Has Your Designer Spoken to You About the New Building Regulations Principal Designer Role?

Understanding Your Responsibilities Under the Building Safety Act

The construction industry has undergone its biggest regulatory change in decades.

In October 2023, new Building Regulations came into force, introducing the statutory roles of the Building Regulations Principal Designer and Building Regulations Principal Contractor. These changes are intended to improve building safety, raise standards across the industry and ensure that everyone involved in a construction project understands their legal responsibilities.

Despite these significant changes, many homeowners, developers and commercial clients remain unaware that they now have legal duties when undertaking building work.

What Changed?

The Building Safety Act and associated amendments to the Building Regulations introduced new dutyholder roles for most building projects that require Building Regulations approval.

These regulations place legal responsibilities on:

• Clients

• Designers

• Contractors

• Building Regulations Principal Designers

• Building Regulations Principal Contractors

The aim is simple: ensure that buildings are designed and constructed safely, with compliance considered from the earliest stages of a project through to completion.

What Does This Mean for Clients?

If you are planning:

• A new home

• A house extension

• A loft conversion

• A renovation

• Commercial alterations

• A change of use

• A new commercial development

you have legal responsibilities under the Building Regulations.

As a client, you must appoint organisations and individuals who have the appropriate skills, knowledge, experience and behaviours to undertake the work.

Choosing the right design and construction team is no longer simply best practice—it is a legal requirement.

What Is a Building Regulations Principal Designer?

The Building Regulations Principal Designer is responsible for planning, managing and monitoring the design work during the pre-construction phase to ensure Building Regulations compliance is properly coordinated.

Their role includes:

• Coordinating the design team

• Identifying and managing Building Regulations risks

• Ensuring compliance is considered throughout the design process

• Coordinating information between consultants and contractors

• Supporting the client in meeting their legal duties

• Maintaining the “golden thread” of design information where required

It is important to note that this role is separate from the CDM Principal Designer, although suitably competent organisations may undertake both appointments.

Why Is This Important?

Construction projects are becoming increasingly complex.

Without effective coordination during the design stage, projects can suffer from:

• Design conflicts

• Delays on site

• Increased construction costs

• Non-compliant building work

• Difficulties obtaining Building Control approval

• Expensive remedial works after construction has started

Engaging an experienced Building Regulations Principal Designer early helps minimise these risks and provides confidence that compliance has been considered from day one.

How TMDP LLP Can Help

At TMDP LLP, we provide Building Regulations Principal Designer services across domestic, commercial and heritage projects.

Our multidisciplinary approach combines expertise in:

• Architecture and Building Design

• Building Surveying

• Project Management

• Historic Buildings and Heritage Consultancy

• CDM Principal Designer Services

• Building Regulations Compliance

• Contract Administration

By bringing these disciplines together, we help clients navigate increasingly complex legislation while delivering practical, compliant and commercially focused design solutions.

Whether you’re planning a simple home extension or a complex commercial development, we work with you and your wider project team to ensure compliance is embedded throughout the design process—not treated as an afterthought.