Cube Saunas
Ebony Cube.Harvia heater, mirror-glass door.
The ebony cube specification with a reflective mirror-glass door and Harvia heater, privacy from outside, panoramic view from inside.
Overview
Ebony Cube Sauna, Harvia Mirror Door.
This variant of the ebony cube specifies a one-way mirror-glass door and a standard Harvia heater, for owners who want privacy from the outside without giving up the panoramic view from inside.
The mirror-glass is a specialised reflective toughened panel: from the garden side it reads as a bronze-mirrored surface reflecting the surrounding planting. From inside the sauna, sitting in ambient light, it's fully transparent, you look out at the garden without being watched.
It's the specification we recommend for overlooked urban gardens, close-boundary installations, and short-let properties where the sauna is visible from a public footpath. The Harvia heater keeps the price under the HUUM Black Glass edition without compromising the exterior look.
Key features
What makes it different.
Mirror-glass reflective door
One-way bronze-mirrored toughened glass, private from outside, panoramic from inside.
Shou Sugi Ban ebony cladding
Charred and oiled spruce exterior, deep matte black.
Harvia 9kW electric heater
Finnish-made industry-benchmark heater with rock cradle and digital control.
Fully-insulated cube
100mm rockwool insulation, vapour barrier, hemlock interior lining.
3–4 person capacity
Single-tier bench for architectural clarity. Two comfortable, four social.
Ideal for overlooked gardens
Solves the privacy problem for urban and close-boundary installations.
Specification
The numbers behind the object.
- Capacity
- 3–4 adults
- External footprint
- 2.2 x 2.0 m
- Interior ceiling height
- 2.1 m
- Cladding
- Shou Sugi Ban charred spruce
- Door
- Toughened bronze-mirror glass, one-way
- Insulation
- 100mm rockwool
- Lining
- Knot-free western hemlock
- Heater
- Harvia electric 9kW
- Heat-up time
- ≈ 30 minutes
- Power requirement
- 32A single-phase
- Warranty
- 10 yr structural
Living with it
How it actually works day to day.
The mirror door is a genuine solution to a real problem. Overlooked gardens, terraced houses, small courtyards, close-boundary new-builds, mean panoramic-glass saunas can feel exposed. The bronze mirror is an elegant answer.
The one-way effect depends on ambient light. Inside the sauna at ~150 lux (a low ambient level), you look out to a garden lit by daylight or normal outdoor lighting and it reads as clear glass. From the garden side at daylight levels, the door reads as a bronze mirror.
In pitch dark on both sides, sauna and garden, the effect breaks down. In practice this only matters at night with no outdoor lighting and the sauna interior lit; a soft warm dimmable LED is our recommended solution.
Best for
Who typically buys this one.
- Overlooked urban and terraced gardens
- Close-boundary new-build gardens
- Short-let properties visible from footpaths or neighbouring properties
- Owners who love the panoramic view but need outside privacy
Real installations
Ebony in Scottish gardens.
Every photograph on this page is a genuine Signature Garden Rooms installation.
It's a specialised toughened panel with a reflective bronze coating on the outside. From the brighter garden side it reads as a bronze mirror; from the dimmer sauna interior it's fully transparent. The effect relies on the interior being darker than the exterior.
Next step
Ready to talk about the Ebony Cube Sauna, Harvia Mirror Door?
Tell us your garden, your access, and roughly when you'd like it in. We'll come back with a considered price, honest lead time, and any planning notes for your site.
Fully insured · £5m public liability · Falkirk-based, working across Central Scotland