Dormer, hip-to-gable, mansard, and L-shape loft conversions across Barnet and North London—adding luxury living space.
Turn unused roof space into a valuable extra bedroom, en-suite or family living area with a fully managed loft conversion from The Construction Collective. We are loft conversion specialists in Barnet and across North London, delivering structurally sound, beautifully finished conversions that add real value to your home.
Get an instant cost estimate for your extension, loft conversion, renovation or new build — tailored to your project in under 60 seconds.
We work on every loft conversion type common to Barnet and North London homes — dormer conversions for terraced and semi-detached properties, hip-to-gable for end-of-terrace and detached homes, mansard conversions for period properties and L-shape conversions for Victorian and Edwardian terraces.
Structural calculations, party-wall agreements, planning or permitted development applications and building control inspections are all coordinated for you. You get one accountable team, a single point of contact and a tidy site every evening.
We cover Barnet, Finchley, Hampstead, Mill Hill, Whetstone, Totteridge, Hendon, Edgware, Radlett, Potters Bar and St Albans.
We build all types of loft conversion including dormer, hip-to-gable, L-shaped, mansard and Velux/roof light conversions. Each type suits different property types and budgets — visit our dedicated loft conversion sub-pages or contact us for advice on which type suits your home.
Most loft conversions in Barnet fall under Permitted Development rights and don't require planning permission, provided they meet national size and design criteria. Properties in conservation areas or those wanting a mansard conversion will need full planning permission. We assess this for every client as part of our free site visit.
Costs range from approximately £25,000 for a basic Velux conversion to £90,000+ for a full mansard. A typical dormer loft conversion in Barnet costs £45,000–£65,000. Use our Online Price Guide for an instant estimate.
A typical dormer loft conversion takes 10–14 weeks from start to finish. More complex conversions such as mansard or L-shaped may take 14–20 weeks. We provide a detailed programme at quotation stage.
Yes — in most cases you can remain at home throughout. The main period of disruption is during structural work and staircase installation, which typically lasts 2–3 weeks.
Yes — significantly. A well-executed loft conversion in North London typically adds 15–25% to the value of your property. In Barnet, Hampstead and Mill Hill this can represent £100,000–£250,000 or more in added value.
Yes — we prepare and submit all building regulations drawings and manage all inspections on your behalf. This is included in our fully managed service.
As a general rule, you need a minimum of 2.2 metres from the floor joists to the ridge of the roof for a viable loft conversion. If you're unsure, our team can assess this during a free site visit.
A complex Category 3 dormer loft conversion creating a high-spec upper-floor residential dwelling above active commercial high-street premises in Friern Barnet (N11). Features bespoke timber winder staircase access, acoustic floor decoupling, and full Building Control Part B fire separation.
A loft conversion on an existing bungalow, creating a new master bedroom and designer en-suite.
Get an instant cost estimate for your extension, loft conversion, renovation or new build — tailored to your project in under 60 seconds.
We work throughout North London and Hertfordshire. Choose your area for local guidance, planning insight and recent projects near you.
Book a free, no-obligation consultation. We'll visit your home, listen to your brief and tell you honestly what's possible.
Or message us directly on WhatsApp — we typically respond within the hour.
