First, the initial model with occupancy of 12/5 and roof of R-38 gives:
Building envelope to reach Predicted Mean EUI of 54 kBtu/ft2/yr or lower:
I picked 14-inch ICF
0% for Eastern and Western walls, 4% on Northern walls, 15% on Southern walls
Triple Low-emissivity is the best (but probably expensive so it could be a good tradeoff to keep something like double glazing, and achieve more than 49.3 EUI but less than 54 target EUI)
2/3 of window height for Southern windows, and no shading devices on Northern windows
Overall, I achieved a reduction from 136 to 49.3 kBtu/sqft/yr:
Potential Impact of Power and Lighting Measures:
Overall, I reached EUI = 29.8 kBtu/ft²/yr (compared to 49.3kBtu/ft²/yr previously). Removing windows from the Eastern and Western facades had already decreased the EUI drastically, but plug load and lighting is a good way of decreasing energy consumption.
Benefits of Adding Photovoltaic Panels to Your Design
By covering 90% of the roof, allowing for a 20-year payback period, and using PV panels of 20.4% efficiency, I can further decrease the average EUI to reach a negative value of -12.1 kBtu/sqft/yr, with a range between -7.9 and -18.5 depending on the HVAC type and infiltration rate.
