Data availability has been an issue in tracking changes in the condition of housing at the neighborhood level. Census data are of limited use, and other methods are expensive, time-consuming, and subject to bias. This paper proposes a methodology that uses variables obtained from property assessor files to develop estimates of the condition of the housing stock. The property appraiser provides parcel level information on housing units. The measure developed, the ratio of market value to unit value new, can be used to estimate the quantity and degree of substandard housing in a community. This variable implicitly incorporates other variables thought to be important in the determination of housing condition including age, size, and tenure of the unit. This study is unique in that it establishes a single measure of housing quality, it is relatively simple to implement, and it relies on data that is easy to obtain.