The lease-up period is the amount of time needed to find tenants for a newly developed or renovated rental property. The size and location of the property, the state of the rental market, the quality and kind of units, the extent of marketing and leasing efforts, and the level of competition all play a role in determining the lease-up duration. The lease-up time, which normally ranges from 90% to 100%, is calculated by counting the days between the first unit's availability for rent and that date.