The Building Safety Regime in Wales: a guide to higher-risk buildings and dutyholder obligations during the construction phase

Why this matters:

From 1 July 2026, Wales will introduce a new building safety regime. Implemented through two key pieces of secondary legislation, the changes will reshape how building safety is regulated and how higher-risk building (“HRB”) projects are defined, approved and delivered in Wales.

These reforms affect developers, contractors and property stakeholders operating in Wales, introducing a distinct dutyholder regime for all building work and a broader HRB definition, with new procedural requirements governed by local authority building control rather than a central regulator. 

Whilst the Welsh regime broadly mirrors the approach taken in England, there are important differences that those working on qualifying projects will need to understand. Crucially, Wales departs from the English approach by not recognising independent sections for works to existing HRBs, meaning one qualifying aspect can bring an entire HRB within the regime. 

This article will help you understand whether your projects fall within scope and how to manage new compliance obligations following implementation. Those delivering projects in Wales must ensure jurisdiction-specific compliance to avoid delay, cost escalation and regulatory risk.

Welsh Dutyholder Regime:

The Welsh dutyholder regime is introduced by The Building etc. (Amendment) (No. 2) (Wales) Regulations 2025 and will apply to all building work under the Building Regulations 2010 in Wales (not just HRB work). The dutyholder regime is subject to transitional arrangements and therefore the pre 1 July 2026 regime will continue to apply if building work has started, plans have been deposited with a local authority or a building notice has been given to a local authority.

While the regime broadly aligns with the approach taken in England, there is a notable divergence in its treatment of domestic clients. In Wales, a domestic client – that is, a client for whom a project is being carried out otherwise than in the course or furtherance of a business - may elect to assign the duties of Principal Designer and Principal Contractor to themselves or another person, provided a written statement is submitted confirming the responsibilities are understood. For HRB works, this statement must form part of the building control application. If no appointment is made, the relevant duties will generally fall to the Contractor, Principal Contractor or Principal Designer, depending on the circumstances.

This approach introduces greater flexibility but also potential risk around competence and accountability, particularly on smaller or non-professional client-led projects.

Definition of an HRB in Wales:

The definition of an HRB in Wales is set out in the Building Safety (Description of Higher-Risk Building) (Design and Construction Phase) (Wales) Regulations 2023. A building will fall within scope where it reaches at least 18 metres in height or comprises seven storeys or more, and contains certain specified uses.

These include:

• buildings with one or more residential unit;
• those used as care homes, children’s homes;
• hospitals where at least one bed is intended for overnight patient accommodation.

Certain buildings are excluded, including:

• secure residential institutions;
• hotels; 
• military barracks;
• accommodation for the Ministry of Defence or His Majesty’s forces. 

These exclusions reflect a focus on permanent residential and care settings rather than temporary or operational accommodation.

Importantly, the Welsh definition departs from the equivalent regime in England in two key respects:

1. whereas the English legislation requires at least two residential units, the Welsh regime captures buildings with only a single residential unit; and
2. children’s homes are expressly included in Wales but excluded in England.

In practice, these differences expand the scope of regulation in Wales, meaning that a broader range of developments may be subject to enhanced building safety requirements.

Welsh HRB Procedures Regulations:

From 1 July 2026, The Building (Higher-Risk Buildings Procedures) (Wales) Regulations 2025 (the ‘HRB Procedures Regulations’) will govern how building control applications for higher-risk building work in Wales are submitted and determined. Transitional arrangements will apply where full plans have been deposited with a building control authority or an initial notice has been given and accepted (or deemed accepted) before 1 July 2026. In these cases the requirements of the Building Regulations 2010 and where applicable the Building (Registered Building Control Approvers etc.) (Wales) Regulations 2024 will continue to apply as they stood before 1 July 2026. 

The procedural framework governing HRBs in Wales is set out in HRB Procedures Regulations. While broadly aligned with the English regime, there are key differences in how projects are administered.

Most notably, the local authority building control is responsible for administering the application and approvals (rather than a centralised regulator such as the Building Safety Regulator in England). 

The appeals process also differs. Appeals against certain decisions, such as a rejection notice determining that work has commenced, must be made to the Magistrates’ Court, while other building control decisions are appealed to the Welsh Ministers, rather than the First-tier tribunal or the Secretary of State as in England. 

In addition, the timeframe for appeals is shorter; with parties having 15 working days from notification, compared to 21 relevant days in England. 

In practice, this means that developers and project teams must work closely with local authorities and be prepared to act quickly when decisions are challenged. 

There are also further practical differences. The client may nominate a person to act on their behalf when notifying the building control authority of the intention to start work and when confirming that work has commenced. Unlike in England, there is no requirement to provide details of what the client considers would amount to 15% of the proposed work when giving notice of commencement. 

There is also no obligation on the building control authority to notify the applicant that a building control application is invalid or to provide reasons for invalidity. Additionally, a building control approval application for work to an existing HRB must be accompanied by reports or calculations demonstrating compliance with building regulations where the work will affect the structural load of the building. 

The definition of a "major change" is also broader in Wales, capturing a change to any product or building element used as part of the HRB, rather than being limited to those used in or on a proposed HRB. In practice, this broader definition means that changes to a wider range of building elements during construction may trigger the major change notification requirements.

On completion of the works, the client must provide specified fire safety information and golden thread information to the “responsible person” (i.e. the person under the Regulatory Reform (Fire Safety) Order 2025) no later than the date the work is completed, rather than the “relevant person” (which, in England may also include an accountable person). 

These procedural differences mean that projects cannot simply adopt English compliance processes without modification.

No ‘independent sections’

A further distinction between the Welsh and English regimes is the absence in Wales of any concept equivalent to “independent sections.” Under the English framework, this concept allows certain parts of an existing HRB to be treated separately so that the wider HRB regime does not apply. 

In contrast, the Welsh approach is intentionally more rigid. Where any part of a building meets the relevant height, storey and use thresholds, the entire building will be classified as an HRB – there is no mechanism for separating out parts of the structure that might not otherwise qualify. 

The Building Safety (Wales) Act 2026 introduces the concept of an “independent part” but this relates to the occupation phase. The absence of independent sections in the design and construction phase represents a key differentiator and a potential source of increased regulatory exposure for developers in Wales, particularly where there are mixed use developments.

This has clear implications for design strategy, cost planning and regulatory scope, and removes a flexibility that exists under the English system.

Takeaways:

For clients in the construction and property management sectors, these changes present both challenges and opportunities. While heightened compliance requirements may impact project timelines and costs, they also offer improved safety and risk management, potentially enhancing long term value. Clients should ensure robust compliance strategies, engaging competent dutyholders, and maintaining comprehensive safety records.

Those involved in the design and construction, or management of HRBs in Wales should be reviewing their processes and ensuring that project teams are aware of the differences between the Welsh and English regimes. Those involved in the management and occupation of HRBs should also consider the Building Safety (Wales) Act 2026 which also differs substantially from the position in England and includes varying rules for different categories of building.

For more information

What do I need to know about England’s new dutyholder regime under The Building Regulations 2010?