Just to answer Steve's question regarding the vacant building and tenant wanting an incentive looking for a 10% discount on rent. I would suggest making some sort of improvement to the building office to the value of a 10% rent discount and leave the rent at the full price. The discount therefore isn't applied to the rent and the value of the property is not affected. Additionally I would try to make the improvement to something that could also improve the value of the building or make the building more attractive not only to this tenant but future tenants.