An 8m x 5m One-Bedroom Garden Annexe by Swift Unlimited
Published: 15 August 2026
Reading Time: 4 minutes 50 seconds
Building an annexe for a parent asks two things of a design at once. The accommodation has to work as a proper home, and it has to sit far enough from the house that both households keep their privacy.
This 8m x 5m one-bedroom annexe by Swift Unlimited does both from the corner of a family garden. It's the second building the company have built for these owners. The first was a garden room; this time the brief was a self-contained home so the owners' mother could move in without either household losing its independence.
The 40sqm plan holds a bedroom with an en-suite shower room, and an open-plan living space with a full kitchen, a dining area and room to sit.
Test Assembled Before It Reaches the Garden
Swift Unlimited build with structural insulated panels, and every project is test assembled in factory conditions before anything arrives on site.
The photograph from the factory floor shows what that involves. The wall panels are dry assembled and numbered in the order they go back together, with the numbers marked straight onto the panels. The breather membrane goes on at the same stage, along with the battens that hold it and set the air gap between the cladding and the structure behind.
The fit is proven before the building leaves the factory, so nothing has to be solved in the garden, and the membrane means the shell is weathertight as soon as the panels are up.
For a family living a few metres away, that shortens the part of the process that's actually disruptive. The on-site phase runs to a few weeks.
A Sheltered Corner and a Three-Pane Bifold
The roof and cladding oversail one corner of the front elevation, carried on a slim anthracite post, and the recess this leaves works as a sheltered porch outside the door.
The entrance door sits back within it, glazed and 1000mm wide. The bifolds run along the adjoining face, a three-pane set 2700mm wide that folds to one side to open the living space onto the garden. Composite decked steps in a lighter grey wrap around both and step down to the lawn.
An L-Shaped Living Space and Kitchen
The building is a rectangle. The main room isn't. Taking the porch out of one corner, and a utility cupboard out of the wall beside the kitchen, leaves the living space with an L-shaped plan.
The kitchen sits in the short leg, laid out in an L of its own along two walls: an oven with an induction hob and an extractor above it, a freestanding fridge-freezer, and a run of pale grey units under a stone worktop.
A 1000mm x 500mm window sits above the sink, bringing light across the worktop from the side elevation. The rest of the room takes a dining table and a sitting area, with the bifolds overlooking the garden.
The utility cupboard beside the kitchen keeps the services out of sight: a high-level 15 litre water heater, the consumer unit, and a data point for the wifi router.
Walls and ceilings are plastered and decorated to the standard of a new build house, and the owners chose the flooring, here a pale wood-effect laminate. The electrical specification was designed with them too: socket positions, three lighting zones and the data points.
Bedroom and En-Suite Shower Room
The bedroom is 9sqm, at the far end of the plan from the kitchen. Its window is the largest in the building at 1400mm x 1000mm, and it's also the opening the room needs for escape under Building Regulations.
The en-suite is 4sqm, reached through a pocket door that slides into the wall rather than swinging into the room. Inside there's a 1200mm x 1000mm shower tray with an electric shower, a vanity unit, a WC and a heated towel rail. Walls are finished in marble-effect panels, and a small opening window offers easy ventilation.
Cedar on the Prominent Elevations
Western Red Cedar runs vertically across the elevations most visible from the house and garden. The elevations seen less, towards the boundary, are clad in anthracite grey cement particle board instead.
The roof is a single-piece EPDM membrane, and doors and windows are powder-coated aluminium in the same grey. A shallow canopy runs along the front with exterior-grade LED downlights recessed into its soffit, so the decking and the doors are lit after dark.
None of it needs much maintenance. The cedar will silver over the coming years if it's left to.
From Design Through to Handover
Swift Unlimited run the whole project as a turnkey service: the design, the approvals, the build, the connections to mains services, Building Control sign-off, and handing over the keys to a home that's ready to move into.
For these owners it was the second time through that process, and the second building from the same company. Their testimonial explains why:
Swift are an absolute first class company to work with. They are always professional, flexible and have excellent ideas. They go above and beyond at every point. Always have time to help. This is our second build and would recommend them wholeheartedly to anyone wishing to build a garden room or Annexe. We can not fault them.
Learn More
Swift Unlimited have spent nearly two decades designing and building bespoke garden rooms, annexes and extensions across mainland UK, working from a blank sheet rather than a catalogue. To find out more, visit their dedicated annexe site for living annexe projects at granny-annex.co.uk. You can contact the team on 01625 875 588 or at support@swiftunlimited.co.uk to discuss your project.
