A sauna in Madrid for the winter and a cold plunge pool for the summer

A plateau, not a coast

There is no sea breeze in Madrid and no salt in the air; what there is, is the sun, and a very wide temperature range between a July afternoon and a January morning. A plunge pool in full shade at 4 °C is easy in May and hard in August; a sauna outdoors is a pleasure on a frosty night and a heater fighting a draught if the door seal is poor. We design for both ends.

Madrid Retiro (WMO normals 1991–2020, Spain's national submission): a mean daily maximum of 33.3 °C in July and 32.6 °C in August, a January mean minimum of 3.0 °C and 417 mm of rain a year. The same terrace sees 33 °C by day in July and close to freezing on a January night, so the plant is drawn for both ends of the year.

Winter: the cabin does most of the work

Madrid's best sauna evenings are cold and clear. A well-insulated outdoor cabin heats in about forty minutes and, with a glass wall, gives a view of a frosty garden: the picture that shows the idea. We specify more insulation than a coastal cabin, a sealed door, a drained base and the heater circuit on a timer, so it is warm when the household comes in from the cold.

Summer: shade, ventilation and the chiller

From June to September the cold pool is the star. Afternoon air is regularly above 30 °C and passes 35 °C for days in a heatwave, so the chiller needs shade and a clear air path, and the pool a cover or a pergola. The plant sits on the north or east side of the building, not on a south-facing patio. See chiller systems.

Frost and the drain-down

A cold pool kept at 4 °C is happy in a frosty garden; pipes, pumps and an unused outdoor circuit are not. We draw the plant with frost in mind: insulated pipework, drain points, a heated cabinet where the plant is exposed and a winter routine on a card. For a second home that is empty from November to March, a drain-down procedure is part of the handover.

Three neighbourhoods, three briefs

• Pozuelo, Aravaca and Las Rozas. Gardens and holm oaks: a garden cabin and a square plunge pool, a plant on the shaded side.
• La Moraleja and Somosaguas. Larger plots and an architect: the cabin of six to eight seats and a hot-and-cold pair, drawn into the architect's plans.
• Salamanca, Chamberí and Retiro. Apartments and terraces: a cabin in a spare room, a free-standing ice bath on the terrace, with the community's consent.

Padel clubs, gyms and clinics

Madrid has many padel clubs, boutique gyms and clinics. A recovery room is the obvious addition; see padel and racquet clubs, gyms and studios and clinics and longevity. The first question on every one is the electrical capacity: ask the distributor whether three-phase is offered, because eight-seat cabins need it.

A sample for a Pozuelo garden

Winter, shade and phases: four Madrid mistakes

• Forgetting the frost. The pool is fine at 4 °C; the pipes, the pump and the unused plant are not. Insulate, drain, and write the winter routine on a card.
• The south-facing patio. A chiller on a wall that bakes from May to September loses a class of cooling. Put it on the shaded side.
• The cabin used only in summer. In Madrid the cabin is a winter object. A design that ignores November has missed the point.
• The three-phase assumption. Do not assume it, in a commercial unit or a villa. Ask for the contracted power and the phases on offer before choosing a cabin.

A year in a Madrid garden

November to March: the cabin, a warm evening and a frosty lawn. April and May: the first plunge, in air that is still kind. June to September: the cold pool carries the garden, the cabin waits for the evening. October: the second spring, and time to check the winter routine. Plan the plant for that calendar and the pool will not be a seasonal toy.

A winter checklist for an outdoor cabin in Madrid

1. The roof membrane and drip edge are clear of leaves and ice.
2. The base drains: nothing is standing under the deck.
3. The door seal is supple and closes tight when cold.
4. The heater's timer is set for the evening and switched to winter.
5. The pool's cover is on, the plant is insulated and the drain points are known.

The Pozuelo sample is two lines of the price list; the kit builder shows how the range changes if the cabin grows to six seats.