Wales Other Welsh Government circulars
Building regulations circular (WGC 001/2019)
Library captured 10 September 2026 · Source updated 29 August 2026
Building Regulations Wales
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Circular
| Circular number: | WGC 001/2019 | Date issued: | DD / 25 | MM / 02 | YYYY 2019 |
| Status: | For information |
|---|---|
| Title: | NEARLY ZERO ENERGY BUILDINGS |
Issued by:
Francois Samuel: Head of Building Regulations
| Addressed to: | Please forward to: |
|---|---|
| Local Authority Chief Executives Welsh Local Government Association Association of Corporate Approved Inspectors Construction Industry Council | Local Authority Building Control Officers Approved Inspectors Assembly Members |
Summary:
The purpose of this letter is to clarify the implementation of the requirements for nearly zero energy buildings for new public buildings, with respect to Regulation 25B of the Building Regulations 2010.
| For further information contact: | |
|---|---|
| Paul Keepins Building Regulations Welsh Government Offices Merthyr Tydfil CF48 1UZ | Direct Line: 03000 628646 E-mail: enquiries.brconstruction@gov.wales http://gov.wales/topics/planning/buildingregs/ Website: |
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Circular
NEARLY ZERO ENERGY BUILDINGS REQUIREMENTS FOR NEW PUBLIC BUILDINGS
Introduction
The purpose of this letter is to clarify the implementation of the requirements for nearly zero energy buildings for new public buildings, with respect to Regulation 25B of the Building Regulations 2010.
Regulation 25B was introduced into the Building Regulations in 2013 to transpose the requirement in the EU Energy Performance of Buildings Directive for new buildings to be nearly zero-energy buildings. This letter sets out guidance for new buildings owned and occupied by public authorities, which were required to be nearly zero energy buildings from 1 January 2019.
Following the existing Building Regulations guidance would be an adequate way to demonstrate compliance with the nearly zero-energy buildings requirement.
Scope
This Circular letter applies to buildings and building work in Wales.
Regulation 25B
Regulation 25B states: ‘Where a building is erected, it must be a nearly zero- energy building’.
For new buildings occupied and owned by public authorities, the coming-into- force date for Regulation 25B is 1 January 2019.
For all other new buildings, the coming-into-force date for Regulation 25B is 31 December 2020.
Compliance with Regulation 25B
The minimum level of compliance with this requirement may be achieved by meeting the Target Emission Rate required under Regulation 26 and the Primary energy consumption rate under regulation 26A.
Those carrying out the work should also undertake an analysis of the technical, environmental and economic feasibility of using high efficiency alternative systems, which include decentralised energy supply systems based on energy from renewable sources and take this into account as required by Regulation 25A.
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#Source page 3
Enquiries:
Any enquiries on this Circular Letter should be addressed to:

Francois Samuel,
Building Regulations,
Welsh Government,
Rhydycar,
Merthyr Tydfil,
CF48 1UZ.
Telephone: 03000 628232.
E mail enquiries.brconstruction@gov.wales
Yours faithfully,
Francois Samuel
Head of Building Regulations