The HVAC rough-in is an important part of constructing your home, and normally follows the plumbing rough. The HVAC contractor should have stopped by the job when the plumber started to go over his thoughts on how he was planning to run his duct work. This will help the two trades coordinate their work so it’s a win for everyone.
Before you start you should have decided the type and specifications of the system you are buying. This is done during the planning/budget stage of your home. There are many levels of HVAC equipment from the very basic cooling equipment having a single stage compressor, and single speed fan and a low EER rating.
This system will be the least expensive, while being the most expensive to operate and the noisiest. You can go from this type system all the way up to conventional units with dual stage compressor and variable speed fans, up to Geo thermal systems. You need to have a complete understanding of these different types as it will affect the efficiency and comfort of your home for a long time. This is an area you need to be very careful with, as most “spec” built homes and a lot of “custom” built home builders will specific the lower cost units to try to keep the overall cost down. You need to be concerned with all aspects of cost of your HVAC (initial and long term).
Doing your homework in advance will ensure that you get the right equipment—and the right results—for your HVAC rough-in.