scope:

FOREWORD

Addendum c to Standard 100-2018 makes the following changes to the standard:

• Moves Standard 100 from a basis of CBECS 2003/RECS 2005 to an updated basis on CBECS 2012/RECS 2015. As a result, EUI target values and many values in supporting tables throughout the standard have changed.

• Two new commercial building types were added to the CBECS survey in 2012 (Courthouse/Probation Office and Bar/Pub/Lounge). As a result, metrics for these two additional building types are included in the tables for the 2022 update.

• Targets for the building type of "hospital/inpatient health" were changed to be based on the subset of CBECS "hospital/inpatient health" buildings (CBECS variable PBAPLUS=35) located at a "hospital or other health care complex "(CBECS variable FacAct=8). This was done to ensure that targets used for hospitals would be based on a more homogeneous group of buildings representing hospitals (about 3/4 of the CBECS hospital/inpatient health observations were located on a hospital or other health care complex while the other 1/4 of these observations were mostly stand-alone buildings and believed to contain a large number of rehabilitation and psychiatric care buildings which could potentially affect the hospital/ inpatient health target.

• Analysis showed the hospitals subset represented a population of 5589 buildings (which is similar to the 5723 reported by statista.com for 2012), and the resulting targets were more in line with American Society for Health Care Engineering findings. Further analysis showed that using the resulting hospital/inpatient health targets for other (nonhospital) inpatient health care facilities would be reliable (for sourceenergy-use based targets) and perhaps a bit generous (a little easier to meet the target) for other inpatient health care facilities

• This addendum uses a primary energy conversion factor of 2.74 for electricity (see Table 5-2b) reflecting continued growth in the percentage of renewable energy on the U.S. electricity grid.

• This differs from the 3.15 value used in Standard 100-2018. This causes primary-energy-based (sourceenergy-based) EUIs within the standard to decrease. When combined with gains in building efficiencies that occurred between 2003 and 2012, these should cause most primary-energy-based EUIs in this addendum to be significantly less than those in the 2018 standard. Users of the standard should note EUI changes here are not the sole effect of building efficiency gains.

• Adds in three new climate zones (zones 0A, 0B, and 1B) that represent hot and humid climate zones nearer the equator. Metrics for these climate zones are included in many tables for the update.

• Changes a calculation in the analysis procedure for the RECS database was undertaken in the update.

• To calculate the residential EUIs in Standard 100-2018, the difference between RECS 2005 variables for total floor area (sqft8) and garage floor area (totgargsqft) was used as the denominator for calculating EUIs. This was an attempt to remove unconditioned or semi-conditioned space from the EUI computation (the standard requires a EUI calculation to be made based on conditioned space). RECS 2015 does not report the garage floor area. As a result, this addendum used the difference between the RECS 2015 total floor area variable (totsqft_en) and assumed garage floor areas for 1-car, 2-car, and 3+-car garages as an approximation for the denominator in the EUI calculation. This provided an approximation for conditioned space to improve the consistency between EUI calculations for the 2018 standard.

Note: In this addendum, changes to the current standard are indicated in the text by underlining (for additions) and strikethrough (for deletions) unless the instructions specifically mention some other means of indicating the changes.