Discipline Interfaces

Why Interfaces Matter

Most coordination failures do not happen inside a single discipline. They happen at the seams where two disciplines meet. A discipline interface is any point where a decision, dimension, or responsibility owned by one team depends on a decision, dimension, or responsibility owned by another team. This page breaks interfaces into two groups — physical and informational — and lists the questions to ask at each one.

Physical Interfaces

Physical interfaces are the geometric points where systems share space. Review each of the items below for every shared decision before the model is issued.

• Clearances — Is the minimum distance between systems maintained everywhere, including future maintenance access?
• Access — Can each system be reached for service without dismantling another discipline's work?
• Supports — Who owns the support, and does the supporting structure know the load?
• Openings — Are all penetrations coordinated, sized, and approved by the discipline being penetrated?
• Maintenance zones — Is the space around equipment reserved and labelled in the model?
• Installation sequence — Can the systems be installed in the order shown without rework?

Information Interfaces

Information interfaces are the data points shared between teams. Mismatched data causes more rework than geometry errors because the problem is invisible until a drawing is issued.

• Naming — Do all teams use the same element names and IDs?
• Level references — Is every team referencing the same level for the same floor?
• Room use — Does the room name in the architectural model match the use assumed by MEP and structure?
• Equipment responsibility — Is it clear which discipline owns each piece of equipment in the model?
• Revision status — Can every team see whether they are looking at the latest issued version?
• Decision authority — Is it recorded who is allowed to change each shared parameter?

Reviewing an Interface

For every interface, confirm three things: the value is defined, the owner is named, and the affected reviewers have signed off. An interface with a missing value or an unnamed owner is an open issue — record it before the handoff.