A garden gym, office & sauna studio in Kent
Two black-clad buildings in a Kent garden, linked by a composite deck: an 8m × 4m gym and office, and a 3m × 2.5m sauna studio.
Set in a large garden in the Kent countryside, this project by Ark Design Build showcases what can be achieved when working with a bespoke garden room designer. The client wanted a multifunctional setup that included space for a home gym, a separate office, and a dedicated sauna room. Ark’s solution: two beautifully detailed garden rooms, connected by a generous composite deck, which together create a striking and highly practical addition to the home.
At a glance
- Size: An 8m × 4m gym and office, plus a 3m × 2.5m sauna studio.
- Built for: Training, working and a sauna, each in its own space.
- Construction: Multi-layer insulated timber frames under Permitted Development, with an asymmetric pitched roof and a 3m vaulted ceiling.
- Finishes: Black Thermowood with a natural Thermowood recess around the doors; plastered walls and Philips Hue lighting inside.
- Company: Ark Design Build, who prepared the sauna building for its chimney flue.
Built under Permitted Development
This project was built under the Permitted Development rules, as the buildings sit more than 2 metres from the garden boundaries. These rules allow for a dual-pitched roof design with a maximum height of 2.5 metres at the eaves and up to 4 metres at the ridge. The client opted for an asymmetrical roofline, where the ridge is placed off-centre-a purely aesthetic choice rather than a tactic to reduce the ridge height (as we’ve seen in some other garden room designs). This decision gives the building a more dynamic form and, when combined with the precise detailing of the cladding, adds a real architectural edge.
Two garden rooms, one cohesive design
Rather than one large building, Ark Design Build created two distinct garden rooms, connected by a wide composite deck that offers a seamless link between the two spaces.
The larger of the two buildings measures 8m x 4m and is divided into two rooms. The main area is a home gym, complete with bi-fold doors, air conditioning, and a vaulted ceiling that peaks at 3 metres-making it feel light and spacious, even when in full workout mode. Separated from the gym by an internal wall, there’s a smaller home office, with its own separate entrance on the side elevation.
Inside the office, Ark has included a large picture window positioned at desk height, offering both natural light and views across the garden. The room has been finished with plastered and decorated walls and ceiling, and the vaulted ceiling makes the compact footprint feel anything but cramped. Lighting is carefully considered too, with a Philips Hue lighting system combined with up and down wall lights, allowing the owner to tailor the ambience depending on the task at hand.
Multi-layer structure and striking cladding
Ark Design Build’s buildings are based on a multi-layer insulated timber framework, designed for comfortable year-round use.
Externally, the cladding is a key design feature. Black Thermowood boards have been fixed vertically, giving a sleek and contemporary feel. Around the bi-fold doors, Ark created a recessed section of natural Thermowood, fixed horizontally, which offers a welcome contrast. This detail not only adds visual relief but also frames the entrance beautifully. The use of colour-matched black recessed downlights here is particularly effective-they’ll cast a warm glow over the timber in the evening and illuminate the entryway.
A sauna studio with matching detailing
The second building, located to the left of the main structure, measures 3m x 2.5m and features a mono-pitched roofline with a set of sliding doors on the front elevation. It’s finished in the same vertical black Thermowood as the main building for a cohesive look. Internally, the specification matches the same high standard, with plastered and decorated walls and ceiling, and full insulation.
Inside, the owners have installed a specialist sauna, and Ark Design Build prepared the structure to accommodate the chimney flue required-demonstrating their flexibility in supporting bespoke internal fit-outs.
Learn more about Ark Design Build
If you’re looking for a garden room that breaks away from the ordinary, this project by Ark Design Build is a great example of what’s possible with thoughtful design and precise execution. Whether it’s a home gym, office, or even a sauna space you have in mind, Ark can help you bring it to life.
Telephone: 07896 196 718 Email: contact@arkdesignbuild.co.uk Website: www.arkdesignbuild.co.uk
