Social Housing Construction in Ireland; Achieving Nearly Zero Energy Building (nZEB) Standards Through Passive House Methodologies and Renewable Energy Systems

Since 2018, nearly Zero Energy Building (nZEB) standards have become effective on all public buildings, and since 2020, for all new build dwellings in the European Union (EU). This standard requires buildings to have a high-energy performance as defined in the EU Energy Performance of Buildings Directive Recast 2010. Passive House (PH) standards require high-performance dwellings to achieve a consistently comfortable internal environment. In Ireland, over 97,000 new social homes are to be built between 2022 and 2030, thus, there are huge sustainable opportunities for social housing construction. This research aims to establish capital and operating costs of passive housing versus typical housing construction in Ireland and to identify energy-efficient solutions to reduce space heating energy demands in households. A mixed-method research approach is utilised, incorporating a literature review, a case study, semistructured interviews, and a questionnaire survey with experienced professionals within the Irish construction industry. Findings show that additional construction costs were associated with increased airtightness, extra quantities of insulation, mechanical heat recovery systems as well as higher-performing windows and doors. Cost reductions are achievable by changing from the conventional heating system and removal of the chimney stack. Challenges such as inflated material costs, workmanship, finances, and airtightness were identified. Passive Houses are outstandingly cheaper to operate in comparison to an average dwelling in Ireland. Renewable energy systems such as solar photovoltaics, air source heat pumps, and mechanical heat recovery systems offer substantial savings over time. Low-income tenants and homeowners are negatively affected by energy inefficiency as it affects their dietary decisions, disposable income, and both physical and mental health due to financial stress. Ultimately, the key contribution of this research illustrates that while higher initial expenditures are incurred, nZEB dwellings built to Passive House standards are a viable solution for social housing in Ireland while offering various benefits.