Spray foam insulation is by far the most energy efficient as you can increase your R-value for the same space (Typical 2x4 basement fir out would allow R-15 batt, and closer to R-22 with spray). It also has the advantage over a batt insulation of completing filling the space which can be difficult to do around electrical, plumbing, etc. That being said, spray insulation is significantly more expensive than batt insulation or blown in insulations (which can be done in walls as well). In a basement, you have far less energy loss through the walls than on the upper floors that are exposed to the "air". Ultimately, most people have to make the choice based on length of time they will be in home. Can you recoup the additional cost in energy savings over the time frame you plan on staying. Geographical concerns can also play into the choice as if you are in an area with little competition for spray, the price can even be higher. If you are very energy conscious, it may not make a difference how much you pay additional for the added R-value as a measure of your carbon foot print. In my opinion, with proper air infiltration mitigation measures (where a good portion of energy is lost), on a basement, batt or blown fiberglass would be the best value proposition for a basement.

There is nothing wrong with using spray form insulation on basement walls. However if the basement is mostly below ground then foam insulation is a little overkill in my opinion. There is much less heat loss through a basement wall that is below ground versus the walls of your home or attic. Spray foam is very good in stopping air infiltration but basement walls usually don't have this issue.

You should be fine with R-13 batt insulation. If you want extra insulation then for a little more money then build an exterior wall with 2x6 lumber and install R-30 batt insulation.

As for the floor, a carpet with padding should be sufficient. The earth beneath the floor slab is below the frost line. It is not a cold as you think it would be.

When we finished our basement walls I glued 1" thick sheets of Dow Corning Foamular closed cell foam on the walls and taped the seams with Tyvek tape. I then framed my 2x4 walls as the next layer, and filled them with bats of mineral wool insulation. The walls of my basement are about 6-7 feet underground, and they never feel cold.

I also put a thin layer of foam (1/8"?) under the sole plates on the walls, and used pressure treated wood. The rest of the framing was standard pine studs.

We also insulated the rim joist, and then used spray foam for fire blocking at the top of the wall framing. By US building code, the wall stud cavities must be sealed off from the rim joist area so that fire cannot come up through the wall and easily spread out into the area between the joists, so the fire blocking was mandatory.

In most areas, for flooring I just painted the cement floor gray, and then use area rugs and runners to provide a comfortable walking surface. We did initially use ceramic tile in the bath and laundry area, but then decided it was too expensive to use it everywhere.

In the full bath I installed electric floor heating (under the tile) from a company called Warmly Yours, and it works well. When set to about 74-76 degrees it provides a moderately warm surface when you stand in front of the vanity or step out of the shower, but does not really feel like its hot. The electric floor heat is really nice, but would get very expensive for a large area. For the bathroom it cost about $500 for the cork underlayment, electric grid, heat sensor and programmable thermostat.

Bruce

You absolutely should not use fiberglass or other porous insulation to insulate basement walls. Use sheets of rigid foam, covered with light studwork with sheetrock fastened to that. Reasons for avoiding fiberglass batts and similar materials in a basement can be found here:

http://www.greenbuildingadvisor.com/blogs/dept/musings/how-insulate-basement-wall

I think there's a lot of bunk in that post. First off, there's just as much problem with vapor permeation in regular (above ground) framing walls as there is in the basement. In fact, you should have less issues in the ground. The key is to use a properly installed continuous vapor barrier (or use closed cell foam which essentially is its own barrier).

If you have problems with water coming in from the outside, you've got big trouble no matter what form of insulation you use.

I should have stated in my post that the wall framing in a finished basement should not be up against the exterior wall. There needs to be an air gap between the fiberglass insulation and the basement wall. That is how my basement was finished many years ago and I have had no problems.

Ron, there is a difference in moisture movement in above-grade framed walls vs. below-grade concrete foundation walls. In most cases, the ground outside a basement wall is damp and cooler (in summer) than outside a framed wall. In many places, the ground temperature is below the summer air dew point. A porous insulation (eg. fiberglass batt), unless installed to perfection, can let interior air come in contact with that cooler concrete wall, with condensation of humidity. To be sure, there are basements insulated with FG batts that have not experienced significant problems, but there are many more that become musty mold factories. The building science explaining this and showing the right way to insulate a basement is well understood now and easy to find (eg. www.greenbuildingadvisor.com and www.buildingscience.com).

Mike, what do you propose is the function of that air gap between FG insulation and the basement wall?

My basement has a french drain in the floor along the basement floor perimeter. It would be difficult to nail a 2x4 floor plate into the concrete even if you wanted to frame the wall up against the basement wall. But now that I am older and wiser I have come to realize the air gap provides air circulation if you have damp basement walls.

If the basement has high humidity problem then I would want to address that first before installing any type of insulation.

Mike, if you have air circulating through that air gap, then you are bypassing much of the insulation's value. Also, in summer, letting humid air contact a cold foundation wall typically below the dew point of the air just adds to the dampness of the concrete surface. It also supplies dust from the air, more nutrient for mold formation. As described in that greenbuildingadvisor reference I cited, spray foam seals off the concrete surface against air flow and provides a very low permeance vapor retarder layer to keep air humidity from that cold surface. Installing rigid foam board takes care of insulating and diffusion of water vapor from basement air, but the edges must be sealed, perhaps with a bead of canned foam, to prevent air circulation behind the panels of foam.

High humidity in a basement can come from liquid water leaks or simply migration of moisture in the soil through the concrete, which is relatively porous. Water leaks are a problem that must be addressed separately, as you note. Migration of ground moisture can be reduced substantially by applying concrete-sealing treatment, which penetrates the surface and seals the pores. Articles on silane or silicate-based brush-on sealers are easily found.