A wellness room in the house, not a cabin in the garden

The sequence along one wall

Our standard indoor layout is a short corridor with the sauna door, the steam room door and the plunge basin opening off one wall, and a bench opposite. It keeps every wet surface on one drainage line, keeps the plant behind a single access panel, and means you walk three steps from heat to cold rather than through a dry corridor with a carpet on it.

The three services you cannot retrofit cheaply

Drainage: every wet room needs a fall and a trap, and adding one to a finished slab means breaking it. Ventilation: a mechanical extract with a run-on timer, ducted out — not a window. Power: the sauna's three-phase run and the chiller's circuit, both back to the board.

Get those three into the build drawing and the rest is finishes. Miss them and the project becomes demolition.

Light, sound and where the towels go

The things people remember are the small ones: a dimmable warm light under the bench instead of a ceiling downlight in your eyes, a door that closes on a soft catch, a heated rail so towels are dry the next evening, and a shelf at the plunge for a glass of water. We draw them in because nobody adds them later.

In short

• Sauna, steam and plunge along one wall — one drainage line, one plant panel
• Drainage, ventilation and power resolved in the build drawing, not on site
• Mechanical extract with run-on timer, ducted out — a window is not ventilation
• Warm under-bench lighting, soft-close doors, heated towel rail, a shelf at the plunge