Wales is one of the newest — and least understood — markets in Building Safety Act compliance. Many building owners, managing agents, and even some consultants still assume the England regime applies uniformly across England and Wales. It doesn't. Wales has developed its own, genuinely distinct approach, and in the case of existing occupied buildings, one that reaches considerably further down the height scale than most people expect.
This guide sets out how the regime actually works in Wales, where it diverges from England, and — critically — why buildings that wouldn't register as a concern under the English rules can still carry a legal structural safety duty in Wales.
Two Separate Regimes, Not One
It helps to treat Wales as having two related but distinct pieces of building safety law, rather than a single set of rules:
- Design and construction phase — Wales has its own secondary legislation implementing the Building Safety Act 2022 for Higher-Risk Buildings under design and construction, broadly mirroring England's Gateway 2/3 process but with meaningful differences (set out below).
- Occupation phase — Wales has gone further with the Building Safety (Wales) Act 2026, a standalone piece of Senedd legislation covering existing, occupied buildings. This creates a "regulated building" framework with no direct equivalent in England.
How the Design & Construction Phase Differs From England
For new-build and major refurbishment Higher-Risk Buildings, Wales largely mirrors the England approach — but with several practical differences worth knowing if you work across both jurisdictions:
- Lower residential-unit threshold — a Welsh Higher-Risk Building only needs to contain one residential unit at 18 metres / 7+ storeys, compared with two or more in England.
- Welsh local authorities as building control authority — rather than a single centralised regulator, Welsh local authorities carry out the building control authority role for HRBs.
- Longer notice period — five working days' notice is required before starting certain building work, compared with two days under the standard regime.
Why Shorter Buildings Are in Scope in Wales
This is the part that catches people out. The Building Safety (Wales) Act 2026 introduces a three-tier framework of "regulated buildings" for existing, occupied buildings with two or more residential units, and the thresholds sit well below England's 18-metre, 7-storey Higher-Risk Building line:
| Category | Height / Storeys | Structural Safety Duty? |
|---|---|---|
| Category 1 | 18m+ or 7+ storeys | Yes — plus registration, safety case report & BAC-equivalent |
| Category 2 | 11–18m or 5–7 storeys | Yes — plus registration |
| Category 3 | Below 11m or under 5 storeys | Lighter-touch duties, but still a regulated building |
Every category carries baseline duties — an appointed accountable person, a golden thread of building safety information, and an annual fire safety risk assessment by a competent person. But Category 1 and Category 2 buildings both carry an explicit duty to address structural safety risk, not just fire safety. That means the effective threshold for structural risk assessment obligations in Wales can be as low as 11 metres or 5 storeys — a building that would never be a Higher-Risk Building under the English regime.
In practice: a 6-storey residential block in Cardiff or Swansea that falls well outside England's HRB definition can still be a Category 2 regulated building in Wales, with a legal duty to assess structural safety risk and register with a Building Safety Authority.
Senedd Research estimates put the numbers at around 180 Category 1 buildings, 449 Category 2 buildings, and more than 51,000 Category 3 buildings across Wales — a very different scale to England's much smaller pool of the tallest buildings.
Structural Risk Assessment Duties: Category 1 vs Category 2
It's worth being precise about what "structural safety duty" actually means for each category, because the two are not identical. Both Category 1 and Category 2 buildings need a genuine structural risk assessment — the underlying engineering work doesn't get lighter just because a building sits in the lower category. What changes between the two is the compliance paperwork built on top of it.
| Requirement | Category 1 | Category 2 |
|---|---|---|
| Structural risk assessment | Required | Required |
| Annual fire risk assessment | Required | Required |
| Registration with a Building Safety Authority | Required | Required |
| Full Safety Case Report | Required | Not required |
| Building Safety Certificate (Wales' BAC equivalent) | Required | Not required |
| Resident engagement strategy | Required | Not required |
| Complaints investigation system | Required | Not required |
In other words: Category 1 buildings carry the full weight of the Welsh regime — structural and fire risk assessment, registration, a Safety Case Report, a Building Safety Certificate, resident engagement, and a complaints system, closely mirroring what Category 1 (England-equivalent HRB) duties look like under the BSA 2022. Category 2 buildings carry a genuinely lighter compliance wrapper — no certificate or Safety Case Report to produce — but the structural risk assessment itself is not optional and not a lesser version of the same exercise. A building owner shouldn't assume that "Category 2" means "structural risk doesn't really apply here"; it means the certification burden is lower, not the engineering standard.
Why This Matters for Portfolio Owners and Managing Agents
If you own or manage buildings on both sides of the border, you can't apply a single test. A building that clears England's HRB threshold comfortably might still need separate consideration in Wales at a lower height, and vice versa for the construction-phase residential-unit difference. Portfolio-wide compliance reviews need to run the Welsh categorisation test independently, not assume the English outcome carries over.
Where Things Currently Stand
This is a genuinely live area of regulation, not a settled one. The Building Safety (Wales) Bill was passed by the Senedd on 10 March 2026, and construction-phase regulations for Wales came into force on 1 July 2026. The detailed implementing regulations for the occupation-phase regime — covering matters such as remediation orders, leaseholder liability limits, and how building height and storeys are calculated — were out for Welsh Government consultation from 15 June to 7 September 2026. Treat this guide as a snapshot, and check current Welsh Government guidance for the latest position before relying on specific dates or figures.
We Track the Welsh Regime Directly, Not as an Afterthought
Wales is a genuinely emerging market for building safety compliance, and a lot of generalist advice out there is written for England and only loosely adapted. We work across both jurisdictions and apply the correct categorisation test for Welsh buildings from the outset — including the lower height and storey thresholds that catch buildings England's rules would miss.
Own or Manage a Building in Wales?
We carry out structural risk assessments for regulated buildings across Wales, at the correct scope for their category — not a one-size-fits-all England template.
Get In TouchFrequently Asked Questions
Does the Building Safety Act apply in Wales?
Yes, but not in exactly the same form as England. Wales has its own secondary legislation implementing the Building Safety Act 2022 for buildings under design and construction, and has gone further with its own standalone legislation, the Building Safety (Wales) Act 2026, covering existing occupied buildings — a regime that does not have a direct equivalent in England.
What height of building needs a structural risk assessment in Wales?
Under the Building Safety (Wales) Act 2026's tiered framework, both Category 1 buildings (18 metres or 7+ storeys) and Category 2 buildings (11 to 18 metres or 5 to 7 storeys) are required to address structural safety risk, not just fire safety. That means the practical threshold for structural risk obligations in Wales can be as low as 11 metres or 5 storeys — well below England's 18-metre, 7-storey Higher-Risk Building threshold.
Is Wales' building safety regime the same as England's?
No. Both stem from lessons following the Grenfell Tower Inquiry, but Wales has taken its own legislative path, with a lower residential-unit threshold for Higher-Risk Buildings during construction, Welsh local authorities acting as the building control authority rather than a centralised regulator, and a broader three-tier framework covering many more existing buildings during occupation than England's regime does.
How many buildings in Wales are affected by the new regime?
Estimates reported by Senedd Research suggest around 180 Category 1 buildings, around 449 Category 2 buildings, and more than 51,000 Category 3 buildings across Wales — a considerably wider net than the Higher-Risk Building regime in England, which applies to a much smaller number of the tallest buildings.