Energy code requirements for an old school

[ssn61]

I am working on renovation of HVAC for a school in Dallas, Texas. This school is over 50 years old and walls and roofs have R-Value of 3.87 and 7.54 respectively. If we are just renovating and/or replacing the existing HVAC system, does the energy code require to update the walls' and roofs' insulation?

 

[ssn61]

I wanted to add that classrooms have perimeter unit ventilator with hydronic cooling and heating coils. The piping is in crawl space. I also like to add the following questions:
1. In your opinion, would it be better to keep the same HVAC system? meaning replace these units with new ones or should we completely redesign the system and go with above ceiling air distribution? Please elaborate on your answer.
2. Per new architectural codes and standards, do we need to mechanically ventilate the crawl space?

 

[ChasBean1]

I'd say first post, no. But it could depend on your local codes and AHJ (authority having jurisdiction). I've seen updates in life safety and fire control systems imposed on larger projects but I can't see why anyone would impose a requirement for completely new building insulation when you are already doing right by improving the HVAC.

Second post #1: If it's a public school, they have no money. Nonetheless I'd always first propose keeping the same units. There is nothing wrong with UVs for this application and if their condition is such that a little bit of PM (filters, cleaning, lubricating and stroking dampers) can provide decent operation and enough outdoor air to satisfy the classroom demand, try that route first. If they are in such disrepair so as to need spare parts which are now hard to find, then replacement of systems becomes a better option.

Second post #2: Yes, you do. If you look up on this site (or even search engine) "crawl space ventilation" you might find the requirements. I think I may have stated them years ago here, but they may be different now. I don't have the code nearby..