A flexible training floor with mirrored walls, a roof lantern and garden-facing glazing.
CHESSINGTON, SURREY · A DIRECT TRJ PROJECT
Garden gym with sauna and shower room in Chessington
Train in the daylight. Unwind in the sauna. Refresh without returning to the house.
TRJ Construction delivered this bespoke L-shaped garden building directly for the client. A spacious gym, glazed sauna cabin and separate shower room sit beneath a large roof lantern, with wide glazing opening the interior to the garden.
- Location
- Chessington, Surrey
- Recorded areas
- 61.36 m² external
54.4 m² internal - Spaces
- Gym, sauna & shower room
- Roof lantern
- 5 m × 2 m
01 / THE BRIEF
Room to move.
Space to recover.
The project brings exercise and relaxation into one garden building. The main room provides open training space, a full-height mirrored wall and a dedicated sauna area. A separate bathroom combines a shower, WC, vanity basin and cold-water bath.
Natural light was central to the layout. The 5 m × 2 m glazed roof lantern illuminates the gym from above, while black aluminium glazing frames views across the garden. Bifold doors connect the main room with the decking.
This was a direct TRJ Construction job. Costi and the team coordinated the design, structural work, services and interior finish around the client’s brief.
02 / AN L-SHAPED PLAN
Fitness and facilities.
Planned together.
A timber-lined cabin with glazed doors, corner benches and a Harvia heater.
A separate room with shower enclosure, WC, vanity basin, towel radiator and a cold-water bath.
The original order form records 61.36 m² external area and 54.4 m² internal area. The L-shaped design measures 8.4 m across its wider section and 9.4 m along its longer side; these are overall design dimensions, not the area of a rectangular building.
Original TRJ design illustrations and layout drawings. These show the proposed arrangement; the project photographs below show construction and the finished spaces.
03 / THE STRUCTURE & FINISH
SIP construction.
Steel where it matters.
The building uses Structural Insulated Panels for its base, walls and roof. Steel beams support the larger openings and the roof-lantern span, as shown in the construction photographs.
The order form specifies screw-pile foundations, with the foundation design informed by soil testing and coordinated with Building Control. It also records an EPDM roof covering and ventilation detailing.
Glazing and daylight
Black aluminium bifold doors and fixed glazed panels connect the gym to the garden. Toughened, argon-filled double glazing was specified, alongside an obscured opening bathroom window and the 5 m × 2 m roof lantern.
Exterior finishes
The finished photographs show vertical cladding beneath a projecting canopy, with recessed external lighting and a rendered fascia. The canopy shelters the threshold beside the existing decking.
The training interior
White decorated walls, recessed ceiling lights and dark timber-effect flooring form the interior. The specification includes an additional 12 mm plywood layer to reinforce the floor and a full-height mirror installation.
Heating, cooling and power
The order form records a 3.5 kW Wi-Fi-enabled air-conditioning unit, electric panel heating, Ethernet cabling and a dedicated electrical board with circuit protection. The sauna supply and supporting services were planned with the main building.
Bathroom services
The shower room includes ventilation and an electric towel radiator. The specification records pumped waste drainage, plus water and drainage provision for the cold-water bath.
Sauna and recovery
The completed sauna has timber linings, tiered corner benches and glazed access. The order form left the sauna model for later selection; the photographs show the installed cabin and Harvia heater.
04 / THE PROJECT IN PHOTOGRAPHS
From the structure
to the finished rooms.
Explore the gym, sauna, bathroom and exterior, then follow the SIP and steelwork through the construction photographs. Select an image to see it at full size.
A direct TRJ Construction project in Chessington, Surrey. Original design visuals and project photographs supplied from the TRJ project record.
05 / PROJECT QUESTIONS
A few useful answers.
Where is this garden gym and sauna?
The project is in Chessington, Surrey.
How large is the garden building?
The original order form records an external area of 61.36 m² and an internal area of 54.4 m². It has an L-shaped layout, with overall design dimensions of 8.4 m by 9.4 m.
What facilities does it contain?
An open gym, a timber-lined sauna and a separate bathroom with shower, WC, vanity basin and cold-water bath.
Who delivered the project?
TRJ Construction delivered the project directly for the client, coordinating the design, SIP construction, steelwork, services and finishes.
How does the room get its daylight?
A 5 m × 2 m roof lantern lights the interior from above, alongside large glazed panels and bifold doors facing the garden.
YOUR NEXT PROJECT
Your own space.
Your complete brief.
Planning a garden room with a bathroom or a home garden gym? Tell Costi how you want to use the building, the space available and which facilities you need.
Explore our bathroom and shower-room options, build process and planning guidance.
