A commercial unit nobody wanted to paint, an aluminium flight case, and how discretion won NU Projects two years of work for the Princess of Pop.

NU Projects met David Gandy standing in a Fulham coffee queue. What followed was a basement, an extension, a full renovation, and a nickname from Kylie.

Most renovation quotes are a single number you cannot interrogate. An open-book estimate shows the working, here is what to look for and what to ask.