To begin, this is what the 3D energy model looks like when I open the Revit —
And this is what the model looked like when I exported it to Insight:
This analysis was done on the model exactly as given, without making any changes in Insight. I’m not sure why, but my initial analysis did not yield a 81 kBtu/ft2-yr EUI, but more like 74.
12/5 and R38:
I do recall Revit telling me that this file needed to be updated from 2019 to 2023 and that some things may have changed along the way, and so I’m wondering if the program maybe deleted some of the elements of the initial model we were given.
With the following settings, the EUI already reduced to around 51.4 kBtu/ft2-yr.
Building envelope factors:
For wall construction, I recommend R-38 wood framing for the walls. This seems like a reasonable choice of material and also reduces the EUI by almost 2 kBtu/ft2-yr. For the WWRs, the northern wall didn’t seem to matter at all, so I left it as is. For optimal EUI, the southern wall wouldn’t have any windows at all, but I thought this was unpleasant so I changed the WWR to 30%. The eastern and western walls had lower ratios (~15%). Adjusting the WWR on the western wall was particularly impactful.
For the window glass, these were the settings I chose. Honestly, ideally we would have triple paned low-emissivity glazing for the south and west directions (the ones that matter the most for energy use intensity), but since these might get quite costly, double paned would work as well if the issue of cost ever arose.
The shading was not particularly impactful on the EUI, but these were the settings I chose. East and north shades did not have any effect on EUI, so I left them as is.
To summarize, these were the building envelope settings I used:
- R-38 wood framed walls
- 30% WWR South, 15% WWR West, <30% WWR for East and anything goes for North
- Triple paned low-e glazing on all windows if possible
- 2/3 height shades on South and West (East and North don’t matter)
This was the resulting lowered EUI:
Power and lighting factors:
These were the settings I used. While I drove plug load efficiency to its highest possible efficiency, I left some range on the lighting efficiency, since I have the conception that if electric lighting is too low, this might create an unpleasant experience for the occupants (i.e. I hate being in Y2E2 at night because the lights are always so dim). For daylighting and occupancy controls, it appears that having occupancy controls is somewhat impactful on the model EUI, but daylighting controls don’t matter that much.
This is the resulting EUI after these changes:
If we max out our PV surface coverage at 90%, set it to maximum possible efficiency, and increase the payback time to over 20 years (either 20 or 30 years is fine), then we can achieve a pretty low building EUI!