Periodic refurbishment and reductions in national costs to sustain dwelling services

This paper uses a simulation model to make exploratory estimates of current and potential reductions in national costs to sustain dwelling services due to refurbishment. Data and parameters are based on a typical New Zealand dwelling of lightweight timber framed construction. Dwelling service years provided by a dwelling over one year adjusted for depreciation serve as a proxy for benefits. The costs to construct one dwelling and fractions thereof serve as a proxy for the costs of maintenance, refurbishment, replacement, and new construction. Current levels of refurbishment reduce national average costs to sustain dwelling services by a magnitude of 15%. Potential reductions in national costs are modest (5%) should the housing stock be stationary, but are negligible when the expansion rate of the housing stock is as high as 2.0% per year. A decline in the expansion rate of a housing stock has a greater impact on reducing national costs than an increase in the number of cycles of refurbishment.