Saunas built against the granite

The plinth is granite, because the granite is already there

The Inner Seychelles are the world's only granitic ocean islands, and on most sites the rock is not an obstacle to be removed but the best foundation available. We set cabins on plinths built from split granite, pinned where necessary into the bedrock, which is both cheaper and more permanent than a poured slab on a steep site.

Where the ground is genuinely too steep we use a galvanised steel sub-frame on pad footings, sized by an engineer. What we do not do is bench into a slope and hope; on this geology that is how you find out where the water runs.

Marine specification, every time

There is no inland here. Every site gets A4 stainless throughout including fixings nobody sees, end grain sealed before assembly, a ventilated void under every cabin, drained and vented cavities, and a sealed filtered enclosure for anything with a condenser.

Humidity is constant rather than seasonal, so nothing ever dries out on its own. The specification is about giving moisture a route back out, not keeping it out.

Sizes and glazing

From a two-person cabin on an apartment terrace to a fourteen-seat commercial tier for a resort. Glazing is where most of the design decisions land: a single glass wall facing the sea, or two meeting at a corner with no post between them so the corner disappears.

Every square metre of glass costs about 0.4 kW of heater, and we put that in the calculation rather than discovering it at commissioning.

In short

• Granite plinths pinned into bedrock instead of slabs on a slope
• A4 stainless, sealed end grain and ventilated voids as standard, not an upgrade
• Panels sized to the actual carry route, surveyed before quoting
• Glass loss inside the heater calculation, shown as its own line