Hello Help Desk,
I am considering buying this brand new house. It's a good size house. The builder has told me that there are two furnaces for the house, one is located in the attic and the other is in the crawl space. The water heater is also in the crawl space.
I am assuming that these locations do meet codes. Even so, are these good places (attic and crawl space) for these equipment (furnace and water heater)? What are the concerns, if any?
Thanks.

If I were considering buying a brand new home now days I would have a ON SITE inspection by a totally independent inspector. The reason is builders right now are in a big money bind and under those conditions all kinds of nasty stuff can go on.

Now for your questions

Both locations are OK as far as code goes as long as they were installed according to the manufactures instructions and all codes relevant to there locations. In other words I am not there to see the install so I cannot tell if they are installed properly.

Both areas are a pain to work in especially for service work when needed.
The attic area unless properly installed can have water problems through the ceiling from A/C condensate and too much insulation piled around the unit can cause clogs in the drain pan if using blown in insulation. There is also a attic access rule for a walk space,service deck,and lighting with a switch at the entrance so the area is safe to work in without falling through the ceiling. A power outlet is also required.

In a crawl space water leaks can happen and not be discovered until damage is done to the space and the equipment. Same rules for a clear area for service and a light with a switch at the entrance for service. A ground fault power outlet is also a requirement.

There are more rules but I am not going to type the code book. Get the inspection I talked about. Better to spend some extra money for a quality whole house inspection now that hire a lawyer and go to court later. Also take a drive to the county/city building department and request to see all documents from the permit process and all inspection reports. You might be surprised what that folder contains. Good luck.

Just because it is new construction, don't assume everything was done right.

Recently, a good friend purchased a new town house. I discovered the furnace and hot water tank were both venting outside underneath a deck - a big no-no in my snowy area. The builder agreed to fix the furnace, but not hot water tank until we recited the exact page from the Rheem manual that said he was dead wrong. This happened because the builder had the town complete all inspections prior to putting on the deck.

I second what hvac1000 is saying. Get someone that does picky home inspections and make your purchase conditional upon successful passage and addressing of all issues. In my area that has become standard for existing home sales. It personally saved me a bundle by helping me back out of a bad deal 10 years ago.

Preferably you'll want experts in all areas such as HVAC, electrical, plumbing, roofing, carpentry, etc. but the parade of people and cost to you would not make sense. So find a reputable, picky and knowledgeable home inspector, and do the inspection with this individual so there will be no misunderstandings. As part of the service you should get a comprehensive and formal report.

Ask the inspector to pay careful attention to this or any other concerns you have during the inspection.