residential energy efficiency

I just got my house audited for energy efficiency.
It is "surprisingly airtight for a home of its age (32years) in this neighborhood."
There were a few obvious air leaks (around attic hatches) and some surprising air leaks (like through the electical outlets and between the quarter-round and the floor below the patio door). Despite these easily addressed leaks, total air leakage is only the equivalent of a single 150sq.in. opening. Below 100sq.in is considered too airtight, and if you don't have a Heat-Recovery Ventilator, Health Canada recommends running bathroom fans and opening windows, even in winter.
I'll be getting an EnerGuide rating for the house and access to an online summary that I can project new ratings after various home improvements. Pretty neat stuff. People usually put their EnerGuide ratings in their furnace room but I think I'll be posting it on my lawn to spur a little competition with the neighbors. :)

No.1 on the energy-efficiency hit list: FURNACE
Currently have mid-efficiency (approx 80%), while high-efficiency furnaces are rated at 94%.
New furnaces are also direct-vented so they don't require a fresh air intake (obvious source of air-leakage).

Number 2 on the hit list: HOT WATER TANK.
Tanks with a pilot light have a constant flow of air to the chimney, actually drawing a lot of heat out of the water when the burner is not on! Better tanks have electronic ignition and exhaust blowers so air doesn't flow through the core unless the burner is on. This could also be direct-vented so the fresh-air intake could be eliminated altogether.

Cherry picking: weather-stripping the attic hatches and using childproof plugs to cap all the outlets on the outside walls.

Other interesting things I learned:

• 76% of all energy consumption in a house is due to heating, while appliances and lighting only account for 12% each (in the average home, according to StatsCan).
• Adding plastic wrap over windows only increases the R value from R2 to R3, iff installed properly, and can improve air-tightness (again, iff installed properly).
• Changing exterior doors only improves overall energy efficiency by ~1%.
• Refinishing hardwood floors also does a great job of sealing them and the baseboards.
• Gas hot water heaters are approx 65% efficient when operating, but only approx 50% efficient overall since cool air flows steadily through the core the rest of the time, drawing the heat out.
• Furnace efficiency is rated at steady-state, and there is a lot of energy lost when the burners first come on. For this reason, dual-stage furnaces are more efficient since they only use half the burners, at peak efficiency, for much longer periods of time, and only fire up the other two when it can't keep up.
• Traditional AC blower motors (forced air systems) consume approx 250W while their DC equivalent only consume 75W. This can make a significant difference especially if the blower operates continuously all day long.

I asked tons of questions throughout, and he wasn't afraid to tell me like it is (unlike house inspectors who fear any liability). I highly recommend doing this audit before starting any home improvements!