Practice Exercise: Building Envelope SystemsPA

Your Name

Your building envelope recommendations for this practice exercise should feature:

  • Your recommended settings for the Insight Factor tiles
  • A screenshot from Insight showing the Predicted Mean EUI and the range of values resulting from your assumptions

  1. Original BIM Model

The EUI for the model as is about 74.4 kBtu/ft2/yr as shown below.



1c. Baseline Settings: Changing Operating schedule to 12/5 and roof construction to R38 causes the EUI to drop to 51.4 kBtu/ft2/yr as shown below

  1. These are the building envelope settings that I ended up choosing
    1. WWR: 0% WWR Southern walls, 30% WWR Nothern walls, <30% WWR Western walls and <15% WWR Western walls. For western walls, a WWR of 0% gave the lowest EUI but i just felt like, aside from the southern walls, the other walls needed some sort of openings for natural lighting
    2. Shading: 1/3 Win height for south and north, 2/3 Win height for west and east. Changing shading did not have much impact for the southern and nothern orientations
    3. Glazing: Trp Loe window glass gave the lowest EUI for all directions
    4. Infiltration: 0.17 ACH gave the lowest EUI

The overall resulting EUI is shown below as 36.5 kBtu/ft2/yr


  1. The following are the power and lighting measures taken to drive down the EUI even further
    1. Lighting efficiency: 0.3W/sf
    2. Both Daylighting and occupancy controls
    3. Plug load of 0.6W/sf
    4. This results in a lower EUI of 22.8 kBtu/sf/yr as shown below


  2. The following are solar PV settings taken to drive down the EUI further
    1. Surface coverage: 90%
    2. Panel efficiency of 20.4%
    3. Payback period of 20 years to allow the solar panels to pay back for themselves (30 years is also fine)

This results into the lowest EUI of -19.0 kBtu/sf/yr.


Even a 60% solar pv surface coverage still gives a negative EUI of -0.69kBtu/sf/yr which is a more realistic coverage in my opinion - this shows that a net zero design is possible when all these measures are taken (from the building envelope passive design to the operational energy and to sorucing of the energy usign solar pv)

The final EUI is -0.69kBtu/sf/yr as shown below (from 60% surface coverage)