Deterioration Rates of Building Component Groups Using Nominal Replacement Costs of Components

Predictive modeling of deterioration is typically done based on visually inspected condition ratings of building components. This paper presents the concept of a cumulative lost value ratio (CLVR) for component groups to track their deterioration with time. The CLVR is computed through the estimated nominal replacement costs and times for the components that form the group in a given building. This eliminates the need for condition surveys and enables a much larger proportion of building assets to be modeled. Data from the City of Melbourne indicated that eight building component groups encapsulated 87% of building value. The similarities observed in their deterioration patterns were used to allocate them into four categories: (1) superstructure; (2) finishes; (3) fittings, plumbing, and water; and (4) air-conditioning, fire, and electrical. Next, for each year, the proportions of buildings with a given component group in each of five CLVR ranges (C1-C5) were established and fitted with Markov deterioration models. The best fits were obtained for the superstructure and finishes groups and also for Conditions C1 and C5.