1) Electric wall or baseboard heaters: Cheap to buy, expensive to operate and can be noisy (like at the rental house).
2) Hot water baseboard heaters: these can be attractive, a bit expensive, and require much hotter water (ca 160-180°F) than we'll be making in the basement (120°F for Warmboard). So that means buying a second water heater (boiler really), and that doesn't make any sense to us.
3) Radiant heating—Staple up. There are various companies that make systems for heating your space by stapling radiant tubing below the subfloor and insulating the joist cavity. The idea is that the heat moves up and through the floor: early versions were simply hot-water tubing attached to the subfloor. Now they prefer to use aluminum plates or sheets to spread the heat out, which works pretty well. The heat source (pipe) is still 1.5" away from your feet, but wood has an R value of 0.7-1.4/inch, so there isn't much resistance. These plates screw to the bottom of the subfloor and provide a track for the tubing. Typical products are include Joist Trak by Wirsbo ($2/sq. ft) and Thermofin C heat transfer panels ($3.50 sq. ft) by Radiant Engineering. The materials are commonly priced at about $6-10 a square foot, which is as much as the clearly superior Warmboard we used downstairs ($215 per 4'x8' sheet = $6.72 sq. ft). One problem with staple up is you need to snake 300 ft of semi-rigid Pex through holes in the floor joists, joist blocking, and any headers. You use 8" spacing, so 300 ft of pipe (max length per loop) only covers 200 sq. ft of floor. Plus all the work is overhead with ladders, which isn't pretty when middle-aged folks are involved.
4) Radiant heating—Above floor. In retrospect, we probably should have used the Warmboard upstairs too since the other (inferior) commercial products are nearly comparable in price. However, we went past that fork in the construction road several months ago and there's no point in looking back (sorry Bruce Hull, our Warmboard guy). Nevertheless, other above-floor options are out there. Two prominent ones are Quik Trak panels by Wirsbo and Raupanels by Rehau. The Quik Trak panels are 7" by 48 and screw down onto the subfloor. They price out at about $4/sq. ft (currently on sale). One problem with these is that they use 5/16" HePex O2-barrier tubing which is not compatible with co-mingled radiant and domestic water system. Same goes for the Raupanels, which are lower tech. The are basically 8" x 48" plywood panels with a groove routered down the middle for the Pex. The ends are pre-routered returns, so when its all laid out and screwed down it looks like a less eloquent version of Warmboard, but priced at about $11/sq. ft. The attractive part about above floor heating is how easy the tubing goes down. So I got thinking about a 4th option, which I like to call Mikey's Thermoboards.
4) Thermoboards (aka poorman's Warmboard). This is a hybrid version of Raupanels made out of 5/8" plywood. Technically, the piping gets laid out just like the Warmboard, but it doesn't have a continuous bonded-aluminum upper face. I'll rip 11 3/8" wide panels out of the 5/8" AC plywood (longways, 4 panels per sheet, ca. $35 each or about $1 sq ft.). The 1/2"AquaPex tubing (5/8" OD, $0.37/ft mail order) will go between the panels, for a finished width of 12" per panel. For the returns, I'll cut 12" x 48" panels from plywood, screw then down and use the router templates and bit that Warmboard supplied to make the return channels for each pipe run. I'll put a layer of aluminum under the panels (heat transmission) where I want it a bit warmer (bathroom) and cover the tubing with 10"-wide aluminum (comes in rolls, like the stuff they extrude gutters from now days). I can staple the aluminum down with my new airgun (Porter Cable from Tool King in Denver; it has a compressor, stapler, finish nailer and brad nailer; $229) and screw the panels in place with 1 1/8" drywall screws (ca. 800). Lots of labor, but like Pete Rowley (ex-USGS) was fond of saying "what is time to a pig." When you install the finished flooring, be careful to not nail through any of the aluminum or piping, and all is well (same goes with the Warmboard). The aluminum runs about $1 a square foot, so I think the finished Thermoboards (without tubing in them) will price out at $2.50 a sq. ft, which is 2/3rds to 1/4th the price of commercial options. Did I mention the No. 1 reason to build your own house: You can easily justify every tool you'd want to buy (new table saw comes next week, oh boy).
By the way, we've got a daytime security system in place. It has high-gain audio capability, search and retrieve options, and the ability to incapacitate intruders. It operates during working hours and is fueled by bacon, treats, and lunch scraps: a pretty efficient unit named Coal. He's Gary's buddy and worksite dog. He grew up on the job and, in fact, Gary has turned down framing jobs for people that aren't particularly fond of dogs.
