Carisbrooke Road – Two-Storey Side Extension

Project Scope and Construction

At Carisbrooke Road in Cambridge we built a two-storey side extension and remodelled the inside of the house to go with it, adding space on both floors and tying the new structure into the roof, windows, drainage, services and finishes as one job.

The gallery mixes finished details, the new front elevation, the pitched roof, a new room and bathroom, with photographs from the build: the timber structure, the brickwork and the scaffolding that formed the extension.

Groundworks and structural construction

After the enabling and demolition work we put in new foundations and the ground floor. The extension is facing brickwork and insulated blockwork with a timber first floor, joined to the existing house through new structural openings. The bricks were chosen to sit well against the original house, and part of the elevation is finished in external cladding.

This combination of masonry, insulation and structural carpentry is typical of a substantial two-storey house extension. Each stage depends on the approved drawings and structural information, from the foundation design and load paths through to wall, floor and roof junctions.

Roof, glazing and external envelope

A new pitched tiled roof covers the extension, with rooflights, new uPVC windows and external doors including an aluminium glazed door set. Getting the roof and glazing finished made the new rooms weathertight before plastering and the final fix.

The finished external photographs show how facing brickwork and blockwork, light-coloured cladding and the roof form bring the side extension together with the original house.

Internal alterations and services

Inside we built new partitions, boarded and skimmed, hung internal doors and joinery, tiled walls and floors and decorated. The services work covered electrics and lighting, heating and plumbing, including the connections for a utility area and a new bathroom, plus the below-ground drainage and rainwater connections.

This is why a project of this scale needs more than an external shell. Structural work, internal alterations, mechanical and electrical services, plastering, tiling and decorating have to be sequenced so that finished areas are not disrupted by later trades.

Planning a similar extension

The final programme for this job had the finishing work, structural completion, plastering, cladding, windows and doors, tiling, final-fix services, joinery and decorating, completed in November 2025. Those dates belong to this project; they are not a standard duration for every extension.

For another property, the programme depends on access, drawings, approvals, structural design and the level of internal fit-out. Our builder’s quotation guide and Cambridge extension cost guide explain how that scope is priced and compared. See more building projects in Cambridge and Cambridgeshire, or request a quote to discuss your plans.