Loft conversions in Sidcup
Loft conversion specialists based in Sidcup. Hip-to-gable and dormer conversions on the 1930s semis of Blackfen, Lamorbey and Albany Park, and sensitive work within the Sidcup conservation areas.
Hipped roofs made for conversion
Sidcup was built out largely between the wars, and its housing stock is dominated by three-bedroom semis with the hipped roofs that make hip-to-gable loft conversions both straightforward and highly effective. Add a rear dormer and most of these houses gain a full double bedroom and en-suite without touching the footprint.
Kelmend Construction is based in Sidcup, and our loft conversions service covers the whole of DA14 and DA15. We know the roof structures typical to each estate and which of the eight Sidcup conservation areas restrict roof alterations.
We know your roof
1930s hipped semis
The dominant house type: interwar semis with generous hipped roofs and cut roof structures throughout. Almost universally suitable for hip-to-gable conversion, and good ridge heights mean a Velux conversion is often feasible too.
Edwardian houses
Steeper roof pitches and good ridge heights suit rear dormer and mansard conversions. Several of these streets are in conservation areas, so dormers need planning permission and careful design.
The Hollies and Longlands
Cottage-style interwar houses with distinctive roofs. Conversions are possible but must be subordinate to the original roof line and invisible from the street. We've designed within these constraints before.
Larger detached and semis
Bigger roof volumes that can often take two bedrooms and a bathroom in one project. The Green is a conservation area.
Post-war housing
Post-war houses often have trussed roofs that need structural alteration before conversion. We assess the roof structure at the consultation so the quote reflects what's actually there.
Interwar and post-war
Mixed stock toward New Eltham and Avery Hill, mostly outside conservation areas, with straightforward permitted development scope.
Types of loft conversion we build in Sidcup
Hip-to-gable
Extends the sloping hip end of the roof to a vertical gable, the most effective single alteration on a 1930s semi. Usually permitted development outside conservation areas, and most often combined with a rear dormer.
Hip-to-gable and rear dormer
The combination that delivers the most usable space on Sidcup's semis: a large bedroom, en-suite and often a second room. Usually permitted development.
Rear dormer
A box dormer projecting from the rear roof slope. Effective across Sidcup's Edwardian and 1930s houses alike, and permitted development outside conservation areas.
Velux / rooflight
No change to the roof shape. On Sidcup's semis with generous pitches, a Velux conversion is often feasible and the most affordable way to add a bedroom. Almost always permitted development.
Mansard
Changes the rear roof slope to near vertical for maximum headroom. Always requires planning permission. Suits the older terraces near the station where the existing pitch limits head height.
L-shaped dormer
Combines a rear dormer with a side dormer over an existing rear addition. Suits the larger houses around Lamorbey Park. Requires planning permission in most cases.
What you need to know before converting a loft in Sidcup
Sidcup sits in the London Borough of Bexley. Most loft conversions here are permitted development, but Sidcup's eight conservation areas change the rules street by street.
Permitted development
Most Velux, rear dormer and hip-to-gable conversions on Bexley's 1930s semis fall under permitted development outside conservation areas. Volume limits apply: 40m³ for terraced houses and 50m³ for semi-detached and detached. We verify this for your property first.
Conservation areas
Bexley has 23 conservation areas, including eight in Sidcup, Old Bexley, Parkhurst and Red House Lane. Dormers visible from the street in these areas need planning permission, and front dormers are rarely approved.
Article 4 directions
Old Bexley, Old Forge Way, Red House Lane and Brook Street carry Article 4(2) directions removing some permitted development rights, so even modest roof alterations need a full application there.
Interwar character
Bexley's design guidance expects dormers to sit below the ridge, set back from the eaves and clad in materials matching the existing roof. Designing to that from the start avoids refusals.
Building regulations
All loft conversions need building regulations approval covering structure, fire safety, insulation and the staircase. Bexley building control inspects at key stages and we manage the whole process.
Party walls
Hip-to-gable and dormer conversions on semi-detached houses almost always involve the shared wall. We flag this early so notices are served and agreements reached before work starts.
Sidcup's conservation areas
Eight conservation areas cover parts of Sidcup. Dormers visible from the street in these areas need planning permission:
Old Forge Way also carries an Article 4 direction. We check your address against Bexley's current maps at the consultation.
Why Sidcup homeowners choose us
Based in Sidcup
We're based in Sidcup, so your roof assessment, your build and any snag afterwards are minutes away.
Hip-to-gable specialists
The hip-to-gable conversion was made for Bexley's 1930s hipped-roof semis. We've delivered it many times and know how to get the most floor area out of the roof.
Bexley Council experience
We know what Bexley's planning team expects of dormers in its conservation areas and what falls cleanly under permitted development elsewhere.
Directly accountable
You deal with us throughout. On a semi-detached street where the neighbours are a wall away, that matters.
Itemised, honest quotes
Fully itemised quotes with no hidden costs. Any changes mid-project are costed in writing first.
Full project management
Structural engineer, building control and any planning application are all managed by us.
Our loft conversion process in Sidcup
Free consultation and roof assessment
We visit your property, go into the loft and assess the roof structure, head height and planning position, including conservation area status for your address. We tell you what's feasible, what it will cost and whether planning permission is required before any design work begins.
Design and planning
We work with your architect, or recommend one familiar with Bexley Council. We advise on the planning route and manage the process, including party wall notices.
Detailed quote and contract
Once drawings are finalised we produce a fully itemised quote covering every element of the project. Scope, programme, stage payments and how variations are handled are set out in writing before any work begins.
The build
Structural work, roof alteration, insulation, windows and rooflights, first fix, plastering, second fix and decoration are managed as one programme, with regular updates throughout. The site is kept clean and secure every day.
Staircase and fit-out
The staircase is designed and built to fit the property properly, not squeezed in as an afterthought. Fit-out includes flooring, a bathroom if included, and all finishing trades coordinated without gaps between them.
Building control sign-off
Bexley Council building control sign-off is obtained and we walk the finished loft with you to pick up any snags. The completion certificate is yours to keep. We don't close the job until you're satisfied.
Covering Sidcup and the borough
Based in Sidcup and converting lofts across the London Borough of Bexley, including:
Sidcup loft conversion FAQs
How much does a loft conversion cost in Sidcup?
A Velux conversion typically costs £20,000 to £35,000. A rear dormer runs £35,000 to £60,000. A hip-to-gable with rear dormer typically costs £45,000 to £70,000. A mansard on a Victorian or Edwardian terrace runs £55,000 to £80,000 and upwards. All figures are fully finished. We'll give you an accurate figure after visiting your property and assessing the roof structure.
Do I need planning permission for a loft conversion in Sidcup?
Most conversions on 1930s semis fall under permitted development outside conservation areas. Mansards always need planning. Properties in the local conservation areas or Article 4 areas need permission for most roof alterations. We check the position for your address at the consultation.
Is my 1930s semi suitable for a hip-to-gable conversion?
Almost certainly. The borough's interwar semis have generous hipped roofs and cut roof structures that make hip-to-gable conversions both structurally straightforward and highly effective. The key checks are ridge height, ideally 2.2m or more, and whether the property is in a conservation area. We assess both at the free consultation.
How long does a loft conversion take in Sidcup?
A Velux conversion takes 4 to 6 weeks on site. A rear dormer or hip-to-gable takes 8 to 12 weeks. A combined hip-to-gable and rear dormer takes 10 to 14 weeks. A mansard takes 12 to 16 weeks. Planning permission, where required, adds 8 to 13 weeks before work can begin. We'll give you a realistic programme in your quote and stick to it.
Will a loft conversion add value to my Sidcup home?
In most cases, significantly. Adding a bedroom with en-suite moves a three-bedroom semi into a different price bracket, and a well-executed conversion typically adds 10 to 20% to value.
Can I stay in my home during the loft conversion?
Yes. Loft conversions are among the least disruptive projects because most of the work happens above the existing living space. The main disruption is the staircase installation, which we plan carefully. Most clients stay at home throughout.
Converting your loft in Sidcup?
We're based here. Tell us about your project and we'll come round for a free, no-obligation roof assessment.
No pushy sales. No call centres. Just a straight conversation about your Sidcup project.