Candice Delamarre

Property

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:

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Thermal Properties of Wall Surface (Wall Construction) for all orientations

I picked 14-inch ICF

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Glazing % (Window-to-Wall Ratio) for each orientation (North, South, East, West)

0% for Eastern and Western walls, 4% on Northern walls, 15% on Southern walls

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Thermal Properties of Glazing Surfaces for each orientation

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)

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Window Shading amount for each orientation

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:

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Plug Load Efficiency (the equipment and appliances that draw power): 0.6W/sf

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Lighting Efficiency (based on the efficiency of the lighting fixtures): 0.3W/sf

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Daylighting & Occupancy Controls: occupancy controls only (adding daylighting controls on top doesn't decrease EUI)

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.