This constitutes the difference between the reasonable rental value of the unit in its defective condition and the agreed upon rent. This may be determined on a percentage basis without expert testimony. The abatement is granted only for the period of time that rent was withheld, however. This is not to say that a landlord does not have an obligation to make repairs that do not affect the habitability of the residential rental property. If the defects do not go to habitability, the tenant can, after giving the landlord a reasonable opportunity to fix it, fix it himself, and sue the landlord for the costs of repair.
Habitability is what allows a tenant to escrow rent for that purpose.
The doctrine of the implied warranty of habitability has been applied to non-residential tenancies as well. For example, abatements have been granted to professional office tenants and to other commercial tenancies having to do with problems with a parking lot. When a tenant signs a lease for a rental property, here she is agreeing to be responsible for monthly rental payments during the complete term of that lease. Although this applies to both commercial and residential tenancies, the example of a typical one year lease of a residential property will be discussed here. A tenant should provide the landlord with written notice of premature termination as far in advance of the departure date as possible, in order to give the landlord the greatest opportunity to re-rent the premises.