Guidance, Document

The Building etc. (Amendment) (Wales) Regulations 2026 (WGC 003/2026)

The purpose of this Circular is to draw attention to regulations that introduce the new 2026 energy efficiency amendments to the Building Regulations, and also amendments to existing legislation in line with the reform of building control processes and to correct errors in recent legislation.

First published: 6 March 2026

Last updated: 6 March 2026

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Building regulations circular

Circular number: WGC 003/2026

Date issued: 6 March 2026

Status: For information

Title: The Building etc. (Amendment) (Wales) Regulations 2026

Issued by: Paul Keepins - Building Standards Technical Manager

Addressed to:

Local Authority Chief Executives
Welsh Local Government Association
Local Authority Building Control
Association of Building Control Approvers
Construction Industry Council
Competent Persons Forum

Please forward to:

Local Authority Building Control Officers
Members of the Senedd

Summary:

For further information contact:

Building Regulations Team
Welsh Government Offices
Cathays Park
Cardiff
CF10 3NQ

Direct line: 0300 060 4400
E-mail: enquiries.brconstruction@gov.wales
Website: building and planning

Introduction

I am directed by the Welsh Ministers to draw your attention to the changes introduced by the Building etc. (Amendment) (Wales) Regulations 2026.
These Regulations make amendments in relation to Part L of Schedule 1 to the Building Regulations 2010 and the implementation of the Building Safety Act 2022.

Scope

The Regulations apply to buildings and building work in Wales.

Amendments in relation to the Building Regulations 2010

Amendments in relation to Part L of Schedule 1 to the Building Regulations 2010 (regulation 3 and related transitional provisions) come into force on 4 March 2027.
Regulation 3 makes changes to the Building Regulations 2010 to:

amend the definition of “fixed building services” to include fixed lifts, escalators or moving walkways in new buildings (but not in individual dwellings),
revoke two regulations related to nearly zero energy buildings and consideration of high efficiency systems which are now deemed redundant due to the uplift in energy efficiency standards,
provide for a new way of measuring energy efficiency, using a new performance metric,
amend the Part L title (conservation of fuel and power) to recognise the requirements also reduce greenhouse gas emissions, and
provide a new requirement within Part L so that when a dwelling or a building containing a dwelling is erected, a system for renewable electricity generation must be installed on-site.

Amendments to Approved Documents L1, L2 and F1

Approved Documents provide practical guidance on ways of complying with the technical requirements of the Building Regulations.
Amendments will be made to the following Approved Documents, which will be available on the Welsh Government website in spring/summer 2026:

Approved Document L: volume 1 (Conservation of fuel and power, and the reduction of greenhouse gas emissions)
Approved Document L: volume 2 (Conservation of fuel and power, and the reduction of greenhouse gas emissions)
Approved Document F: volume 1 (Ventilation)

The amendments to the above Approved Documents will be subject to a separate circular when published.

Amendments in relation to the implementation of the Building Safety Act 2022

Amendments in relation to the implementation of the Building Safety Act 2022 (regulations 4, 5, 6, and 7 and related transitional provisions) come into force on 1 July 2026.
Regulations 4 and 5(3) amend the Building Regulations 2010 and the Building (Registered Building Control Approvers etc.) (Wales) Regulations 2024 to ensure that notifications for work reverted to a local authority are captured in the same way as notifications for standard work.
Regulation 5(2) inserts definitions for terms related to dutyholders into the Building (Registered Building Control Approvers etc.) (Wales) Regulations 2024 to ensure they hold the same meaning as in the Building Regulations 2010.
Regulation 5(4) makes amendments so that a person submitting an Initial Notice is required to inform the local authority that they have previously received a contravention notice in relation to the work that was not remedied, and give details of the contravention, as part of the prescribed form.
Regulation 5(5) also introduces corresponding provisions to give additional grounds for local authorities to reject an Initial Notice if the applicant has previously received a contravention notice and failed to address it.
These amendments are intended to stop individuals from avoiding enforcement by switching RBCA after receiving a contravention notice.
Regulation 6 amends the Building (Restricted Activities and Functions) (Wales) Regulations 2024 to ensure that the checking of plans for higher-risk buildings remains a restricted activity when the new regime for higher-risk buildings comes into force on 1 July 2026.
Regulation 7 amends regulation 20 of the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025 to ensure the transitional arrangements in relation to changes to building control processes from 1 July 2026 function as intended for work overseen by Registered Building Control Approvers.
Our intention for transitional provisions for both the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025 and the new higher-risk building work regime introduced by the Building (Higher-Risk Buildings Procedures) (Wales) Regulations 2025 is that the changes will not apply to work where building control approval has been sought before 1 July 2026.
Therefore, if plans for building work have been deposited before 1 July 2026, or an initial notice or building notice has been given for building work before 1 July 2026, that building work will continue under the existing building regulations. This means that new requirements including the new higher-risk building work regime, dutyholder requirements, and new notifications to Registered Building Control Approvers and Local Authorities will not apply to that work.

Transitional provisions

The amendments made in regulation 3 in relation to the energy efficiency requirements of the Building Regulations 2010, do not apply to building work that has commenced or if certain notifications have been made in relation to the work, to make sure that work which is already in progress can be completed without major disruption. These Regulations and new Approved Documents do not apply in relation to building work on a particular building where the building work has been started in accordance with a relevant notification provision, provided that the building work on that building has already commenced or is started within 12 months of these Regulations coming into force.
In some cases, applications will be in respect of a number of buildings on a site, for example a number of houses. In such cases, it is only those individual buildings for which work is commenced which can take advantage of the transitional provisions.
Amendments made in regulation 5, in relation to completion notices for reverted work, dutyholder definitions and contravention notices, will not apply to initial notices cancelled before the regulations come into force. This is to avoid circumstances where a person may inadvertently not comply with these provisions due to the timing of cancelling an Initial Notice.
Annex A to this circular sets out in tabular form all the changes to the Building Regulations.

Further information

Stakeholders are encouraged to familiarise themselves with the changes being introduced.
The regulations can be accessed on the following web link: The Building etc. (Amendment) (Wales) Regulations 2026
The full Explanatory Memorandum is available on the Senedd Website: SL(6)790 - The Building etc. (Amendment) (Wales) Regulations 2026

Enquiries

Any enquiries on this Circular Letter should be addressed to:

Mark Tambini
Building Regulations
Welsh Government
Rhydycar
Merthyr Tydfil
CF48 1UZ

E mail: enquiries.brconstruction@gov.wales

Yours faithfully,
Mark Tambini
Head of Building Regulations Policy

Annex A

The following table lists all the changes made by S.I. 2026 No. 60 in relation to Part L of Schedule 1 to the Building Regulations 2010 (regulation 3 and related transitional provisions):

S.I. 2010/2214 Regulation No.	S.I. 2026 No. 60 Regulation No.	Action
2(1)	3(1)	Regulation 3(1) amends the definition of “fixed building services” to include fixed lifts, escalators or moving walkways in new buildings (but not in individual dwellings).
25A	3(2)	Regulation 3(2) revokes regulation 25A (consideration of high-efficiency alternative systems for new buildings).
25B	3(2)	Regulation 3(2) revokes regulation 25B (nearly zero-energy requirements for new buildings).
25D	3(3)	Regulation 3(3) amends regulations to apply an updated performance metric for dwellings to be measured against. References to “energy efficiency rating” have been replaced by “energy use intensity rating”.
26C	3(4)	Regulation 3(4) amends regulations to apply an updated performance metric for dwellings to be measured against. References to “energy efficiency rating” have been replaced by “energy use intensity rating”.
27C	3(5)	Regulation 3(5) amends regulations to apply an updated performance metric for dwellings to be measured against. References to “energy efficiency rating” have been replaced by “energy use intensity rating”.
Schedule 1 Part L (Requirements)	3(6)	Regulation 3(6) amends Schedule 1 to add provision for the reduction of greenhouse gas emissions and insets a new requirement so that when a dwelling or a building containing a dwelling is erected, a system for renewable electricity generation must be installed on-site, subject to specified limitations.
n/a	8(1) and (2)	Regulations 8(1) and (2) set out the transitional provisions for the Regulations in relation to the above changes.

The following table lists all the changes made by S.I. 2026 No. 60 to the Building Regulations 2010 in relation to the implementation of the Building Safety Act 2022:

S.I. 2010/2214 Regulation No.	S.I. 2026 No. 60 Regulation No.	Action
17(2)	4(1)	Regulation 4(1) inserts a reference to the new completion notice requirement for work reverted to a local authority inserted by regulation 5 of these Regulations.
41(3)(b)(ii)	4(2)	Regulation 4(2) inserts a reference to the new completion notice requirement for work reverted to a local authority inserted by regulation 5 of these Regulations. Please note, regulation 41(3)(b)(ii) of the Building Regulations 2010 is inserted by the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025.
44(4)(b)	4(3)	Regulation 4(3) inserts a reference to the new completion notice requirement for work reverted to a local authority inserted by regulation 5 of these Regulations. Please note, regulation 44(4)(b) of the Building Regulations 2010 is also amended by the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025.
44ZA(3)(b)	4(4)	Regulation 4(4) inserts a reference to the new completion notice requirement for work reverted to a local authority inserted by regulation 5 of these Regulations. Please note, regulation 44ZA(3)(b) of the Building Regulations 2010 is also amended by the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025.

The following table lists all the changes made by S.I. 2026 No. 60 to the Building (Registered Building Control Approvers etc.) (Wales) Regulations 2024 in relation to the implementation of the Building Safety Act 2022:

S.I. 2024/1268 Regulation No.	S.I. 2026 No. 60 Regulation No.	Action
2	5(2)	Regulation 5(2) inserts definitions for terms related to dutyholder requirements to ensure they hold the same meaning as in the Building Regulations 2010.
17A	5(3)	Regulation 5(3) inserts new regulation 17A into the Building (Registered Building Control Approvers etc.) (Wales) Regulations 2024. This provides for a notice to be given upon completion of work that has reverted to a local authority.
Schedule 1 Form 10(W)	5(4)	Regulation 5(4) inserts a requirement for a person carrying out work that is cancelling an initial notice to state, and give details, if they received a contravention notice in relation to the work and it has not been remedied.
Schedule 2 (grounds for rejecting an initial notice, an amendment notice or a plans certificate combined with an initial notice)	5(5)	Regulation 5(5) provides new grounds for rejection of an initial notice under which a local authority may reject an initial notice where that work was under a previous initial notice, was subject to a contravention notice and the contravention was not remedied.
n/a	8(3)	Regulation 8(3) sets out the transitional provisions for the Regulations in relation to the above changes.

The following table lists all the changes made by S.I. 2026 No. 60 to the Building (Restricted Activities and Functions) (Wales) Regulations 2024 in relation to the implementation of the Building Safety Act 2022:

S.I. 2024/238 Regulation No.	S.I. 2026 No. 60 Regulation No.	Action
3	6(2)	Regulation 6(2) inserts a reference to the Building (Higher-Risk Buildings Procedures) (Wales) Regulations 2025 in provisions relating to the checking of plans for compliance with requirements of the building regulations.

The following table lists all the changes made by S.I. 2026 No. 60 to the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025 in relation to the implementation of the Building Safety Act 2022:

S.I. 2025/1320 Regulation No.	S.I. 2026 No. 60 Regulation No.	Action
20	7(2)	Regulation 7(2) substitutes transitional provisions in relation to changes made to the Building (Registered Building Control Approvers etc.) (Wales) Regulations 2024 by the Building etc. (Amendment) (No. 2) (Wales) Regulations 2025.