Put 1" extruded polystyrene (XPS) on the foundation wall, then finish the rest as they require. The polyvinyl vapour barrier is pointless, but it won't damage anything, according to Building Science Corp. I've had to do the same nonsense on two new homes. The most economical thing to do along the stairs is to use 1/2" or 1" XPS, followed by drywall above the staircase. It shouldn't hang over the stringer. Underneath, you can go thicker, as it doesn't interfere with anything. Here is a link that might be useful: Basements

You might want to be careful with Spider. instead of just insulation, you're also introducing adheasive chemicals and moisture into your walls when you spray in Spider. Also, I hear that it is harder to rewire through spider if you ever need to do additional work down the road. Besides maximizing your energy savings with the greatest insulating power, don't take vapor barriers too lightly... Visqueen can trap moisture in your walls and cause BIG mold/mildew problems. If you're looking to do it right, you should look into smart vapor barriers.

Wianno, I don't think I was recommending wind barrier over vapor barrier under your joists. If I did, it was in error. Moisture/vapor retarder sheets on the ground under the house. Wind barrier stapled (or something) to the bottom of the floor joists. Insulation between the floor joists. (As much as will fit.) I wouldn't spray anything on the walls, except to try and patch a discrete hole (like where the electric line was punched, through) on the rubble walls. As Sharon said, anything sprayed (expanding foam, etc) has the possibility of damaging the stacking of the stones, causing settling and cracking. In some cases a careful re-pointing job might help, assuming your rubble wasn't dry laid in the first place. A dry laid rubble is helping to preserve your house from moisture and vapor being trapped under the house. Be very cautious about interrupting this cycle. Don't worry about the wind whistling through the rubble under your floors. If you have carefully insulated and sealed between the floor joists and at the sills, that's the best you can do. If you have pipes in this unheated space, re-route them before you block radiated heat from the structure with insulation. If you can't insulate the floor before winter, then, at least, insulate the pipes this year. But don't rely on pipe insulation in an otherwise unheated and insulated-from-the-living space area to keep the pipes from freezing. If you want to google for moisture/vapor barrier products, you'll probably find what I was suggesting. If I have a moment I'll go down and see if I can a get a tradename for you. Where are you? Molly~

If there is a vented attic, there should be no vapor barrier at the ceiling. A vapor barrier in a wall prevents moisture from entering the wall and condensing on the sheathing in the winter. In the ceiling, the moisture is taken away by the attic ventilation. The ceiling should, however, act as an air barrier so seal it well.