Swell Sport · Practical guide

How to read a sauna specification sheet without guessing

Read a sauna specification sheet by asking what each number measures, which model it belongs to and what it does not tell you. Mark unanswered questions directly on a copy before using the sheet to choose a cabin or brief an installer.

Swell Cedar Cube 2 in a home setting.

Annotate the dimensions before drawing the footprint

External dimensions describe the stated outside size; they do not by themselves describe usable seating or all space required around the installation. Mark the order of dimensions and their units. Ask whether projections and roof edges are included, and use the dimensioned drawing when an exact fit matters.

For a concrete example, the Cube 2 listing gives external dimensions of 136 cm wide, 135 cm deep and 210 cm high. Label those as external cabin dimensions on your notes, not as a bench measurement or a complete installation clearance. Ask for the internal layout and applicable installation requirements separately. ^[1]

Treat capacity as a layout question

Beside a person rating, write “check seating arrangement”. Ask for bench length, depth, levels and the position of the heater and door. Think about the posture and personal space the intended users want. A capacity label should start that conversation rather than replace it.

The useful comparison is between actual usable arrangements, not simply two external rectangles. Try the intended seating position in a display if available, or request a clear dimensioned plan. Avoid promising that every person can stretch out because a cabin is described as suitable for a particular headcount.

Separate power, energy and temperature claims

Where a sheet lists heater power in kW, record it as the equipment’s stated power rating. Do not label the same number as energy used per session, which would be expressed in kWh. Ask for the assumptions behind any energy or warm-up estimate rather than deriving a universal session cost from one specification.

Copy the heater code and control package beside that rating. The Cube 2 product page directs the licensed electrician to size the dedicated circuit to the selected heater manufacturer’s installation requirements. The sheet is an equipment input for that assessment, not permission to choose a breaker or connection method yourself. ^[2]

Read material descriptions literally

Circle species, thickness and which components the description applies to. The current Cube 2 listing states solid 38 mm Japanese cedar. Preserve that identity in your comparison; do not change it to another cedar species or treat the word “solid” as proof of every other feature of the cabin. ^[3]

Keep roof, glazing, hardware and finish as separate entries. Ask for evidence behind any additional rating or performance claim. A timber specification is not automatically a fire classification, a wind rating, an insulation test or an environmental certification. Leave those boxes unanswered unless the actual documentation establishes them.

Worked annotation: a sheet that looks complete

Imagine a sheet with external dimensions, a capacity label and heater power but no bench drawing, package code or definition of installed clearance. It is useful for an initial shortlist, but not yet enough to finalise a tight site. Your annotation should request those missing items rather than fill them from a photograph.

Finish with a document-control check. Record the sheet date, model, selected option and drawing revision. Ask the supplier to reconcile conflicting figures before the installer uses them. The result is a short list of precise questions and trustworthy inputs—not a pile of numbers that appear more certain than they are.