A couple of posters have mentioned hard water. If this is a new experience for you, I would strongly recommend that you consider installing a water softener. When we built our home, we had to put in a well (our first time with one.) The water was tested for all the usual suspects, except for hardness. It made us weep to see all our beautiful Kohler faucets turn cruddy before our eyes, not to mention taking lousy showers, making lousy coffee, and doing lousy laundry. The softener became a necessity and not a "nice-to-have". Of course, hardness is all relative in that some folks have just a little hardness that can be tolerated okay while others can have very hard water. Yes, it's yet another appliance to maintain, but that hard water negatively affects so many of your home's systems.

floor heat is not hot enough to warm your clothes in the way that was mentioned in the first post. it is ok to warm a closet floor too. There is no danger. when you go see floor heat companies' web sites, you will see that they often place the heat cables in the middle section of the floor and not around the perimeter:: this is one way to plan it out well, so that you are not spending more and not putting heat into furniture (or boxes). BUT, the amount of heat energy is so minimal that it makes no big difference if some of the furniture base is resting on heated sections of floor. However, this statement might be untrue in one case or another, and if so, then the heat will build up a bit more than expected and perhaps cause some form of problem (like, just imagining, e.g. a stronger glue smell coming from cheap furniture). So, the companies are not going to overstate the case and advise you to install heat cables underneath fitted furniture that has closed-box bases.

Since you have chosen warmboard over gypcrete, what was your reasoning behind it besides responsiveness? I am sorry for the confusion. I didn't build a house with Warmboard, I had it in a house where original owner had installed it. It wasn't a house I built. I used it in the sense that I heated the house with it. I looked at the Gypcrete system and somehow feels uneasy about it. Doing a concrete pour over first and second floor does not sound structurally sound to me. Gypcrete has positives and negatives but shouldn't be overlooked because of structurally sound. I think a competent and knowledgeable designer is much more important than which type of system you use. So if you don't have a lot of experienced local people, you have to find experienced people who can help design at a distance. I would start with Radiant Engineering (talk to many companies though). A long somewhat unbiased discussion of radiant: First, it should be noted that radiant heat isn't an efficiency discussion. As people have pointed out many times hydronic radiant systems rarely have a positive payback. They are simply too expensive to install and they never payback if you are installing central air. However, every decision in your house isn't about payback. There are many decisions, such as paint color, cabinet color, cabinet design, many fixtures, etc., that are about your enjoyment of your home. No one has a pool installed because they want it to add value to their house. Radiant fits soundly into that category. Next: A discussion of trade-offs between the different systems. It is important to note that ALL radiant floor systems will provide a comfortable environment to a home that other heating methods struggle to achieve. There are basically five considerations in radiant heat (1) installation costs, (2) operating costs, (3) responsiveness (4) allowable customization and (5) noise (as hot water passes through cold aluminum plates it makes noise). If we look at the different systems we can typically see how they handle each of these things. Warmboard is (1) very expensive to install, (2) it has a low operating cost as it is a warm water system rather than a hot water system, (3) incredibly responsive for radiant heat (able to heat a structure in hours rather than days), (4) low customization and (5) low noise. Underfloor transfer plate systems are (1) moderately expensive to install, (2) low operating costs as they are also warm rather than hot water systems, (3) are somewhat responsive (4) highly customizable and (5) have more expansion noise. Gypcrete overpour is (1) moderately expensive (still cheaper than the two above), (2) have low costs as,they too are warm water systems, (3) not responsive at all, (4) are highly customizable and (5) eliminate almost all noise. Staple up systems are (1) pretty cheap (2) high operating costs as they are a hot water system, (3) not responsive at all, (4) limited customization (they are more limited by physics than design), and (5) are pretty noisy. So looking at Warmboard vs. similar systems - the only real concern from using any aluminum covered plywood system is the noise. Warmboard eliminates expansion noise because of the "special" glue they use to adhere the aluminum to the wood. I can't really tell you how special their glue is, I feel confident they will say super special and their competition will disagree. Warmboard type systems vs. underfloor transfer plate systems - Warmboard is quieter but the loops are not really customizable. Loops are 8" apart with Warmboard, so you can choose not to put warmboard in places but you can't get the loops closer together. With transfer plate systems you can customize the heat of a room by simply moving the loops closer together. This means that you can make the floor right outside the shower warmer than the floor beside the toilet (not many people spend a lot of time standing beside their toilet), but there is more expansion noise. Warmboard is a bit more responsive than transfer plates. Warmboard vs, gypcrete overpour - Gypcrete overpour gives you almost unlimited customization without the noise associated with aluminum transfer plate systems. However, it is not at all responsive. Staple up systems - They are more expensive to operate than any of the above systems but are cheaper to install and easier to maintain. You are not likely to nail through a staple up system with a nice thick transfer plate. Also easier to remodel with staple up systems. TL:DR In the end, if I was ranking a radiant system today - I would probably rank it - underfloor transfer plates > gypcrete > Warmboard. But it is a three way photo finish so it wouldn't take a lot to change the order. Also noisy houses don't bother me at all.

Remember that you can use any hydronic technique like Warm Board for under floor radiant tubing method. You don‘t have to do in-slab if you don’t want to. Nordic air-to-water is another option if you don’t want to do geothermal. The advantage of any Nordic air source heat pump is that there is less equipment outside. That contributes to a longer life cycle and it is ‘local’ for you. I believe the federal government will contribute $5k for geothermal so that covers a lot of the drilling cost. You might also choose a geothermal triple function HP with forced air heating & cooling AND full capacity hot water for radiant heat and DHW production if your budget permits. You didn’t mention any details of your new home as to sizes or floors or your electrical rate. BTW: We have a Nordic geothermal heat pump (Montreal) for almost 20 years. Hasn’t failed yet and I don’t know anyone with a similar size house that heats for le$$! IMPO SR