The New Principal Designer Role: What You Need to Know

These changes impact all construction projects that require a new Building Regulations application—from domestic house extensions to higher-risk buildings (HRBs). Under the updated rules, every project must now designate two key principal duty holders: the Principal Designer and the Principal Contractor.

Understanding the Role of a Principal Designer

The Principal Designer role was first introduced under the Construction (Design and Management) Regulations 2015 (CDM Regulations). However, the responsibilities outlined under CDM—which fall under the Health and Safety at Work etc. Act 1974—are significantly different from those now required under the Building Regulations. The latter, established under the Building Act 1984 and the Building Safety Act 2022, impose new duties and a broader scope of accountability for compliance with safety standards.

Under CDM, the primary duty of the Principal Designer is:¹ 

‘to plan, manage and monitor the pre-construction phase of a project and to co-ordinate matters relating to health and safety.2 This is to ensure, so far as is reasonably practicable, that construction projects are designed and managed without risks to the health or safety of those who build, use and maintain them.’

Under the Building Regulations¹, the Principal Designer is required to: 

‘plan, manage and monitor the design work during the design phase’3 and to ‘co-ordinate matters relating to the design work comprised in the project so that all reasonable steps are taken to ensure that the design is such that if the building work to which the design relates were built in accordance with that design the building work would be in compliance with all relevant requirements.’4

Compliance Responsibilities of a Principal Designer

The Principal Designer is now responsible for ensuring that all design work complies with:

• Schedule 1 of the Building Regulations 2010, covering a wide range of requirements from Part A (Structure) to Part S (Infrastructure for Electric Vehicle Charging).
• Regulation 7(6), which governs materials and workmanship, ensuring that all materials used are suitable for their intended purpose and perform effectively under the given conditions.

In practice, this means the Principal Designer must take all necessary steps to coordinate the design process and ensure full compliance with Building Regulations. While individual designers remain accountable for their specific contributions, the Principal Designer holds ultimate responsibility for overseeing and integrating all design elements. They must also only accept projects where they possess the skills, knowledge, experience, and behaviours necessary to fulfil their legal duties.

A Principal Designer can be an individual or an organization appointed by the Client.

There’s more…

The Building (Higher-Risk Buildings Procedures) (England) Regulations 20235 introduced new compliance measures for high-risk buildings (HRBs). As part of an HRB Building Control approval application, applicants must now submit a ‘competence declaration’ and a ‘Building Regulations compliance statement’ to demonstrate regulatory adherence. Additionally, the Principal Designer is responsible for maintaining an appropriate frequency of inspections to monitor safety occurrences throughout the construction phase. These changes come with stricter accountability, as the new duty holder faces greater liabilities, tougher sanctions, and increased oversight—reinforcing control over the design process and ensuring safer outcomes.

How can MBH help you 

At MBH we have provided Principal Designer services under the CDM regulations for many years. Integrating the project design with health and safety considerations has been at the forefront of our responsibilities.  

We also offer the Principal Designer services under the Building Safety Act 2022 which integrates the responsibilities of the PD role under CDM regulations along with the new and additional requirements under the new duty holder regime ensuring our projects are safe, energy-efficient, and accessible once completed. 

Our team of experts can help with -

• Integrating the compliance requirements (both legal and regulatory) with the design process
• Early risk identification and mitigation.
• Coordinating design work across multiple disciplines and act as liaison between designers, contractors and regulatory bodies. 
• Collaborate with building control and obtain the required approvals as well as certifications to verify compliance with Building Regulations for all types of projects (including High Risk Buildings).
• Client and Stakeholder engagement, keeping them informed about risks and recommended safety measures.
• Working with Principal Contractors to ensure that safety standards continue into the construction phase. 

If you’d like to discuss your project requirements and how we can help you transform your project, then contact us today for a no-obligation consultation – www.mbhltd.com or email mbh@mbhltd.com.