Mansard above Georgian terrace
Camden · Grade II adjacent · 15-week build
Brief
Owners of a Georgian terrace in a Camden conservation area wanted to convert a cramped attic into a master suite. Dormers refused by Camden's conservation officer on principle; only a mansard fitted the area's planning policy.
Challenge
Grade II listed neighbour either side. Full planning permission plus conservation area consent. Welsh slate specification mandatory. Party wall agreements with two listed properties — extended surveyor process.
Solution
Pre-app meeting with Camden conservation team to agree slate spec, parapet detail, and ridge height. Welsh Penrhyn slate at 600 × 300mm. Lead rolls and code 5 flashings. Heavy steel frame to carry the new floor over the existing first-floor ceiling. Master suite plus walk-in wardrobe plus ensuite with steam shower.
Outcome
Planning + conservation consent approved at 14 weeks. Site build 15 weeks. Six-month total programme. Featured in the borough's case study material on sympathetic loft additions. Resale agent valued uplift at £310,000.
Spec
Project specification.
Gallery
Inside the build.
"Camden conservation is a maze. Builderr knew every officer by name and the application sailed through. Build quality matches the historic terrace it sits on top of."
— Helen W., Camden
Builderr vs other London builders.
The construction industry has a wide distribution of operators. Here's what changes between a directly-employed, fixed-scope outfit and the alternatives.
| Criterion | Builderr | Typical London builder | Cowboy outfit |
|---|---|---|---|
| Labour model | Directly employed team (PAYE) | Mixed subcontract gangs | Day-rate cash labour |
| Pricing | Fixed-scope itemised quote | Estimate + provisional sums | Verbal price + variations |
| Design & engineering | In-house architect + SE | Outsourced, separate billing | Builder draws on the back of an envelope |
| Planning + LDC handled | Yes — included in price | Often charged extra | Builder asks you to apply |
| Party wall surveyors | Instructed by us | Your responsibility | Skipped (illegal) |
| Building control | Plans + site inspections booked by us | Building Notice route | Not registered |
| Project management | Dedicated PM, weekly photo updates | Foreman doubles up | Owner-manager juggles 5 jobs |
| Payment schedule | Stage payments against signed-off milestones | Weekly invoices | Cash up front |
| Insurance | £10M PL + 10yr structural warranty | £2–5M PL only | No documented cover |
| Snags at handover | <3 typical | 20–30 typical | Walk-off mid-job common |
| Variation creep | 0% — fixed scope | +15–25% over original quote | +40%+ regularly |
Save £29,600–£66,600 on a mansard loft conversion.
Industry data (FMB, RICS, Which? Trusted Trader 2024) shows the average London construction project overruns by 18–22% on cost and 25–35% on time. Fixed-scope contracts with a single accountable team eliminate that variance. The savings above assume a typical project at £148,000.
Want a build like Camden?
Get a fixed-scope quote with the same direct-labour delivery. Senior consultant call within one business hour.
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