How do you convince someone of the potential of a vacant building?

A spacious shop in the city centre is being repurposed for retail and residential purposes. In addition to four apartments, there is space for a retail location on the street side.
The renovation has not yet started, and the owner would like to know how the concept is doing in the market. It is good to know before you make an investment!

The construction drawing has been used as a reliable basis to bring a dimensionally stable 3D model to life. The plan shows two options for realising a catering business or a (flower) shop, including storage, toilets, terrace, and an issue for delivery services or suppliers.

How do you convince someone of the potential of a vacant building?
Ask Beeklander