The New Health Impact Assessment (Wales) Regulations: A Framework for Advancing Health Equity in Wales 

Health Impact Assessment (HIA) is an approach that brings together a combination of procedures, methods and tools to evaluate how a proposed decision, initiative, policy, programme, or project may affect the health of a population.  

In Wales, the innovative HIA approach has been recognised through legislative change. The Health Impact Assessment (Wales) Regulations 2025, passed by the Senedd on 19 November 2025, requires public bodies to place health, well-being and equity at the centre of their strategic decision-making processes. The Regulations define a HIA as “an assessment of the likely effect, both in the short- and long-term, of a proposed action or decision on the physical and mental health of all or some of the people of Wales”.   

At its core, HIA embeds a strong health equity lens, ensuring that decision makers critically assess potential impacts on vulnerable, disadvantaged or under-recognised groups. This approach is particularly effective when applied early in the decision‑making process. A HIA examines existing and potential health inequalities across population groups that may be affected. In so doing, the approach can be utilised to offer recommendations that improve health outcomes by strengthening and maximising the positive effects of a proposed decision on health and well‑being, while also helping to identify and mitigate any negative or unintended consequences.  

Some examples where HIA approaches have been used include within the sectors of transport, agriculture, energy, waste, and housing. Cognisant of the wider determinants of health, the approach considers and seeks to mitigate the ways in which these factors impact population health, also embedding a Health in All Policies approach.  

Wales Leading the Way: The Role of Public Health Wales in the Legislation 

Wales is distinguished as the first nation to take this legislative step, aligning it with other key national policies like the Well-being of Future Generations (Wales) Act 2015.  

Public Health Wales (PHW) has played an instrumental role in shaping and supporting the implementation of the Regulations. In particular, the Wales Health Impact Assessment Support Unit (WHIASU) within PHW, through a joint Project Board, is supporting the implementation of the legislation. WHIASU has been conducting and supporting HIAs since 2001 across a variety of sectors and with a variety of scopes, sizes and lengths of projects, policies and strategies.  

WHIASU is supporting public bodies by developing a suite of resources including:  

• A statutory HIA guide for public bodies 

• Direct support to public bodies to upskill staff through training and workshops 

• Published case studies and reports 

• A web resource with information and tools 

WHIASU aims to build on this in the future by contributing to the Welsh Government on the monitoring and evaluation of the regulations.  

HIA: Process and Expected Impact 

The Regulations will come into effect in April 2027, at which point public bodies in Wales including local authorities, national parks, NHS bodies, and national cultural and sporting institutions such as the National Museum, the National Library and Sport Wales will be legally required to undertake HIAs when proposing to make decisions of a strategic nature about how to exercise their functions. 

Decision-making across a broad range of policy areas can profoundly influence long-term health outcomes. In a written statement, the Welsh Government noted that “HIAs will make sure physical and mental health impacts are consistently taken into account when public sector organisations develop new policies or projects”. This includes within sectors such as housing, transport, education, employment, culture, and environment.  

The introduction of mandatory HIAs aim to: 

• Improve population health and well-being 

• Reduce health inequalities and address wider determinants of health 

• Embed health considerations into routine public decision-making 

• Ensure consistency and improve decision-making quality across public bodies 

• Support the Well-being of Future Generations (Wales) Act 2015 and the Socio-economic Duty 

• Position Wales as a global leader in public health policy and legislation 

For more information on HIA principles, methodologies, and general guidance in Wales, visit the WHIASU webpage.