Changes to the Building Regulations in Wales 2026

Important information for clients, designers, contractors and homeowners

What has changed?

The Welsh Government has published amendments to the Building Regulations, which will apply to all Building Control applications from 1st July 2026. These changes continue the implementation of Part 3 of the Building Safety Act 2022 in Wales and form part of a wider programme to improve building safety. They strengthen the building control system by clarifying the roles, responsibilities and accountabilities of Clients, Designers and Contractors. The Building Safety Regulator continues to regulate Registered Building Inspectors and Registered Building Control Approvers, while Local Authority functions in Wales remain outside its remit.

Please note that all new applications submitted after 1st July 2026 must comply with the new duty holder requirements. These requirements are outlined further within this document.

Registered Building Control Approvers

Businesses that carry out building control work had to register by 6 April 2024 to operate as a Registered Building Control Approver (RBCA). Cook Brown Building Control have been a Registered Building Control Approvers since this date and are licensed by the Building Safety Regulator (BSR) to provide Building Regulation approvals for construction projects in both England and Wales.

Registration as an RBCA replaces the Approved Inspector register run by CICAIR.

Registered Building Inspectors

Building control is to become a regulated profession, meaning that the job title ‘Building Inspector’ will be protected in law. There is a requirement for certain qualifications or experience to be held by individuals working within the profession and for them to register with the regulator (BSR) as Registered Building Inspectors (RBIs). This became a requirement from April 2024 and applies to individuals within Local Authorities and those working for Registered Building Control Approvers.

Duty Holders

The regulations set out duty holder roles for persons and organisations who undertake any building work to which the building regulations apply, these are:

  • Client
  • Principal Designer
  • Designers
  • Principal Contractor
  • Contractors

The roles are modelled on those within CDM regulations and are already embedded in the construction industry. However, these duty holder roles now extend beyond Health and Safety and into Building Regulation compliance as well as setting out roles and responsibilities that also cover residential domestic building projects.

Client

Your duties and responsibilities include but are not limited to the following at Building Regulation application stage;

  • Ensure suitable arrangements exist to plan, manage and monitor the building work to ensure compliance with the Building Regulations throughout the life of the project.
  • Take all reasonable steps to ensure any designers or contractors appointed are competent to carry out the work for which they are appointed. In practice, this means appointing the right people (with the right competencies) for the work.
  • Notify Cook Brown when you appoint a Principal Designer and Principal Contractor with the following information;
    • Name, address, telephone number and email of these
    • Details of any change in the duty holders and the dates of their
    • A signed statement of authority that the information is, to the best of your knowledge,
  • Regulation 11T allows domestic clients to perform the duties of PD and PC where they are deemed competent.
  • Confirm your intended start date and ensure that we are able to submit an initial notice at least 2 days before works are due to start.
  • The date and description of ‘commencement’ or meaningful start will be required at application For new buildings and extensions this would usually be the date at which the foundations and ground floor structure is complete or for other works a date and description of when it reaches the point at which the project requires building control input, see further down for more information regarding this.
  • The client and design team must submit a design that they are confident complies with the building Limited or speculative design information could give rise to Building Control Bodies questioning the competence of designers.

DURING THE CONSTRUCTION STAGE;

  • Any changes to the duty holder roles must be notified to Cook Brown Building Control to inform us of the changes and any new contact details.
  • Cook Brown will inspect the works at certain stages and you must notify us in advance of these stages in order to allow us to inspect the works.
  • Regular monitoring of works to ensure compliance with the Building Regulations, maintaining adherence to designs, and checking the quality and performance of materials is the responsibility of duty holders. Independent checks should be considered during the course of the works, this is not the function of Building Control who will inspect a sample of work at key stages.

WHEN THE WORK IS COMPLETE;

Each duty holder involved in the construction phase must provide compliance declarations to Cook Brown Building Control to confirm that they have fulfilled their duties and confirm to the best of their knowledge that the works comply with the Building Regulations. The declaration must contain the following information;

  • The Client’s name, address, telephone number and email address
  • The Principal Designer and Principal Contractor names, addresses, telephone numbers and email address
  • A statement that the building work is complete
  • A signed statement that, to the best of your knowledge, the building work complies with the building regulations
  • A signed statement from each Principal Designer and Principal Contractor that they have fulfilled their duties under the building regulations

Cook Brown Building Control cannot issue its final certificate without receiving these declarations, as the Final Certificate requires the Approved Inspector to declare that they have received these signed statements.

Regulation 38 requires information relating to Fire Safety to be passed on to the ‘Responsible Person’ at the end of a project on all buildings to which the Regulatory Reform (Fire Safety) Order 2005 applies.

A final inspection should be arranged when duty holders are satisfied that the works are complete and comply with the building regulations. All necessary commissioning certificates and test results should be submitted as soon as practicable to Cook Brown Building Control.

Domestic Client

YOU MUST:

  • Ensure suitable arrangements exist to plan, manage and monitor the building work to ensure compliance with the Building Regulations
  • Ensure that these arrangements are maintained throughout the life of the project
  • Take all reasonable steps to ensure any designers or contractors appointed are competent to carry out the work for which they are appointed

However:

  • The Principal Contractor or contractor must carry out these duties, unless:
  • The Client agrees that the Principal Designer can carry out these duties or undertakes them themselves (Regulation 11T)

 

Principal Designer

Is usually the lead designer and is appointed under Regulation 11U (principal designer and principal contractor) to perform the duties of a Principal Designer.

YOU MUST:

  • Perform all the functions listed within the Designer role below, and,

IN ADDITION, YOU MUST:

  • Plan, Manage and Monitor the design work during the design phase
  • Coordinate all matters relating to design work to ensure that it will comply with the Building Regulations if building work is carried out
  • Ensure duty holder cooperation
  • Ensure all designers comply with their duties
  • Liaise with the Principal Contractor
  • Have regard to comments from the Principal Contractor about compliance with the Building Regulations
  • Assist the Client in providing information to designers
  • Review the arrangements of any previous Principal Designer
  • Notify Building Control in writing, where applicable, that the work is being carried out on behalf of a Domestic Client
  • Where applicable, sign the declarations as referred to above in the Client’s duties when work is complete

Designer

Means anyone (including the Client, contractor or anyone else) who, during their business, carries out design work or arranges for or instructs anyone under their control to do so.

You must:

  • Plan, manage and monitor design work so that if the building work were carried out, it would comply with the Building Regulations
  • Cooperate with the Client, designers, and contractors to the extent that if the building work were carried out, it would comply with the Building Regulations
  • Not start any design work unless you are satisfied that the Client is aware of the duties owed by the Client
  • Carry out design to ensure that if building work were carried out, the design it would comply with the Building Regulations
  • Provide sufficient information about the building’s design, construction and maintenance to allow the Client, other designers and contractors to comply with the Building Regulations
  • Consider any other design work and report any compliance concerns relating to the design compliance to the Principal Designers and Client
  • Must advise the Principal Designer or the Client whether any work they are designing is Higher-Risk building work

 

Principal Contractor

Is usually the main contractor and is appointed under Regulation 11U (principal designer and principal contractor) to perform the duties of a Principal Contractor where there is more than one contractor.

YOU MUST:

  • Plan, Manage and Monitor the building work during the construction phase.
  • Coordinate matters relating to building work to ensure the building work complies with the Building Regulations.
  • Ensure cooperation amongst all duty holders.
  • Ensure all building work is coordinated so that it complies with the Building Regulations.
  • Ensure contractors comply with their duties.
  • Liaise with the Principal Designer as required.
  • Have regard to comments from the Principal Designer concerning compliance with the Building Regulations.
  • Assist the Client in providing information to contractors.
  • Review the arrangements of any previous Principal Contractor.
  • Notify Building Control in writing, where applicable, that the work is being carried out on behalf of a Domestic Client.
  • Sign the declarations as referred to above in the Client’s duties when work is complete.

Contractor

Is any person (including the Client, but not a domestic client) who, in the course of a business, carries out, manages or controls any building work.

YOU MUST:

  • Plan, manage and monitor the building work so as to comply with the Building Regulations
  • Cooperate with the Client, designers and contractors to the extent necessary to ensure that it would comply with the Building Regulations
  • Not start any building work unless they are satisfied that the Client is aware of the duties owed by their duties
  • Ensure the building work they are carrying out complies with the Building Regulations
  • Provide each worker under their control with appropriate supervision, information and instruction to ensure the building work complies with the Building Regulations
  • Provide sufficient information about the work to allow the Client, other designers and contractors to comply with the Building Regulations.
  • Consider other building works when you are only carrying out part of the building work and report any concerns relating to compliance to the Principal Contractor
  • Provide advice to the Principal Contractor or the Client on whether any work is Higher-Risk building work

What is deemed the commencement of work?

Notice before starting work and notice when work is deemed “commenced.”

To serve the Initial Notice, the client must advise the Registered Building Control Approver of the date when it is proposed that sufficient work will have been carried out to deem the work as “commenced”.

Where work does not involve foundation or substructure works, the client must state when the project requires Building Control input.

Work being deemed as commenced is,

  • For the construction of a complex building,
    • Work is to be regarded as commenced in relation to that building or first stage of the building work for that building when the foundations supporting the building and the structure of the lowest floor of that building (but not the other buildings or structures to be supported by those foundations) are completed.
  • Where the work consists of the construction of the building and Complex Buildings does not apply, or horizontal extensions of a building
    • Work is to be regarded as commenced when the sub-surface of structure of the building or extension including all foundations, any basement level (if any) and the structure of ground floor level is completed.
  • Where the work consists of any other building work, and that work will be incorporated into the completed building, then the work is to be regarded as commenced when –
    • It reaches the point at which the project requires building control input, and
    • Without such building control input, at that point, there would be grounds for enforcement.

Notice before starting work and further notice when work is “commenced” etc.

13A.—(1) At least two working days before the day on which building work starts, the person carrying out the work must give a notice to the approver shown the initial notice relating to the building work setting out their intention to start the work and the date that work is to start.

(2) Not more than 5 working days after the day on which the work is to be regarded as commenced the person carrying out the work must give a notice to that effect to the approver.

After three years:

After three years, the Initial Notice will automatically cease to have effect unless sufficient work (as above) has been carried out to deem the project commenced AND the client has given written notice to the Registered Building Control Approver.

Higher-Risk Buildings

From 1st July 2026, Building Control for alterations to existing, or the design and construction of new Higher-Risk Buildings (HRBs), will now have to be taken through the gateway process directly via the Local Authority.

  • New Gateway Processes
    • Gateway One – Stage considerations relating to fire safety and building safety information
    • Gateway Two – Preconstruction Approval before work can commence
    • Gateway Three – Completion approval prior to occupation

HRBs are defined as buildings with 7 or more storeys or have a storey height of 18m or higher and contain either at least one residential unit, or, during design and construction, are a hospital or care home. HRBs are defined in detail within the Higher-Risk Buildings Regulations 2025. Additional guidance on determining if a building is a HRB has been published by the Government.

On 1 July 2026   /   Technical Updates