Which types of structural framing systems and materials are most commonly used in the US for residences? For office buildings?

What factors determine why these are the most used materials?

I think that reinforced concrete construction is often used for houses instead of steel construction. This is because reinforced concrete construction has higher sound insulation and heat insulation performance.

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? 

What advantages does doing this coordination digitally have over previous methods?

Since architectural designers and structural designers have different expertise, coordination is effective for each to collaborate.

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?

Anyone can see where the error is, and everyone can fix the point, so you can fix the crash before you start construction.

At what point in the project development process should design coordination start? 

Is it ever too early?