We are building a home and the builder says that LARGE returns vs. multiple returns is the most efficient for the HVAC system. The placement of the return is an eyesore when you enter the front door and I also worry about the efficiency of the system. He said that the three different HVAC companies in the area ALL do the ductwork in that manner. I'm not convinced. I am also worried about the noise with the larger returns.In addition, the ductwork is all flexible ductwork and not sheetmetal. Please advise. They have already installed the returns but the drywall is not in place. We are building a large two story home and on a crawl space which is unfamiliar territory for me. The more I read, the more concerned I am.