Building on a terrace twenty floors up

The lift sets the panel size

We measure the service lift — height, width, depth and diagonal — before quoting anything, and design panels that pass it with room to turn. A panel that fits the drawing but not the lift is a very expensive afternoon and a conversation nobody enjoys.

Where a component genuinely cannot go up the lift, the options are a redesign or a crane lift, and both belong in the quote rather than in a phone call during the build.

The slab, before anything holding water

A 900-litre tub is close to a tonne once filled, and a tiled plunge basin is more. On a suspended terrace slab that is a structural question with a real answer, and we get an engineer's opinion before quoting rather than after. This is one of the few things we refuse outright.

The waterproofing is the second half of the same problem: a terrace membrane that was designed for rainwater is not automatically a membrane that will live under a permanently wet installation. We check it, and where necessary we detail a new one properly.

Drainage, noise and the management company

Terrace drainage has to take a full tub emptying without backing up into the apartment below, which is more water than the outlet was sized for. We design the discharge rather than hoping the existing gully copes.

Then there is the body corporate: a drawing, an elevation, a plant position and a noise figure. We prepare the submission, because a cabin refused after delivery is an expensive lesson and plant on anti-vibration mounts inside a louvred enclosure is what gets approvals through.

In short

• Service lift measured before a price is given
• Engineer's opinion on the slab before quoting anything holding water
• Terrace membrane checked, and re-detailed where necessary
• Body-corporate submission prepared with a drawing and a noise figure