Interfaces between different design team members are important on any project, whether between different consultants, between consultants and a Tier 1 contractor, or between a Tier 1 contractor and its designer Tier 2 or 3 subcontractors and suppliers. It is the lack of clarity of these interfaces that can often give rise to project problems and disputes.
The design processes described in professional appointments, building contracts, design programmes, and in project execution plans do not always clearly identify the points at which a consultant designer – whether an architect, structural engineer or M&E or otherwise – expects additional detail to be added by the Tier 1 contractor through contributions from its appointed Tier 2 or 3 subcontractors and suppliers.
This situation is complicated further where the appointment of the Tier 1 contractor (and therefore of its Tier 2 or 3 subcontractors and suppliers) is not completed until the project is about to start on site.
The benefit of BIM in demanding greater clarification of interfaces – and possibly influencing the timing of the appointment of the Tier 1 contractor (and its Tier 2 or 3 subcontractors and suppliers) – can help.
BIM can particularly address uncertainty that has arisen on projects where an architect or other design consultant has believed that it can unilaterally delegate some of its design responsibilities to others in the supply chain.
Appointments should be very clear that a design consultant has no authority unilaterally to delegate design responsibilities. Therefore, clear agreement on the matrix of design contributions and their timing through the use of BIM models should be a more effective means of defining and limiting a consultant’s potential liability.
The issue of delegated design responsibility has been subject to some case law guidance on the overall cost of damages claimed should be share between are established. The general principle is that the contributions should be “just and equitable” with regard to the extent of that person’s responsibility for the damage caused.
Such terms are by their nature vague and uncertain, and therefore unhelpful to commercial enterprises that seek to properly enter into business relationships with known risks for a known reward. So it is better, then, to use a BIM protocol – whether the CIC’s or otherwise – and its model production and delivery table to clearly establish any delegation of responsibility for design.
By Assad Maqbool, a partner at Trowers & Hamlins specialising in projects and construction
