This research paper explores what impacts regional regulation, and the resulting planning process, has on ground-related housing. The Growth Plan for the Greater Golden Horseshoe (Growth Plan) is a significant regulation requiring evaluation. It has been suggested that density targets mandated by the Growth Plan have continuously decreased the supply of ground-related housing in the Greater Golden Horseshoe (GGH). The combination of regional regulations and the time of processing development applications play an important role in understanding changes in housing supply. A case study of York Region displayed this concept, such that the requirements of the Province, and the resulting changes to the planning system for the Region, has contributed to decreases in supply of ground-related housing. Prices continue to rise due to increasing demand for the housing type. This research suggests four recommendations for the Proposed Growth Plan to increase the inventory of ground-related housing: 1) reducing density targets, 2) realigning the planning process to reduce time lag, 3) observing market demand, and 4) removing a one-size-fits-all policy which currently exists within the Growth Plan.