Plein travaux/tenants?

Had a nasty surprise today when I went to see a beautiful rental apartment for a new relocation client this week. The owner had neglected to tell me the whole coutyard of the building was in plein travail: dust, noise, ten workmen, scaffolding, various buckets of Seine coloured liquid. It looked like they'd just started too but I found out later it was supposed to have finished in December 2005! This is a risky part of being a home owner in Paris. When Travaux starts, it can be interminable and if you have bought an apartment to rent out it can decimate your chances of finding a tenant, and more importantly, keeping them happy.