Building systems meet at physical connections, shared spaces and exchanges of information. A discipline can complete its own design while an essential interface remains undecided. Coordination starts by making those boundaries visible rather than assuming they will be resolved during installation.
For each connection, identify the supplying system, the receiving system and the responsible parties. State what must cross the boundary: power, a signal, a physical connection or a control instruction. Include the information needed to demonstrate that the interface works.
Review the consequences of a change on both sides. A revised equipment selection may affect access, electrical demand or controls. The team receiving the change needs enough detail to assess its own work before the revision becomes an installation instruction.
Use coordination meetings to close decisions, not simply to display drawings. An unresolved issue should have an owner, a required answer and a date linked to the delivery sequence. Escalate dependencies that block another discipline.
Carry the agreed interface into commissioning. Installation checks should confirm the physical arrangement, while functional checks establish that the systems interact as intended. A closed drawing comment is not a substitute for evidence from the completed installation.