Builders in Finchley N3 & N12 | House Extensions & Conversions
Trusted local builders delivering high-end residential building services across Finchley (N3 / N12) and surrounding North London & Hertfordshire postcodes.
Direct line to our Barnet project team • Mon–Fri 8:00am – 5:00pm
High-end residential building services in Finchley.
The Construction Collective has delivered premium building projects across Finchley's N3 and N12 postcodes, working on everything from Victorian rear extensions to full-property refurbishments. Finchley's diverse housing stock — from Edwardian terraces in East Finchley to 1960s properties in North Finchley — requires builders who understand the local character and planning environment. That's exactly what we bring.
Whether you're planning a kitchen extension, loft conversion or complete renovation in Finchley, our fully managed service handles every stage — from planning permission through to final handover.
Recent Projects in North London
While we prepare a dedicated Finchley case study, explore current structural, extension and conversion work delivered by our team across North London.
Single-Storey Rear Extension & Structural Renovation
A turnkey single-storey rear extension and full ground floor reconfiguration in East Barnet (EN4), featuring extensive structural steel knock-throughs, precision subfloor screeding, and complete architectural fit-out.
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Category 3 Dormer Loft Conversion Above Commercial Premises
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.
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Full Property Renovation
Full ground-floor property renovation in the Hampstead conservation area — sympathetic restoration with a contemporary finish.
View projectLocal Planning & Building Control in Finchley
London Borough of Barnet
Projects in Finchley should be checked against the London Borough of Barnet's current planning guidance before design work is finalised. Many single-storey rear extensions and loft conversions can proceed under Permitted Development, but those rights have size and design limits and can be removed or restricted in conservation areas, by Article 4 directions or on flats and listed buildings. Finchley's Edwardian terraces and inter-war semis often suit rear and side extensions and loft conversions, while properties in conservation areas need extra care over roof alterations and street-facing changes.
Building Control approval is separate from planning and covers structure, fire safety, insulation, ventilation and drainage. Where work involves a shared wall, a new steel bearing into a party wall or excavation close to neighbouring foundations, the Party Wall etc. Act 1996 usually applies and notices must be served before work starts. We coordinate the architect, structural engineer, party wall surveyor and building inspector so these approvals are in place before construction begins.
Governing Council
Planning applications, prior approvals and Lawful Development Certificates for Finchley (N3 / N12) are decided by the London Borough of Barnet. We check its current local plan and design guidance before drawings are finalised.
Permitted Development Realities
Loft conversions can typically add up to 40m³ of roof space on terraced houses and 50m³ on semi-detached and detached houses. Single-storey rear extensions can usually project 3m (attached) or 4m (detached) under standard rights, extending to 6m or 8m through the prior approval process. Flats, maisonettes, front or side-facing dormers and anything beyond these limits need full planning permission.
Conservation Areas & Article 4
Conservation areas, listed buildings and Article 4 directions remove or restrict Permitted Development rights. Where they apply we prepare the correct planning or listed building consent route, with materials and detailing matched to the street's character.
Permitted Development limits are summarised from national rules; every property is confirmed at survey.
Typical Project Timelines in Finchley
Rear & Kitchen Extensions
10–14 Weeks
Fixed-price structural shell to turnkey finish.
Dormer & Mansard Lofts
7–10 Weeks
Complete structural timberwork, glazing & Part P/B sign-off.
Full Home Refurbishments
8–16 Weeks
Structural reconfiguration, acoustic decoupling & bespoke joinery.
Typical on-site durations once approvals are in place; your exact programme is set out with your quotation.
Managed Site Operations Across Finchley
- Council highway permits, scaffolding licences and parking bay suspensions fully managed.
- Timed muck-away grab collections to prevent street congestion.
- Full adherence to the Party Wall etc. Act 1996 on all shared structural boundaries.
Five clear steps. Zero surprises.
Free Site Visit & Consultation
We visit your property, discuss your ideas and provide practical advice on the best way to achieve your goals.
Design & Planning
We work with architects and consultants to prepare drawings, planning applications and technical information where required.
Quotation & Programme
A detailed quotation outlining the scope of works, project timeline and key milestones — so you know exactly what you're paying for.
Construction
Your dedicated project manager oversees every stage of the build, coordinating trades and maintaining quality standards.
Completion & Handover
Final inspections are completed and your project is handed over ready for you and your family to enjoy.
How much will your project cost?
Get an instant cost estimate for your extension, loft conversion, renovation or new build — tailored to your project in under 60 seconds.
Frequently Asked Questions
Common questions from homeowners in Finchley (N3 / N12).