Rear extensions
Open up the back of the house for larger kitchens, dining rooms, family spaces and a stronger connection to the garden.
↗HOUSE EXTENSIONS · SOUTH LONDON & SURREY
More space should make the whole house work better.
Rear, side, wraparound and two-storey extensions planned around how you want to live — with the structure, glazing, services and existing house coordinated as one project.
01 The new space has to work with the house you already have.
THE REAL BRIEF
An extension is not just extra square metres.
A good extension changes how the existing house works. Circulation, daylight, views, storage, kitchen layout, heating, structure and the relationship with the garden all need to be considered together.
That is why we treat the extension and the existing home as one project rather than concentrating only on the new footprint.
WAYS TO ADD SPACE
The form follows the property.
Side & side-return extensions
Use under-performing side space to widen the plan, improve circulation or unlock a better kitchen and utility arrangement.
↗Wraparound extensions
Combine rear and side expansion where the property allows it, creating a much more substantial ground-floor reconfiguration.
↗Two-storey extensions
Add upper-floor space as well as ground-floor area, with the structure, roof and existing elevations considered as one composition.
↗FROM FOOTPRINT TO FINISHED ROOM
The extension only works when the stages connect.
A real Harrington Builders sequence from Hillside — not a generic stock construction story.
WHAT HAS TO WORK TOGETHER
One extension. Six connected systems.
Structure
Openings, steelwork, bearings, foundations and how the new construction ties back into the existing house.
Envelope
Roof, insulation, masonry, waterproofing, glazing and the details that make the new space comfortable and durable.
Light & views
Rooflights, doors, windows and internal openings positioned around how the room will actually be used.
Services
Heating, underfloor heating, electrics, lighting, data and plumbing planned before finishes close the work in.
Existing house
Floor levels, ceilings, finishes and circulation resolved so the extension feels integrated rather than attached.
Garden & exterior
Thresholds, patios, drainage and the relationship between the new rear elevation and the outside space.
DESIGN DECISIONS THAT CHANGE THE BUILD
Some choices affect far more than appearance.
01Large openings
Structural design, temporary works and installation sequence.
02Glazing
Lead times, structure, thermal performance and thresholds.
03Floor build-up
Existing levels, insulation, UFH and finished-floor continuity.
04Kitchen position
Drainage, ventilation, electrics, lighting and circulation.
HOW HARRINGTON BUILDERS RUNS THE JOB
Four control points, not another seven-step timeline.
Define
Drawings, structural information, specification and existing conditions are developed far enough to price and plan the work properly.
Prepare
Programme, access, long-lead items, temporary works, site setup and key selections are coordinated before they become site delays.
Build
Structure, envelope, services and fit-out are managed as one sequence, with Stuart remaining directly involved throughout.
Integrate
Making good, finishes, testing and handover focus on leaving the extension feeling like part of the home, not a separate add-on.
START WITH THE PROPERTY
Planning an extension?
If you already have drawings, send them over. If you are earlier in the process, tell us what you want the house to do differently and we can discuss what information is needed next.
Start your project