Time to build: Rules-based planning and construction project duration in Dublin

Abstract

Housing is one of the most politically salient issues in high-income countries, with an increasing focus on the determinants and responsiveness of supply and on policy options such as upzoning and use-by-right. This paper examines the determinants of the duration between receiving planning consent and commencing construction (activation), and between commencing construction and completion of new housing units (build-out). A simple economic model, incorporating uncertainty around planning decisions as well as capital costs and payment structures, generates four propositions. These are then taken to a new and detailed database of 83,000 residential units across 5,300 proposed developments in Dublin, Ireland for the period 2018–2023, with rich information on project, site and firm characteristics. The setting includes a baseline discretionary planning system and two more rules-based planning codes for certain projects. We find empirical support for all four propositions from theory, including clear evidence that, where systems of land use regulation are more certain, activation times are shorter. These findings have considerable relevance for policies that seek to increase housing supply.