Principal Designer and Principal Contractor Declarations When There Is No Architect

Many domestic structural alteration projects proceed without an architect. The homeowner appoints a structural engineer directly and the main contractor manages the build. In this situation, someone must still hold the Principal Designer (PD) and Principal Contractor (PC) dutyholder roles required under the Building Safety Act 2022.

Who Takes These Roles?

Where there is no architect or building designer coordinating the project:

– The main contractor typically takes both the Principal Designer and the Principal Contractor roles
– This is a recognised arrangement under the legislation for smaller domestic projects where a single organisation is effectively controlling both design coordination and construction management

The main contractor must sign the relevant declarations at Building Regulations submission and at completion, confirming that the design and construction have been coordinated in compliance with the regulations.

Scope of the PD Role for the Contractor

The contractor taking the PD role in this context is not responsible for design disciplines outside their scope. A contractor acting as PD for a structural alteration is responsible for:

– Coordinating the structural design information (PorthouseDean’s drawings and calculations)
– Ensuring safe construction methods are planned for structural work
– Providing information to Building Control as required

They cannot take responsibility for design disciplines they are not competent to review — for example, fire strategy, thermal performance design, or drainage design. Where those elements exist on the project, appropriately qualified designers must provide compliant design information, even if the contractor is coordinating it.

PorthouseDean’s Position

PorthouseDean’s scope extends to Part A of the Building Regulations (Structure). PorthouseDean cannot act as Principal Designer for the whole project. On a project without an architect, PorthouseDean provides structural design and calculations — the main contractor (as PD) is responsible for incorporating this into the overall submission and coordinating any other design elements.

If Building Control asks who the Principal Designer is and there is no architect, the main contractor should confirm that they are acting in that capacity with an agreed limited scope.

Contact us if you have questions about how your project team should be structured.