Structural and Services Coordination
What you must know
Coordination is about making structure and services fit in the same three-dimensional space without compromising either. On the structural side, understand load paths from slab to beam to column to footing, the difference between bearing and non-bearing walls, span-to-depth rules of thumb for beams and slabs, and the purpose of movement joints, transfer structures, and bracing. On the services side, know the main horizontal and vertical distribution zones for mechanical ductwork, plumbing and drainage (including grades and venting), electrical containment, fire services, and communications, and how ceiling plenums and risers are sized. You must also understand penetration rules: what may pass through a structural member, what needs a sleeve, and what needs a structural engineer's approval. Clash detection and services coordination drawings, with their own scale and level of detail, are examinable concepts.
Traps
Questions frequently test whether a penetration is permissible - a small hole in the web of a steel beam is very different from a notch in a timber joist or a chase in a column. Another trap is drainage gradient direction or the misconception that a ceiling void can absorb unlimited services. Watch for answers that route a duct through a transfer beam or that ignore the fire-rating of a penetration seal.
Worked example / rule of thumb
A 150 mm diameter drain at a 1:60 fall drops 150/60 = 2.5 mm per metre, or 25 mm over a 10 m run. Rule of thumb: allow roughly 300–400 mm of ceiling plenum for small services and considerably more where rectangular ducts run; if the plenum is tight, ducts go above beams and pipes below. Always check that a fire-rated element retains its rating after penetration.