The IAQ performance-based regulation in Spain: description, identified problems for its application, and foreseen changes

Efforts must be made to promote the use of efficient ventilation systems in buildings with the aim of reducing energy demand, as ventilation is a major source of energy loss. Nevertheless, the implementation of efficient ventilation systems is frequently constrained by regulations. It is therefore essential that governments and regulatory bodies facilitate and even encourage the use of appropriate solutions through the introduction of performance-based regulations. 
Prescriptive regulations establish particular conditions or specifications for deemed-to-satisfy solutions or systems, thereby limiting the utilization of any alternative solution or system. In general, indoor air quality (IAQ) regulatory frameworks worldwide are still mainly based on prescriptive approaches that set fixed requirements for airflows or air change rates. This can hinder the implementation of innovative and more efficient ventilation systems. 
In contrast, performance-based regulations provide a flexible regulatory framework that can accommodate any solution that meets the specified performance requirements, regardless of whether it is explicitly outlined in the regulations. This approach allows for innovation, promoting the utilisation of novel techniques and building practices that result in enhanced efficiency (IRCC, 1998). Therefore, to promote the use of efficient ventilation systems, it is imperative to develop and implement performance-based IAQ regulations that require IAQ performance indicators during the building design stage. A number of countries have already implemented performance-based IAQ regulations with the intention of encouraging the use of efficient ventilation strategies. 
This paper presents a description of the IAQ performance-based regulation in Spain, along with an analysis of the main identified problems for its application and the anticipated changes that are likely to occur in the near future.