[rainbowzootsuit]

I would suggest that folks interested in energy efficiency improvement take a spin with NREL's BEopt software.

It allows you to make a simple 3D model of your home, enter its current state of construction (insulation, HVAC system, roof, solar panels, etc.), and then uses the DOE's energy plus (e+) software to run energy analysis for different scenarios of modification to the building.

For example you can find the optimal balance between improvement to your insulation vs getting a more efficient HVAC system in terms of dollars or energy usage, depending on your goals for your home.

https://www.nrel.gov/buildings/beopt.html

[bake]

Great suggestion -- HPH was a stab at making more sophisticated tools like that more approachable for homeowners, but for folks able and inclined to use the more powerful software out there (including energy plus and open studio), it could be really useful.

One thing we've built but not yet included in the site is a way to back into a more precise heating/cooling load for the home using past utility bills. That could be useful even for folks going down the more bottoms-up modeling route as a way to help with the 'garbage in / garbage out' problem of having to estimate insulation, window heat transfer, etc. etc.