Award-Winning Design & Build for Islington’s Period Properties
Islington is defined by its Georgian terraces. Streets like Canonbury Square, Barnsbury, Cloudesley Road, and Thornhill Square contain some of London’s finest early 19th-century residential architecture. The borough also has extensive Victorian streets, particularly around Highbury, Holloway, and Upper Street. These properties are beautiful, characterful, and often in conservation areas — which means extending or converting them requires architectural sensitivity and planning expertise.
LCCL Construction is an LABC Award-winning design and build company that specialises in period property alterations across North London. Our in-house team — architects, structural engineers, project managers, and builders — delivers house extensions, loft conversions, renovations, and architectural services under one contract and one comprehensive quote. No separate architect to hire. No subcontractors. One company accountable for everything.
Our office is in Finchley N3, about 20 minutes from most Islington addresses.
Why Islington Homeowners Choose LCCL
LABC Building Excellence Award Winners 2024 — The UK’s highest independent recognition of construction quality, judged by building control professionals.
200+ Reviews Averaging 4.7/5 — Consistent quality across hundreds of projects, verified by real homeowners.
Georgian & Victorian Specialists — Extensive experience with period properties, conservation areas, and the specific challenges of terraced house construction.
Complete Design & Build — Architecture, engineering, planning, construction, project management, and 10-year LABC warranty. One quote covers everything.
Our Services
Design and build under one roof, Architecture, planning, construction, and finishing — managed by one team, from start to finish.
- HOUSE EXTENSIONS
House Extensions in Islington
Islington’s terraced properties present a specific extension challenge: narrow frontages, party walls on both sides, and limited rear garden depth. The most effective strategies are rear extensions that maximise the ground-floor footprint and side return infills that absorb wasted alley space. Because much of Islington is within conservation areas, most extensions require planning permission from Islington Council.
Extension Types for Islington Properties
Rear Extensions — The most popular project in Islington. A single-storey rear extension with a roof lantern or skylight creates a contemporary kitchen-dining space. Within conservation areas, planning permission is typically required. Costs: £55,000 to £95,000.
Side Return Extensions — Many Victorian terraces have a narrow side passage. Enclosing this and opening up the side wall transforms a cramped galley kitchen into a generous open-plan space. Often combined with a rear extension. Costs: £45,000 to £65,000.
Basement Extensions — With Islington property values regularly exceeding £1 million, basements are increasingly popular. Many Georgian properties already have lower ground floors that can be improved. Costs: £150,000 to £400,000+.
Double-Storey Rear Extensions — More achievable on end-of-terrace and semi-detached properties. Costs: £110,000 to £200,000+.
What Is Included in Every Extension Quote
All prices include: in-house architectural design, structural engineering, planning applications to Islington Council, all construction labour and materials, project management, building control via LABC, and a 10-year LABC warranty. All-inclusive — no hidden extras. Call 020 8037 7332.
- LOFT CONVERSIONS
Loft Conversions in Islington — Period Terraces, Modern Living
Islington’s Georgian and Victorian terraces typically have steeply pitched roofs with good ridge heights, creating excellent loft conversion potential. A well-designed conversion adds a full bedroom with en-suite at the top of the house. The value uplift in Islington, where the average terraced house price exceeds £1 million, makes loft conversions one of the best investments a homeowner can make.
Planning requirements depend on location. Outside conservation areas, most rear dormer conversions qualify under permitted development. Within Islington’s many conservation areas, planning permission is required, and design must demonstrate sensitivity to the roofscape.
Loft Conversion Types for Islington Properties
Rear Dormer Conversions — The most popular type across Islington. A flat-roofed rear dormer maximises headroom and floor area while preserving the front roofline. Costs: £50,000 to £75,000.
Mansard Conversions — The premium option creating near-full-height rooms on both sides. Requires planning permission and careful design, particularly in conservation areas. Costs: £70,000 to £100,000+.
L-Shaped Dormers — For end-of-terrace properties where both rear and side dormers are achievable. Creates space for two bedrooms or a large master suite. Costs: £65,000 to £90,000.
Rooflight-Only Conversions — For listed buildings or the most sensitive conservation area locations. Costs: £40,000 to £58,000.
What Is Included in Every Loft Conversion Quote
All prices include: in-house architectural design, structural engineering, planning applications to Islington Council, scaffolding, all construction, staircase, insulation, electrics, en-suite plumbing, building control via LABC, project management, and a 10-year LABC warranty. No hidden extras. Call 020 8037 7332.
- RENOVATIONS
Renovations in Islington — Georgian Sensitivity, Modern Standards
Islington’s Georgian terraces were designed for a very different way of living. Separate parlours, below-stairs kitchens, narrow hallways, and small rear rooms don’t suit modern family life. A well-planned renovation can reconfigure these beautiful properties for contemporary living while preserving — or restoring — their original character.
Full renovations often include structural reconfiguration of the ground floor to create open-plan kitchen-dining spaces, restoration of period features including cornicing, shutters, fireplaces, and panelled doors, complete kitchen and bathroom installations, rewiring and replumbing, new heating systems, and insulation improvements compatible with solid-wall construction.
For listed buildings, internal renovation work may require Listed Building Consent. Our architects manage all applications. Typical renovation costs in Islington: kitchen renovation £30,000 to £65,000, bathroom renovation £14,000 to £30,000, structural wall removal with steelwork £6,000 to £15,000, whole-house refurbishment from £100,000 upward.
- ARCHITECTURE
In-House Architecture — Islington Conservation Area Specialists
Islington has over 40 conservation areas covering large parts of the borough. Barnsbury, Canonbury, Duncan Terrace, Cloudesley, Highbury Fields, and many more — each with its own character appraisal and specific design sensitivities. Navigating this planning landscape requires architects who understand Islington Council’s conservation and planning teams.
LCCL’s in-house architects submit applications to Islington Council and understand the borough’s design policies for period properties. The integrated design and build model means designs are always buildable and accurately costed from day one.
Every Islington project includes: measured survey, concept designs, 3D visualisations, construction drawings, planning applications to Islington Council, design and access statements, structural engineering, and building regulations via LABC. All included in your quote — no separate architect fees.
- LOCA PLANNING EXPERTISE
Planning & Local Knowledge — Islington
Planning Authority
Islington properties fall within the London Borough of Islington. All planning applications for N1, N5, N7, and EC1 addresses within the borough are submitted to Islington Council’s planning department.
Conservation Areas
Islington has over 30 designated conservation areas. Major ones include: Barnsbury Conservation Area — One of London’s finest collections of Georgian terraces, with Article 4 Directions restricting PD rights. Canonbury Conservation Area — Georgian and early Victorian streets with strict design controls. Duncan Terrace and Colebrooke Row — Elegant Georgian terraces along the New River. Highbury Fields Conservation Area — Victorian and Edwardian properties. Cross Street Conservation Area — Around Upper Street and Essex Road.
Permitted Development Rights
Outside conservation areas, standard permitted development rights apply. Within conservation areas — which cover much of desirable Islington — rights are significantly restricted. Most rear dormers, extensions visible from public viewpoints, and any front-facing alterations require planning permission. Lawful Development Certificates are recommended where PD applies.
Typical Planning Timescales
Householder planning application: 8-week target decision. Lawful Development Certificate: approximately 8 weeks. Pre-application advice: available and recommended for conservation area proposals. Building control: inspections throughout, final sign-off at completion.
Party Walls
Almost all Islington extensions involve party walls shared with neighbouring properties. The Party Wall etc. Act 1996 requires formal notification before work begins. We manage party wall notices as part of the project.
Building Control
All LCCL projects are managed through LABC building control. Inspections at each key stage ensure compliance with Building Regulations. At completion, you receive a building control completion certificate and optional 10-year LABC warranty.
Frequently Asked Questions
Do I need planning permission for an extension in Islington?
If your property is in one of Islington’s 40+ conservation areas, most external alterations require planning permission. Outside conservation areas, some extensions qualify under permitted development. Our architects assess your property and handle all applications.
How much does an extension cost in Islington?
Rear extensions: £55,000 to £95,000. Side return extensions: £45,000 to £65,000. Double-storey: £110,000 to £200,000+. Basement extensions: £150,000 to £400,000+. All prices include architecture, engineering, planning, construction, and 10-year LABC warranty.
What type of loft conversion suits Islington terraces?
Georgian and Victorian terraces typically suit rear dormer conversions (£50,000 to £75,000) or mansard conversions (£70,000 to £100,000+). Within conservation areas, planning permission is required. Our architects design proposals that satisfy Islington’s conservation team.
Can I extend a Georgian property in a conservation area?
Yes. Well-designed extensions in Islington’s conservation areas are regularly approved. The key is architectural sensitivity — using appropriate materials, proportions, and detailing that complement the existing building. Our architects have specific experience with Georgian properties.
How long does a project take?
Loft conversions: 8 to 12 weeks on site. Extensions: 10 to 20 weeks depending on scale. Allow 8 to 12 weeks for design and planning approvals before construction starts. We provide a detailed timeline with every quote.
Areas We Cover
Based in Finchley N3, serving London and Hertfordshire.
North London and Hertfordshire
Barnet | Finchley | Hendon | Muswell Hill | Edgware | Enfield | Borehamwood | Potters Bar | Watford | St Albans
Across London
Hampstead | St Johns Wood | Islington | Kensington & Chelsea | Fulham | Clapham | Richmond | Putney & Wandsworth | Crouch End | Stoke Newington | Highgate | Ealing | Notting Hill | Camden | Queens Park