Single-Storey Extensions in London

At Bigness Group, we specialise in single-storey house extensions that unlock space, light, and value — from bright kitchen/diner additions to seamless open-plan living. We handle every stage of your project: design, permissions, construction, and finishing.

Whether you’re planning a rear, side-return, or wrap-around ground-floor extension, our design-and-build team delivers precision workmanship and a smooth, well-managed project from concept to completion.

Design and Build

Our integrated design-and-build approach means one dedicated team manages your entire extension — from first sketch to final inspection.

• Measured survey, concept design, and 3D visuals (on request)

• Planning or permitted development advice and submissions

• Structural engineer’s calculations and Building Control liaison

• Interior design, kitchen layout, lighting, and finish selection

• Dedicated project manager ensuring transparency and quality

This single-team structure keeps communication clear, timelines tight, and craftsmanship consistent.

Types of Single-Storey Extensions

We design and construct every major type of single-storey extension, including:

• Rear extensions – Open your home to the garden with large glazed doors and skylights.

• Side-return extensions – Ideal for Victorian and Edwardian homes to widen narrow kitchens.

• Wrap-around extensions – Combine rear and side expansion for a full layout transformation.

• Kitchen extensions – Create a contemporary cooking and dining hub with natural light and flow.

• Orangeries and contemporary glazed designs – Elegant glass structures for year-round use.

Construction

Every Bigness project follows a clear, structured process:

1. Groundworks & Foundations – Surveys, excavation, and structural preparation.

2. Steel & Framework – Installation of RSJs, lintels, and load-bearing supports.

3. Roof & Waterproofing – Flat warm roofs (EPDM or GRP) or lightweight pitched systems.

4. Glazing & Openings – Slimline aluminium bifolds or sliders with energy-efficient glass.

5. First & Second Fix – Electrical, plumbing, plastering, carpentry, and finishing.

6. Sign-off & Handover – Building Control approval and warranties provided.

All works meet UK Building Regulations and current energy-efficiency standards.

Materials

We help you select the best materials for performance, durability, and style:

• Structure: Steel frames, engineered timber, or masonry systems.

• Exterior: Brick match, render, or modern cladding options.

• Roofing: Warm-deck flat roofs, GRP or EPDM membranes, or tiled pitched roofs.

• Glazing: Thermally broken aluminium with low-U-value double or triple glazing.

• Interiors: Bespoke joinery, LED lighting, and premium flooring finishes.

All materials are sourced from trusted, sustainable suppliers.