The "Paulis Hook" section of Jersey City $($NJ$)$ is a largely upper middle$-$class residential area characterized by townhouses and midrise apartment blocks. Bordering the neighborhood to the East are ferry and subway $($Path$)$ services to Manhattan and Type$-$A high$-$rise office buildings. Paulis Hook is also home to the $($under construction$)$ site of NJ$\text{'}$s tallest residential tower, which is marketed to high$-$net$-$worth individuals.

Developer X believes that due to Manhattan's constrained real estate and Paulis' advantages over NYC$\text{'}$s outer boroughs, its housing prices will continue to rise, and much of the area will be rezoned for high$-$rise residences over the next decade. X plans to purchase one of the few remaining run$-$down, several$-$story rental buildings in the neighborhood, perform a gut rehab, and then sell it to an Asset Management firm. What is the $\%$ of gut rehab cost in the total project cost?