Limiting the growth of final energy demand helps meet the steep greenhouse gas (GHG) reduction trajectories required to address climate change, and can also bring wider sustainability benefits. Integrated Assessment Modelling (IAM) and energy systems modelling analyses are increasingly including low energy demand (LED) measures in GHG mitigation scenarios, but their granularity and empirical basis is typically low, limiting actionable insights. Here, we contribute to addressing this gap by examining the role of spatial settlement patterns as a driver of energy service demand, particularly in the transport and residential sectors. We focus on Ireland, which has enacted ambitious decarbonisation commitments in law, that are challenging to deliver partially due to a large proportion of the population living in rural one-off housing.