The old attic insulation was removed on a Saturday. The following Friday two pallets of insulation were delivered to the house. The next day the wiring guys came to install new wiring (goodbye knob and tube - hello 2009 wiring!). That same night we laid the new insulation. Before all this was completed the furnace would run non-stop. When we woke up on Sunday morning not only was the furnace not running - but the house was actually warm!! Yay for energy efficiency!