station the usual Barnehurst reference point on the site plan.

Does Sidcup planning policy restrict a house extensions?

Conservation areas covering Sidcup: Bexley Council runs 16, and Old Bexley, Crayford, Welling are the ones Sidcup owners meet most. A house extensions inside a Sidcup conservation area loses permitted development, so the Sidcup submission is a householder application at £548 decided in 8 weeks — not a £249 prior approval decided in 6 weeks. In Bexley Village a house extensions is judged on the street elevation first.

Sidcup permitted development status: there is no borough-wide direction from Bexley Council, so a house extensions at a DA14 address is normally still permitted development. We certify that with a £274 Lawful Development Certificate rather than leaving a Sidcup sale to argue it later.

What Sidcup is built from: 1930s semi-detached dominates; Victorian cottages in Bexley Village and Crayford; post-war estates in Thamesmead and Erith. Outer south-east London suburban; very permissive planning environment; strong PD uptake for extensions and loft conversions. That mix decides the house extensions route in Sidcup more than the postcode does.

Which neighbouring authorities border Sidcup?

• Greenwich — adjoining Sidcup, with 20 conservation areas centred on SE3. A house extensions on the far side of the Sidcup line is determined by Greenwich Council, so the Sidcup quote for house extensions is checked against Greenwich guidance before it is issued.
• Bromley — adjoining Sidcup, with 48 conservation areas centred on BR1. A house extensions on the far side of the Sidcup line is determined by Bromley Council, so the Sidcup quote for house extensions is checked against Bromley guidance before it is issued.

Sources for this Sidcup house extensions page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.