Which types of structural framing systems and materials are most commonly used in the US for residences? For office buildings?
Residential structural systems are most often made out of sawn wood and put into wood frames. (Though increasingly plywood and manufactured wood are becoming common place). Commercial and office structural systems are most often made of either concrete or structural steel (or a combination of the two) and put in beam and joist configurations on columns (often with shear walls for lateral forces).
These are the most used materials because they are easy to work with and very cost-effective for their scale. For residential buildings, using wood allows much of the frame to be manufactured off-site, and similar can be said for concrete and steel. For residential uses, the required loads of a building are generally much smaller, so steel and concrete become expensive in comparison to wood. For commercial uses, the converse is true.
Why do different teams of designers and subcontractors link and share their models during the design process?
What are the advantages of linking models?
Are there any disadvantages to linking models?
How do you think design coordination was done before we started using digital models?
I think design coordination was done before this by having a bunch of humans look at the different drawings for the project they were looking at and going room-by-room to see if there were any conflicts. Of course a human could mess this up big time, so there were probably many people looking for conflicts. In addition, I could imagine some numerical formula being used to check that there would be enough room for all the systems in the building, at least theoretically.
Having coordination done digitally is incredibly useful because 1) the computer can detect all the clashes, as the computer is far more comprehensive and accurate in such tedious tasks and 2) the issue can be fixed right in the model instead of trying to redraw the conflict and issue new contract documents. This saves everyone a ton of time (and labor)!
What strategies can design teams use to find and avoid clashes prior to the start of construction?
What can be done besides sharing the models digitally?
At what point in the project development process should design coordination start?
Design Coordination should start at the very beginning of the project, when the key stakeholders come together to discuss what they would like out of the project. This is because each party has information which could aid in making a more efficient, beautiful, and useful building. The owner knows what it wants; the structural engineer knows how to keep buildings standing; the builder knows how to construct things in a timely and cost-effective manner. By consulting other parties early, the factors of design that impact those parties can be considered so that disruptions and conflicts can be minimized. (However, there is some danger to catering too much to other parties' needs; cutting edge architecture often needs to push the boundaries on the other disciplines).
(It's never too early.)