Hmmm. Interesting - the link I suggested doesn't go where it's supposed to.
OK - Do this - go to www.auralex.com, then click on acoustic university 101. Everything you need regarding setting up the room / construction including walls, floors, ceiling, windows, HVAC etc at no charge.
And - it's for starving musicians, not well heeled audiophiles - send a description of your room and they'll suggest treatment schemes and lots of cool pictures -again for free - try it, you'll like it.