Common Assessment Standard Version 6: what the changes mean for construction

The Common Assessment Standard (CAS) has become an important part of pre-qualification across the construction industry, providing a consistent approach for organisations to demonstrate their capability and for clients and contractors to assess businesses within their supply chains.

From 1 November 2026, Version 6 of the Common Assessment Standard introduces a number of important updates to the question set, reflecting the latest legislation, guidance and client requirements. The changes cover key areas including Building Safety, competence and Information Security, alongside new mandatory requirements for all companies.

For construction businesses, this is about more than adapting to a revised set of questions. The changes reflect how expectations around supply chain competence and compliance continue to develop and reinforce the importance of businesses being able to demonstrate that they have the right organisational capability, policies and processes in place.

Why the Common Assessment Standard matters

Introduced by Build UK in 2019, the Common Assessment Standard was developed to create a consistent approach to pre-qualification across construction, helping to improve quality standards while reducing duplication. More than 26,000 companies are now certified to the standard, with a growing list of clients and contractors specifying CAS to demonstrate the organisational capability of their supply chains.

This consistency is particularly important in an industry where contractors may work across multiple projects and for different organisations, each with their own responsibilities for managing risk within their supply chains. Once a company has been certified by a Recognised Assessment Body, its data can be shared at no cost with the other Recognised Assessment Bodies, making it visible to more clients and contractors and removing the need to hold multiple CAS certifications.

As legislation, guidance and client requirements develop, however, the standards used to assess organisational capability also need to keep pace. Version 6 is the latest development in that process and introduces several changes that contractors and organisations managing construction supply chains should understand.

Building Safety moves from ‘opt in’ to ‘opt out’

One of the most significant changes in Version 6 relates to the Building Safety section, which will now operate on an‘opt out’ rather than an ‘opt in’ basis. Companies wishing to opt out will need to provide a statement confirming that they do not carry out any building work regulated by the Building Regulations.

This comes as the construction industry continues to respond to the requirements of the Building Safety Act and the wider building safety regime. Build UK states that companies carrying out work under the Building Safety Act can use the Common Assessment Standard to demonstrate that they have the organisational capability to fulfil their dutyholder roles under the Act.

Version 6 also reflects clarification around scaffolding and temporary works. The Building Safety Regulator has confirmed that the requirement to obtain Building Control Approval applies to ‘building work’ as defined by the Building Regulations and that scaffolding and other temporary works are typically excluded from that definition and therefore are not subject to building control. Build UK notes that scaffolding and temporary works are not in scope of the Building Regulations regulating ‘building work’ unless they form part of the structure once complete.

The update should therefore provide greater clarity around which companies are expected to complete the Building Safety section, while ensuring that those undertaking regulated building work can demonstrate the organisational capability expected of them.

Competence becomes relevant to every supplier

Version 6 also changes how competence is addressed within the Common Assessment Standard. The competence-related questions previously contained within the Building Safety section have been moved into the Quality section and must now be completed by all contractors.

This is an important development because it places competence more firmly within the wider assessment of organisational capability, rather than treating it solely as an issue associated with building safety. For businesses, it means being prepared to demonstrate how competence is managed as part of their overall approach to delivering work, irrespective of whether they are required to complete the Building Safety section.

For clients and contractors assessing their supply chains, bringing these questions into the Quality section also means competence information will form part of the assessment for all suppliers completing CAS, supporting a more consistent approach to demonstrating capability across the industry.

Information Security requirements are changing

Information Security is another area affected by Version 6. Previously, companies holding Cyber Essentials Plus could be exempt from completing the Information Security section, but that exemption has now been removed. Under the updated standard, companies will only be exempt from completing the section if they hold ISO 27001 – Information Security Management Systems.

Companies that have previously relied on Cyber Essentials Plus for this exemption will therefore need to be prepared to complete the relevant Information Security questions as part of their assessment against Version 6.

The change is another example of the standard developing alongside current industry requirements and expectations, ensuring the information considered during pre-qualification remains relevant to the way construction businesses and their supply chains operate.

New mandatory requirements for all companies

Version 6 also makes a number of key questions mandatory for all companies, including requirements relating to fraud prevention, having a dedicated person responsible for quality and a Drugs and Alcohol Policy.

At the same time, Build UK has enhanced the guidance accompanying the question set to provide more support for supply chain companies going through the certification process.

Taken together, the changes show the breadth of organisational capability that construction businesses are increasingly expected to demonstrate. While health and safety remains fundamental, effective pre-qualification considers a much wider range of areas that can influence whether an organisation has the appropriate systems and processes in place to deliver work.

What should contractors do to prepare for Version 6?

For contractors, the priority should be understanding where the revised standard affects the information and evidence they need to provide, rather than waiting until their next assessment to identify areas that may require attention.

Particular consideration should be given to the changes around Building Safety, competence and Information Security. Businesses that do not carry out building work regulated by the Building Regulations will need to understand the requirements for opting out of the Building Safety section, while those that have previously relied on Cyber Essentials Plus for an Information Security exemption should be aware that this exemption has been removed under Version 6.

The update also provides an opportunity for businesses to review whether their policies, responsibilities and supporting evidence continue to accurately reflect how they operate. With competence questions now applying to all suppliers and additional requirements becoming mandatory, being prepared means looking beyond the assessment itself and ensuring the evidence provided is current, relevant and representative of the business.

What does Version 6 mean for construction supply chains?

For clients and contractors responsible for selecting and managing suppliers, Version 6 reinforces the role that effective pre-qualification plays in understanding the businesses within their supply chains.

The changes broaden the areas considered consistently through CAS, particularly by requiring all suppliers to answer competence-related questions and updating the requirements relating to Building Safety and Information Security.

More broadly, Version 6 demonstrates why construction pre-qualification cannot remain static. As legislation, guidance and client requirements develop, the way businesses demonstrate their capability must develop with them. A common industry standard provides a consistent framework for doing this, while regular updates help ensure the questions being asked remain relevant to the risks and expectations facing the sector.

CHAS is one of the seven Recognised Assessment Bodies listed by Build UK that can certify companies to the Common Assessment Standard. For contractors preparing for Version 6, understanding the changes now will help ensure they are ready to demonstrate how their business meets the latest requirements.

Find out more about the Common Assessment Standard

If you’re preparing for Common Assessment Standard certification or want to understand how the latest requirements apply to your business, CHAS can help you navigate the assessment process.