Lewisham · Catford · Forest Hill · Brockley · Hither Green · Blackheath
Dormer, L-shaped, hip-to-gable and mansard loft conversions for Lewisham's Victorian terraces and interwar semis. We check conservation area rules and handle party wall and Building Regulations.
A loft conversion in Lewisham typically costs £45,000–£80,000 for a dormer in 2026 and takes 6–14 weeks on site. Outside conservation areas most rear dormers and hip-to-gables on houses are Permitted Development. Blackheath, Brockley, Forest Hill, Hither Green and Ladywell have conservation controls.
Last updated 3 October 2026
Lewisham has more variety than most boroughs. Tight Victorian terraces fill Catford, Deptford and New Cross, Forest Hill and Lee have better-preserved period streets, and Hither Green and Brockley offer interwar semis with generous roofs. Blackheath is different again, with grand villas and strict conservation controls.
That mix means the right loft is very local. A hip-to-gable and dormer suits a Hither Green semi, a rear dormer or L-shaped dormer suits a Catford or Forest Hill terrace, and a Blackheath villa often needs a planning application and a more careful design.
Lewisham Council is generally pragmatic outside conservation areas, but Blackheath, Brockley, Forest Hill, Hither Green and Ladywell all have conservation designations, and Article 4 Directions apply in parts of them. In those areas:
Our Lewisham planning guide explains the borough rules in more depth.
On the narrow Victorian terraces of Catford, Deptford and New Cross, a rear dormer is the usual route. Plots are tight, so access, scaffolding and party wall arrangements are worth planning early.
On the interwar semis of Hither Green and Brockley, a hip-to-gable with a rear dormer typically gives the best return on space. In Forest Hill and Lee, check the conservation boundary before designing.
Indicative 2026 ranges for Lewisham houses. A free survey gives you an accurate, itemised figure for your roof.
Terraces in Catford, Forest Hill and Lee mainly suit dormers. Hither Green and Brockley semis suit hip-to-gable with a dormer. Blackheath villas usually need a planning application and a more bespoke design.
Want a personalised range first? Try our free Loft Conversion Cost Calculator.
We measure your roof void, check headroom and confirm whether your house sits in a Blackheath, Brockley, Forest Hill, Hither Green or Ladywell conservation area.
Drawings and structural calculations, then a Certificate of Lawfulness, a householder application to Lewisham Council or straight to Building Regulations.
Scaffold and skip arrangements planned for narrow streets, party wall notices served at least two months ahead, and Building Control inspections handled.
A rear dormer typically takes 6–12 weeks on site under a written JCT contract with staged payments, finishing with a snagging walkthrough.
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It depends on your address. Lewisham is generally pragmatic outside conservation areas, and most rear dormers and hip-to-gables on houses are Permitted Development within 40 m³ (terraces) or 50 m³ (semi-detached). Blackheath, Brockley, Forest Hill, Hither Green and Ladywell have conservation designations, with Article 4 Directions in parts, where you need a planning application.
Usually yes. Many interwar semis there have hipped side roofs, and a hip-to-gable with a rear dormer is often Permitted Development outside conservation areas, within the 50 m³ limit. Inside a conservation area or Article 4 area you need planning permission.
A rear dormer on a Victorian terrace in Catford, Forest Hill or Lee typically costs £45,000–£70,000 in 2026, and an L-shaped dormer £60,000–£80,000 where there is a rear outrigger. Narrow plots can complicate scaffolding and material access, which affects programme and price.
Blackheath's larger Victorian villas have bigger roofs and sit in strictly controlled conservation areas, so a planning application is usually needed and the design, materials and visibility from the street are examined closely. Budget for more design time and a cost above terrace ranges.
Narrow terraced streets in Catford, Deptford and New Cross often mean scaffolding over the pavement, which normally needs a council licence, and careful planning of skips and deliveries. Party wall notices go to adjoining owners at least two months before structural work. We handle both.
Cost figures are indicative 2026 London ranges for planning purposes, build cost only and excluding VAT, professional fees and fittings. They are not a quotation. Planning and Permitted Development rules depend on your specific address, so always confirm with your local council or a Certificate of Lawfulness.
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