House Extensions in Islington

At Bigness Group, we specialise in premium house extensions in Islington, blending the borough’s historic charm with modern design and precision craftsmanship.
From Georgian and Victorian terraces in Highbury and Canonbury to contemporary apartments near Angel and Clerkenwell, we create extensions that add light, space, and functionality while preserving the area’s unique character.

We manage every stage — design, planning, engineering, and construction — ensuring a smooth, efficient process and stunning results that last.

Design and Build Services

Our Islington design-and-build team offers a fully integrated service:

• Measured survey and bespoke architectural design

• Planning and permitted development applications for Islington Council

• Structural calculations and Building Control liaison

• Interior planning, kitchen design, and lighting solutions

• Dedicated project management and milestone tracking

With one expert team overseeing the entire project, you get accountability, clear communication, and the signature Bigness quality guarantee.

Types of Extensions We Build

We construct all major types of home extensions across Islington, including:

• Glass Box Extensions – Contemporary architectural additions.
• Modern House Extensions – Sleek designs that fuse architecture and innovation.
• Single-Storey Extensions – Expand your kitchen, dining, or family area with natural light.
• Double-Storey Extensions – Add bedrooms or offices above while extending living space below.
• Side-Return Extensions – Perfect for semi-detached and terraced homes.
• Rear Extensions – Create spacious, modern garden-facing living areas.
• Wrap-Around Extensions – Combine side and rear builds for full open-plan layouts.
• Conservatories & Orangeries – Glazed extensions for all-season comfort.
• Loft & Garage Conversions with Extensions – Add new rooms vertically or repurpose existing structures.

Construction Standards

Every Bigness project in Islington follows a strict six-step build process:

1. Groundworks & Foundations – Tailored for tight urban sites and heritage zones.

2. Structural Steelwork – RSJs and beams installed for open-plan strength.

3. Walls & Roofs – Brick match or render finishes with warm-roof insulation.

4. Windows & Glazing – High-performance, Part L–compliant glazing systems.

5. Interior Finishes – Plumbing, electrics, flooring, and bespoke joinery.

6. Final Inspection & Certification – Building Control approval and warranty.

Local Knowledge

We have extensive experience working with Islington Council’s planning policies, including conservation areas such as Highbury Fields, Barnsbury, and Canonbury.
Our designs are tailored to meet local character guidelines while introducing modern engineering and energy efficiency — ensuring smooth approvals and lasting beauty.

Costs and Financing

Every extension is unique, but here’s a general guide:

💡 Factors include size, materials, access, and specification level.

We provide transparent quotes with detailed breakdowns and stage payments.
Financing options may be available through our partner lenders for eligible clients — ask our team for guidance on home improvement financing.