780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 780 CMR: MASSACHUSETTS AMENDMENTS TO THE INTERNATIONAL BUILDING 
CODE 2009  
CHAPTER 13: ENERGY EFFICIENCY 
 
1300.1 Add the following sections as follows: 
 
1300.1 Adoption . Buildings shall be designed and constructed in accordance with the 
2015 International Energy Conservation Code  (IECC), as amended by 780 CMR 13.00.  
 
Concurrency.  Applications for building perm its and related construction and 
other documents filed through January 1, 2017, may comply either with 780 CMR 
13.00, 51.00: Massachusetts Residential Code , and 115.00: Appendix AA 
effective August 12, 2016, or with the vers ions of those provisions in effect 
immediately prior to August 12, 2016, but  not a mix of both. After January 1, 
2017, concurrency with the prior versions ends, and all applications for building 
permits and related construction and ot her documents shall comply with the 
amended provisions only. 
 
1301.1.1  Revise subsection as follows: 
 
[E] 1301.1.1 Criteria . Buildings shall be designed and constructed in accordance with 
the 2015 International Energy Conservati on Code (IECC) with Massachusetts 
Amendments in 780 CMR 13.00. These amendments apply to the IECC and to ANSI/ASHRAE/IESNA 90.1-2013.  
Exception.  Temporary structures, as regulated  by Section 3103, do not need to 
comply with the building envelope requirements of Chapter 13. 
 C401.2  Revise section as follows: 
 
C401.2 Application . Commercial buildings shall comply  with one of the following:  
 1. The requirements of AN SI/ASHRAE/IESNA 90.1-2013, as modified by C401.2.2 if 
following APPENDIX G and otherwise by C406.1. 
2. The requirements of Secti ons C402 through C405. In addi tion, commercial buildings 
shall comply with Section C406 and tena nt spaces shall comply with Section 
C406.1.1. 
3. The requirements of Sections  C402.5, C403.2, C404, C405.2, C405.3, C405.4, 
C405.6, and C407. The building energy cost, or the total annual energy use on either 
a site or source energy basis, shall be e qual to or less than 85% of the standard 
reference design building. S ource energy calculations shall comply with C401.2.2.1. 
4. Residential use buildings up to five stor ies may elect to comply with the energy 
provisions of Section N1106 found in 780 CMR 51.00: Massachusetts Residential 
Code , provided all units are sepa rately rated, separately me tered, individually heated 
and cooled, and have kitchens. 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
  
C401.2.2 through C401.2.2.2 Add subsection as follows: 
 
C401.2.2 Performance rating Method for Source Energy . Add exception to  
ANSI/ASHRAE/IESNA 90.1-2013 APPE NDIX G PERFORMANCE RATING 
METHOD, Section G1.1.  
 
Exception: When APPENDIX G is used for the comparison of building energy 
consumption only, the comparison may be performed on site energy and/or on a 
source energy basis.  
 
C401.2.2.1 Source Energy Method . For the purpose of quantifying the projected Source 
Energy consumption of a building the Site to  Source Fuel Conversion factors in Table 
401.2.2 shall apply. 
 
Table 401.2.2 Site to Source Fuel Conversion Factors 
Load Type Factor 
Electric power use at the utility meter 3.01 
Natural Gas 1.09 
Fuel Oil 1.13 
LPG 1.12 
Purchased District Heating 
Hot Water Steam  
1.35 1.45 
Purchased District Cooling 0.99 
Fossil fuels not listed 1.1 
Purchased Combined Heat and Power District Heat * 
*A source fuel conversion for purchased district  heat supplied by a comb ined heat and power 
central utility will be published by the Massachusetts Department of Energy Resources on a per district system basis.       
C401.2.2.2 Approved Software for Source Energy Calculation with 
Combined Heat and Power . 
 
1. Determination of the source energy c onsumption and usage intensity when 
using purchased combined heat and power  district heat shall be performed 
as an exceptional calculation using the Department of Energy Resources 
(DOER) approved Excel worksheet.  
2. Determination of the source energy c onsumption and usage intensity for 
heat generated by a combined heat a nd power system located on-site shall 
be performed using software meeti ng the requirements of ASHRAE 90.1-
2013 Normative Appendix G  Performa nce  Rating Method, Section G 2.2 
Simulation Program, and  has an explicitly stated capability to determine 
both the site and source energy use inte nsity for combined heat and power 
systems without the requirement for ex ceptional calculations as defined in 
ASHRAE 90.1-2013 Appendi x G Section G2.5.  780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
  
C402.2.5 Delete the Exception  
 
C402.3 through C402.3.1  Reserved.  
 
C402.6 Add section as follows: 
 
C402.6 Approved Calculation Software Tools .  The following software tools are 
sufficient to demonstrate compliance with Section C401.2:  
1. COMcheck: Version 4.0.4, or later. Can be accessed at: 
https://www.energycodes.gov/  
2. Any other software tool approved by the Board of Building Regulations and 
Standards. 
 
C405.1  Revise section as follows: 
 
C405.1 General (Mandatory) . This section covers lighting systems controls, the 
maximum lighting power for interior and exte rior applications, a nd electrical energy 
consumption.  
  
Exception: Dwelling units within commercial buildings shall not be required to 
comply with Sections C405.2 through C 405.5, provided that they comply with 
Section R404.1. Walk-in coolers, walk-in freezers, refrigerated warehouse coolers, and refrigerated warehouse freezers shal l comply with Section C403.2.15 or 
C403.2.16. 
 
C405.10  Reserved. 
 
C406.1  Revise section as follows: 
 
C406.1 Requirements . Buildings shall comply with at  least two of the following: 
 
1. More efficient HVAC performance in accordance with Section C406.2. 
2. Reduced lighting power density system  in accordance with Section C406.3. 
3. Enhanced lighting controls in accordance with Section C406.4. 
4. On-site supply of renewable energy in accordance with Section C406.5. 
5. Provision of a dedicated outdoor air sy stem for certain HVAC equipment in 
accordance with Section C406.6. 
6. High-efficiency service water heatin g in accordance with Section C406.7. 
 
Exception 1 : Buildings in municipalities not se rved by a participating Mass Save 
investor-owned gas or electric utility provi der shall comply with at least one of 
the requirements in Section C406.1. 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 Exception 2 : Buildings being designed ut ilizing ANSI/ASHRAE/IESNA 90.1-
2013 must comply with Item 2 of C406.1 as well as at least one of the remaining 
items listed in C406.1. 
 
C406.5 Revise section as follows: 
 
C406.5 On-site Renewable Energy . Total minimum ratings of on-site renewable energy 
systems shall comply with one of the following:  
1. Provide not less than 0.50 watts  per square foot (5.4 W/m
2) of conditioned 
floor area. 
2. Provide not less than 3% of the design  energy used within the building for 
building mechanical and service water heating equipment and lighting regulated in Chapter 4. 
3. Provide not less than 65% of the total annual energy used within the building 
for building space and service water hea ting with biomass fuel using direct 
vented combustion mechanical equipm ent rated at a minimum of 80 AFUE. 
The biomass fuel shall meet the elig ible fuel and emission criteria under 
M.G.L. c. 25A, § 11F½ (Massachusetts al ternative energy portfolio standard). 
4. Provide not less than 65% of the total annual energy used within the building 
for building space and service water h eating using a geothermal heat pump 
system with a coefficient of performance of not less than four. 
 
C407.6.1.1 through C407.6.1.5  Add subsections as follows: 
 
C407.6.1.1 Approved Alternative Energy Performance Methods . The requirements of 
this section are approved performance methods  to demonstrate compliance with Section 
C407 without calculation of a standard reference design: 
 
1. RESNET Approved Software for Home  Energy Rating System (HERS) .  
For residential units within a building up to five stories abov e grade plane, and 
with independent unit-level heating and cooling systems, a HERS rater 
verified Index Score of 55 or less for the finished units together with a 
completed and HERS rater verified ENERGY STAR Rater Field Checklist 
may be used.  Compliance with this s ection requires that the criteria of 
C402.4, C403.2, C404, and C405 are met. 
2. Passive House Institute US (PHIUS) Approved Software . PHIUS+ 2015: 
Passive Building Standard - North Ameri ca, or another approved software by 
PHIUS, where Specific Space Heat Demand, as modeled by a Certified 
Passive House Consultant, is le ss than or equal to 10 kBTU/ft
2/year.  
Compliance with this section require s that the criteria of C402.4, C403.2, 
C404, and C405 are met. 
3. ENERGY STAR Homes 3.1 path .  New residential structures, or additions 
to existing residential structures, or por tions thereof, as certified to conform 
with the ENERGY STAR Certifie d Homes standard, Version 3.1.  780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 4. Any other software and/or rating standa rd approved by the Board of Building 
Regulations and Standards. 
 C407.6.1.2 Documentation . The following documentation is required for energy code 
compliance under subsection C407.6.1.1, Item 1: s 
1. If using HERS Index software: 
a. Prior to the issuance of a building permit, the following items must be 
provided to the Building Official: 
i. a HERS compliance report which includes a proposed HERS 
Index  Score  of 55 or lower; 
ii. a description of the unit’s energy features; and 
iii. a statement that the rating index is “based on plans.”  
b. Prior to the issuance of a certificat e of occupancy, the following items 
must be provided to the building official: 
i. a copy of the final certificate indicating that the HERS Index 
Score for each unit is verified to be 55 or less, with a completed HERS rater verified ENERGY STAR Rater Field Checklist is to be submitted to the building official.  The HERS rating compliance shall be determined before electrical renewable energy systems are credited; and 
ii. a certificate, as required by S ection R401.3 for each unit, that 
lists the HERS Index Score of the dwelling unit. 
2. If using the PHIUS software: 
a. Prior to the issuance of a building permit , the following items must be 
provided to the Building Official: 
i. A list of compliance features; and 
ii. A statement that the estimated Specific Space Heat Demand is 
“based on plans.” 
b. Prior to the issuance of a certificat e of occupancy, the following item 
must be provided to the building official: 
i. A copy of the final report, subm itted on a form that is approved 
to document compliance with PHIUS+ 2015 standards.  Said report must indicate that the finished building achieves a 
Certified Passive House Consu ltant-verified Specific Space 
Heat Demand of less than  or equal to 10 kBTU/ft
2/year. 
3. If using ENERGY STAR Homes, Version 3.1 path: 
a. Prior to the issuance of a building permit, the following items must be 
provided to the Building Official: 
i. A copy of the preliminary HERS rating, based on plans; 
ii. A copy of the ENERGY STAR  v. 3.1 Home Report; and 
iii. A copy of the Rater Design Review Checklist. 
b. Prior to the issuance of a certificat e of occupancy, the following items 
must be provided to the Building Official: 
i. A copy of the certified HERS rating; and 
ii. A copy of the signed ENERGY ST AR Rater Field Checklist. 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
  
C407.6.1.3 Energy Rating Index . The Energy Rating Index (ERI) shall be a numerical 
integer value that is based on a linear scale c onstructed such that the ERI reference design 
has an Index value of 100 and a residential bui lding that uses no ne t purchased energy has 
an Index value of zero.  Each integer value on the scale shall represent a 1% change in 
the total energy use of the rated design relative to the total energy use of the ERI reference design.  The ERI shall consider all energy used in the residential building.  The 
RESNET Home Energy Rating System (HERS) Index is the approved ERI approach in 
Massachusetts. 
 
C407.6.1.4 ERI-based Compliance . Compliance based on an ERI analysis requires that 
the rated design be shown to have an ERI le ss than, or equal to, the appropriate value 
listed in Table C407.6.1.4, when compared to th e ERI reference design prior to issuance 
of any credit for onsite renewable electric generation. 
 
C407.6.1.4.1 Trade-off for Onsite Renewable Energy Systems .  New 
construction following C407.6.1.3, and existi ng buildings and additions following 
C501.4 may use any combination of the following renewable trade-offs to 
increase the maximum allowable HERS Index Score for each unit separately 
served by any combination of the following:  
1. Solar photovoltaic array, ra ted at 2.5kW or higher, shall offset five HERS 
points; 
2. Clean Biomass Heating System, solar thermal array, or ground source heat 
pump, or a combination of these syst ems, operating as the primary heating 
system shall offset five HERS points; and 
3. Solar thermal array for primary dom estic hot water heating or Clean 
Biomass Stove shall offset two HERS points.  
 
Note : a Clean Biomass Stove offset may not be combined with a primary heating 
system offset. 
 
Table C407.6.1.4 Maximum HERS Index Scores with Onsite Renewable Energy Systems  
Renewable Energy Source Maximum HERS Index Score 
New Construction Whole House Renovations; 
Additions 
None 55 65 
Solar PV > 2.5 kW, or 
Renewable primary heating system 60 70 
Solar PV & solar thermal DHW, or  
Renewable primary heating & solar 62 72 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 thermal DHW 
Solar PV & Renewable primary 
heating & solar thermal DHW 67 77 
 
C407.6.1.5 Verification by Approved Agency . Verification for compliance with Section 
C407.6.1 through C407.6.1.4.1 shall be completed by an approved  third party.  For 
compliance using a HERS Index rati ng or ENERGY STAR for Homes v. 3.1 
certification, verification of compliance shall be completed by a certified HERS rater.  
For compliance with PHIUS+ 2015, compliance sh all be completed by a certified Passive 
House consultant.