Last edited 04 Sep 2020

Design responsibility matrix

Building design was traditionally carried out by a small team of consultants working for a client, who would complete the design before seeking tenders from contractors to carry out the works. However, as buildings have become more complex, design and construction have begun to overlap, a wide range of specialist designers have emerged, contractors have taken on more of a managerial role, and the whole supply chain has become engaged in the design process. As a result, it is increasingly important to define precisely who is responsible for which part of the design.

A design responsibility matrix (DRM) sets out responsibility for each element of the design at each stage of the design development process and to what level of detail. It might be accompanied by the development of a contractual tree, illustrating the contractual relationship between the participants in the project. It can also be accompanied by a project roles table that sets out the overall roles required for a project.

Preparation of a design responsibility matrix should begin early in the development of the project. It may start with a simple, strategic overview of design responsibility for the main design elements. As the project progresses, however, it should increase in detail to allocate responsibility for specific elements, systems and products, setting out the level of detail and format of design information to be produced and any requirement for collateral warranties.

It is important that design responsibilities are clearly defined and properly understood before tender documentation is prepared or appointments made.

The client may wish to allocate the roles of lead designer and lead consultant to co-ordinate the work of designers. It might also be appropriate to appoint a design co-ordinator (for the co-ordination and integration of design prepared by specialist contractors) and a computer aided design (CAD) and/or building information modelling (BIM) co-ordinator and BIM information manager. Contractors may appoint their own design managers to co-ordinate their own design and that of sub-contractors.

On projects where BIM is adopted, a design responsibility matrix may form part of the Employer's Information Requirements (EIR).

The RIBA Plan of Work 2013 defines the design responsibility matrix as: A matrix that sets out who is responsible for designing each aspect of the project and when. This document sets out the extent of any performance specified design. The Design Responsibility Matrix is created at a strategic level at Stage 1 and fine tuned in response to the Concept Design at the end of Stage 2 in order to ensure that there are no design responsibility ambiguities at Stages 3, 4 and 5.’

The RIBA Plan of Work toolbox provides a pro-forma design responsibility matrix, with each aspect of the design coded according to the Uniclass2 classification system.