Legal Question in Administrative Law in California

Here is a paragraph cut-and-pasted from the WestLaw headnotes to the California Supreme Court's decision in a case called J'Aire Corporation v. Gregory, decided in 1979 and published at 24 Cal.3d 799. You could probably find the full text of the case on line, or at your county law library. The facts are not an exact fit to your case, but close enough, I think, for the principles to apply and suggest you may have a case:

"Lessee brought action against contractor to recover damages arising from the delay in completion of construction project. The Superior Court, Sonoma County, R. Bryan Jamar, J., dismissed complaint, and lessee appealed. The Supreme Court, Bird, C. J., held that contractor who undertook construction work pursuant to contract with owner of premises had a duty to lessee of premises to complete construction in a manner that would avoid unnecessary injury to lessee's business, since contract was for the renovation of premises in which lessee maintained its business, it was foreseeable that any significant delay in completing construction would adversely affect lessee's business, lessee suffered harm because it was unable to operate its business for one month, lessee's injury was closely connected to contractor's delays, contractor's lack of diligence continued after probability of damage was drawn directly to its attention, and public policy supported finding a duty of care in the case.

"Reversed."