The answer is simply: as late as possible. Select your chosen design and suitably qualified supplier when your concrete work is done and measurable. Leave the installation process for as late as possible in the program for the following reasons:

1.The balustrades should be installed by using the core drilling method if top fixed, for the uprights, which after tiling will create a neat continuous tiling line.

2.Tile adhesives and acid-based tile cleaning agents will affect the finish of the stainless steel and corrosion marks could become evident. If you are installing wooden floors or carpets, it is advisable to install the balustrades first as core drilling is a wet process which could cause water damage.