Making changes to a higher-risk building project

The documents you submitted as part of your building control application are known as the ‘agreed documents’.

You must comply with the agreed documents throughout the build. Any change to these documents are known as a ‘controlled change’. You must:

• manage and assess each change in accordance with your change control plan
• record each change in your change control log

You must tell building control authority before starting any work involving a notifiable change.

Changes that could impact compliance with building regulations are known as notifiable changes. Notifiable changes are changes to:

• the construction control plan
• the change control plan
• the layout or dimensions within an individual residential unit
• the number or dimensions of any openings in a wall, ceiling or other building element for any pipe, duct or cable
• a wall tie, wall restraint fixing or support system in any wall or proposed wall, excluding external walls, 
• any other change to the fire and emergency file or fire compliance statement
• the partial completion strategy, if you submitted one as part of the building control approval application
• the staged work statement or a subsequent stages statement, when a new building is being constructed in stages

If you replace a product or building element with something that:

• is of the same, or higher specification or class, then it is a recordable change and you must record it in your change control log
• has a different reaction to fire specification, even it is higher, it may be a notifiable change and therefore you must tell the building control authority about it

You must submit a notifiable change to the building control authority before:

• the change is carried out
• any building work related to the change starts

Once you submit the change, you can proceed with the work.

The building control authority may request further information about the change. You do not have to stop building work while you are responding to this request.

You must stop building work related to a notifiable change if the building control authority tells you that you should have applied for a major change instead.

You must get approval from the building control authority before making any major changes.

Major changes undermine the basis by which the project was approved.

A material change of use of any part of the proposed building is classed as a major change. For example, changing units from commercial to residential use.

If you need a partial completion strategy after the application has been approved without one, you must apply for a major change.

Examples of other major changes include changes to:

• the car parking, when part of the proposed building either becomes or stops being a car park
• the external height or width of the building
• the number of storeys, including mezzanine floors
• the number, width or length of staircases or other escape routes including evacuation lifts
• the external walls including a wall tie, wall restraint fixing or support system in the walls
• any part of the active or passive fire safety measures referred to in the fire and emergency file
• the layout or dimensions of the common parts
• a product, if you intend to replace it with one that has a lower reaction to fire specification and performance classification than specified in the building control approval application
• any assumptions made in the design as set out in the building regulations compliance statement
• the number of residential units or commercial units
• the structural design or structural loading of the building

Before carrying out any major change you must:

• stop any building work relating to the proposed change
• submit a major change application and have building control authority approval for the change

You must not carry out a major change or start building work related to it until the work is approved by the building control authority. 

You must tell the building control authority about any:

• change of client, principal designer or principal contractor
• changes in contact details associated with the application, including the email address you use to access the online application

Each building control authority may set its own processes for submitting changes, to learn which is appropriate for your project, you should consult with the building control authority for the area where the building work will happen.

For some changes, you may also need to get planning permission. If you’re not sure, check with your local authority.

The information must be submitted in writing. It must also be signed by the client or someone acting on the client’s behalf. 

For each change, include a brief description of the change and why you consider it to be a notifiable or major change. 

You’ll need to tell the building control authority: 

• why you are making the change, for example, a change of design approach or availability of materials
• all the advice you sought, even if it disagrees with your proposal
• who gave the advice, their occupation and contact details
• which agreed documents the change affects

Submit copies of any updated agreed documents which are affected by the change.

Submit a compliance explanation. This must explain how the building work will comply with all relevant building regulations after the change is made.

To change the client, principal designer or principal contractor, upload the compliance declaration from the outgoing client, principal designer or principal contractor.

If you want to make multiple:

• notifiable changes that are related to each other, you can submit them in one change notification
• major changes that are related to each other, you can submit them in one major change application
• major changes and notifiable changes that are related to each other, you can submit them in one major change application

If changes are not related to each other, you must submit them separately. If you include unrelated changes in a single change notification or application and the local authority rejects one of the changes, then all changes will be rejected.

If a change affects more than one building control approval application, you must submit the change for each building control approval application.

New buildings constructed in stages

For staged building applications, submit separate change notifications or applications for each stage. You must update all affected agreed documents for each of the stages.

Major changes: application decisions

Unless an extension is agreed, the building control authority may take up to 6 weeks to assess major change applications.

You do not need to contact the building control authority while your application is being assessed. The building control authority will contact you if they need any further information.

You must not start building work related to a major change application before it is approved by the building control authority.

When the building control authority receives your major change application, they check to make sure the required information has been submitted. If any information is missing the building control authority may:

• ask you to supply the missing information
• reject your application

An application that contains all the required information is deemed valid, and will progress to the assessment stage.

A validated application does not mean that the application has been approved.

Approved

Building work related to the major change can start as planned.

Approved with requirements

Building work can start as planned on the parts of the major change application approved by the building control authority.

You must not start building work on any parts of the application that are subject to a requirement, until the building control authority is satisfied the requirement has been met.

Examples of requirements are the building control authority telling you to:

• supply additional information, such as providing further plans or details to clarify certain aspects of the application
• supply revised plans to address changes and concerns raised by the building control authority
• delay certain aspects of building work until you can demonstrate specific requirements are met

Rejected

A major change application will be rejected if it shows that the work will not comply with building regulations.

It will also be rejected if it does not:

• have enough detail to demonstrate compliance
• demonstrate effective strategies for managing compliance

You must not start building work related to the major change if the application is rejected.

Request an appeal of an application decision

If you disagree with an application decision you can request an appeal. Details about how to request a review will be included in the decision letter.

Appeals are made to the Welsh Ministers under regulation 47 of the Building (Higher-Risk Buildings Procedures) (Wales) Regulations 2025. If after the appeal you still disagree with the decision, you can appeal to the Magistrates’ Court. 

The charges for requesting to make changes to a higher-risk building project are set out on the Local Authority websites.