Swell Sport · Practical guide

Surveying a sloping site for an outdoor sauna

A sloping sauna site needs a record of levels and water movement before it needs a choice of paving. Prepare a small information pack that shows the proposed position in relation to the house, garden terraces and access route. The useful outcome is a brief a surveyor, builder or engineer can work from, not a do-it-yourself foundation drawing.

Swell Cedar Cube 2 in a home setting.

Make a location sheet before a levels sheet

Sketch the house, fences, existing walls, steps, visible drains and two possible sauna positions. Give each position a letter and mark the proposed doorway. Photograph each from the same uphill and downhill viewpoints. Include the approach from the delivery point: an appealing level corner is less useful if the only route to it crosses an unresolved terrace.

Keep estimates visibly separate from surveyed information. Label an approximate distance as approximate, and leave the ground-level field blank if it has not been measured professionally. A phone photograph can explain the shape of a garden; it should not become the source of construction levels.

Ask for levels that answer the actual design question

Give the surveyor a list of points you want related to a common reference: proposed cabin corners, doorway landing, nearby house thresholds, top and bottom of retaining walls, and drainage features. Ask the designer which additional points are needed before commissioning the survey. This avoids paying for an attractive drawing that misses the critical downhill edge.

Request a section through the slope as well as a plan view. Ask the designer to show existing and proposed levels separately and identify any cutting, filling or retaining proposal. Record who will decide whether further ground investigation is needed; do not convert an approximate rise into a footing detail.

Record water without redesigning the garden

From a safe position, note where rain arrives, crosses the candidate area and leaves it. Distinguish an observed flow from a guessed underground pipe route. QBCC’s residential guidance describes soil movement associated with changing moisture content; it is a reason to include water history in the brief, not a sauna slab specification. ^[1]

Add service records before proposed ground works are priced. BYDA warns that supplied plans are indicative and may omit details inside the property boundary. Put unresolved service locations on the drawing rather than treating an empty plan as clear ground. ^[2]

Compare two positions using the same questions

In a hypothetical terraced garden, position A is close to the back door but above a wall; position B is farther away with a simpler approach. Do not choose A on walking distance alone. Ask for the proposed support solution, drainage route and access method for each position, with unknowns and investigation costs listed separately.

For a shortlisted Cube, attach the exact model drawing rather than substituting a generic garden-cabin rectangle. Request its support layout and installation requirements from Swell. Keep the owner’s sketch labelled as a briefing document until the responsible professionals issue their drawings.

Your practical checklist

Name both candidate positions on every photograph.
Request a common level reference and a section through the slope.
Log visible runoff and unknown services separately.
Compare scope, unresolved investigations and access—not just base price.

Can I estimate the slope myself?

You can record observations for the initial discussion. Use surveyed levels where the designer requires them; do not issue an estimated fall as a construction instruction.