780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 N1100.1 Add the following sections as follows: 
 
1100.1 Adoption . Buildings shall be designed and constructed in accordance with the 
2015  International Energy Conservation C ode (IECC), as amended by 780 CMR 51.00 
sections N1100.1 through N1111.2, as amended.  
 
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: Energy Efficiency , 51.00, and 115.00 Appendix AA effective August 12, 
2016, or with the versions of those provi sions in effect i mmediately prior to 
August 12, 2016, but not a mix of both. Af ter January 1, 2017, concurrency with 
the prior versions ends, and all applic ations for building permits and related 
construction and other documents shall comply with the amended provisions only. 
 
N1101.1  Revise the section as follows: 
 
N1101.1 Scope . This chapter regulates the energy efficiency for the design and 
construction of buildings regulated by 780 CM R.  Municipalities wh ich have adopted the 
Stretch Energy Code shall use the energy efficiency requirements of 780 CMR 115.00: 
Appendix AA.  
 N1101.6 (R202)  Add and/or revise the following defined terms: 
 
CLEAN BIOMASS STOVE . Wood- or pellet-fired stoves that are EPA certified; and 
have a particulate matter emi ssions rating of no more than 3.5 g/hr for non-catalytic wood 
and pellet stoves; or 2.0 g/hr fo r catalytic wood and pellet stoves. 
 
CLEAN BIOMASS HEATING SYSTEMS . Wood-pellet fired central boilers and 
furnaces where the equipment has a thermal e fficiency rating of 80% (higher heating 
value) or greater; and a particulate ma tter emissions rating of no more than 0.15 
lb/MMBtu PM heat output. 
 
N1101.13  Revise the section as follows: 
 
N1101.13 (R401.2) Compliance . Projects shall comply w ith one of the following: 
 
1. Sections N1101.14 through N1104. 
2. Section N1105 and the provisions of Sections N1101.14 through N1104 
labeled “Mandatory.” 
3. An energy rating index (ERI) approac h, or approved alternative energy 
performance rating method in Section N 1106 and the provisions of Sections 
N1101.14 through N1104 labeled “Mandatory.” 
 Qualifying approaches under N1106 include the following: 
a. Certified RESNET HERS rating with Massachusetts amendments. 
b. Certified Energy Star  Homes, Version 3.1. 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 c. Certified Passivehaus performance method. 
 N1101.14 (R401.3) Add the following to the end of the paragraph: 
  “The Certificate shall list the final HERS Index Score when applicable.” 
 
Table N1102.1.2 (R402.1.2)  Revise the table as follows: 
  Climate Zone 5 and Marine 4 Fenestration U Factor shall be “0.30”.  Table N1102.1.4 (R402.1.4)  Revise the table as follows: 
  Climate Zone 5 and Marine 4 Fenestration U Factor shall be “0.30”.  N1102.1.5.1  Add the subsection as follows: 
 
N1102.1.5.1 Approved Software for Total UA Alternative : The following software is 
approved for demonstrating Total UA compliance: 
1. REScheck Version 4.6.2 or later, available at 
http://www.energycodes.gov/rescheck  
2. REScheck-Web available at https://energycode.pnl.gov/REScheckWeb/  
 
N1103.3.3 (R403.3.3)  Add the following paragraph before the exception: 
 
Post-construction or rough-in testing and ve rification shall be done by a HERS Rater, 
HERS Rating Field Inspector, or an a pplicable BPI Certified Professional. 
 
N1103.6 (R403.6)  Replace the section as follows: 
 
N1103.6 (R403.6) Mechanical Ventilation (Mandatory) . Each dwelling unit of a 
residential building shall be provided with  continuously operating exhaust, supply or 
balanced mechanical ventilation that has been  site verified to m eet a minimum airflow 
per: 
1. the Energy Star Homes’ Version 3.1; 
2. ASHRAE 62.2-2013; or 
3. the following formula for one- and two- family dwellings and townhouses of 
three or fewer stories above grade plane: 
 
Q = .03 x CFA + 7.5 x (N br +1) - 0.052 x Q 50 x S x WSF 
 
Where:  CFA is the conditioned floor area in sq ft 
Nbr is the number of bedrooms 
Q50 is the verified blower door air leakage rate in cfm measured at 
50 Pascals S is the building height factor  determined by this table: 
 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 Stories Above 
Grade Plane 1 2 3 
S 1.00 1.32 1.55
 
WSF is the shielded weather factor  as determined by this table: 
 
County WSF 
Barnstable 0.60 
Berkshire 0.52 
Bristol 0.54 
Dukes 0.59 
Essex 0.58 
Franklin 0.52 
Hampden 0.49 
Hampshire 0.59 
Middlesex 0.55 
Nantucket 0.61 
Norfolk 0.52 
Plymouth 0.53 
Suffolk 0.66 
Worcester 0.59 
 
 N1103.6.2 (R403.6.2) through N1103.6.6 (R403.6.6)  Add the subsections as follows: 
 
N1103.6.2 (R403.6.2) Verification .  Installed performance of the mechanical ventilation 
system shall be tested and verified by a HE RS Rater, HERS Rating Field Inspector, or an 
applicable BPI Certified Professional, and measured using a flow hood, flow grid, or 
other airflow measuring device in accordance with either RESNET Standard Chapter 8 or 
ACCA Standard 5. 
 
N1103.6.3 (R403.6.3)  Air-moving Equipment, Se lection and Installation . As 
referenced in ASHRAE Standard 62. 2-2013, Section 7.1, ventilation devices and 
equipment shall be tested and certifie d by AMCA (Air Movement and Control 
Association) or HVI (Home Ventilating Instit ute) and the certification label shall be 
found on the product. Installation of systems or equipment shall be carried out in 
accordance with manufacturers’ design requireme nts and installation instructions. Where 
multiple duct sizes and/or exterior hoods are standard options, the minimum size shall not 
be used. 
 
N1103.6.4 (R403.6.4)  Sound Rating .  Sound ratings for fans used for whole building 
ventilation shall be rated at a maximum of 1.0 sone. 
 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 Exception :   HVAC air handlers and remote-m ounted fans need not meet sound 
requirements.  There must be at least 4 feet of ductwork between the remote-
mounted fan and intake grille.  
 
N1103.6.5 (R403.6.5)  Documentation . The owner and the occupa nt of the dwelling unit 
shall be provided with information on the ventilation design and systems installed, as 
well as instructions on the proper operation a nd maintenance of the ventilation systems.  
Ventilation controls shall be labeled with re gard to their function, unless the function is 
obvious.  
 
N1103.6.6 (R403.6.6) Air Inlets and Exhausts . All ventilation air inle ts shall be located 
a minimum of ten feet from vent openings fo r plumbing drainage systems, appliance vent 
outlets, exhaust hood outlets, vehicle exhaust,  or other known contamination sources; and 
shall not be obstructed by snow, plantings, or any other material . Outdoor forced air 
inlets shall be covered with rodent screens having mesh openings not greater than ½ inch.  
A whole house mechanical ventilation system shall not extract air from an unconditioned 
basement unless approved by a registered design professional. Where wall inlet or 
exhaust vents are less than seven feet above finished grade in the area of the venting, 
including but not limited to decks and porches, a metal or plastic identification plate shall 
be permanently mounted to the exterior of th e building at a minimum height of eight feet 
above grade directly in line with the vent terminal. The si gn shall read, in print size no 
less than ½ inch in size, “MECH. VENT  DIRECTLY BELOW. KEEP CLEAR OF ALL 
OBSTRUCTIONS.” 
 
Exceptions :  
1. Ventilation air inlets in the wall ≥ three feet from dryer exhausts and 
contamination sources exiting through the roof. 
2. No minimum separation distance shall be  required between local exhaust outlets 
in kitchens/bathrooms and windows. 
3. Vent terminations that meet the requirements of the National Fuel Gas Code 
(NFPA 54/ANSI Z223.1)  or equivalent. 
 
N1104.3 (R404.2) Reserved.  
 
N1106.1 (R406.1) through N1106.1.2  Revise and/or add the secti on and subsections as follows: 
 
N1106.1 (R406.1) Scope . This section establishes criteria for compliance using an 
Energy Rating Index (ERI) analysis, or appr oved alternative ener gy performance rating 
methods. 
 
N1106.1.1 (R406.1.1) Approved Alternativ e Energy Performance Methods . 
The following rating threshold criteria ar e sufficient to demonstrate energy code 
compliance under section N1106 without cal culation of a standard reference 
design. The mandatory provisions  of subsection N1106.2 also apply: 
 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 1. ENERGY STAR Homes 3.1 path . New buildings shall be certified to 
conform to the ENERGY STAR Certified Homes, Version 3.1 standard.  
2. Passive House Institute US (PHIUS) Approved Software . PHIUS+ 
2015: Passive Building Standard - No rth America, or another approved 
software by PHIUS, where Specific Space Heat Demand, as modeled by a Certified Passive House Consulta nt, is less than or equal to 10 
kBTU/ft
2/year.  Compliance with this sect ion requires that the criteria 
of C402.4, C403.2, C404, and C405 are met.  
3. Any other software and/or rating st andard approved by the Board of 
Building Regulations and Standards.  
 
N1106.1.2 (R406.1.2) Documentation . The following documentation is required 
for energy code compliance under subsection N1106.1.1:  
1. 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 ST AR v. 3.1 Home Report; 
and 
iii. A copy of the Rater Design Review Checklist. 
b. Prior to the issuance of a certificate of occupancy, the 
following items must be provide d to the Building Official: 
i. A copy of the certified HERS rating; and 
ii. A copy of the signed ENERGY STAR Rater Field 
Checklist. 
 
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 certificate of occupancy, the 
following item must be provide d to the building official: 
i. A copy of the final report, submitted 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 Consultant-
verified Specific Space Heat Demand of less than or equal to 10 kBTU/ft
2/year. 
 N1106.3 (R406.3)  Add the following sentence to  the end of the paragraph: 
 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 “The RESNET Home Energy Rating System (HERS) Index is the approved ERI 
approach in Massachusetts.” 
 N1106.4 (R406.4) Revise the section as follows: 
 
N1106.4 (R406.4) ERI-based Compliance . Compliance based on an ERI analysis 
requires that the rated design  be shown to have an ERI less than or equal to the 
appropriate value listed in Table N1106.4 wh en compared to the ERI reference design 
prior to credit for onsite re newable electric generation. 
 
N1106.4.1 (R406.4.1) Add the subsection, and associated table, as follows: 
 
N1106.4.1 (R406.4.1) Trade-off for Onsite Renewable Energy Systems. New 
construction following N1106.3 or existing buildings and additions following N1107.4 
may use any combination of the following renewable energy 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. 
3. Solar thermal array for primary domestic  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 N1106.4.1 (R406.4.1) . Maximum HERS Index Scores with Onsite Renewable Energy 
Systems  
Renewable Energy Source Maximum HERS Index 
New Construction Whole House Renovations; 
Additions 
None 55 65 
Solar PV > 2.5kW, or Renewable primary heating system 60 70 
Solar PV & solar thermal DHW, or  
Renewable primary heating & solar thermal DHW 62 72 
Solar PV & Renewable primary heating 
& solar thermal DHW 67 77 
 
N1106.5 (R406.5)  Revise the section as follows: 
 780 CMR: STATE BOARD OF BUILDI NG REGULATIONS AND STANDARDS 
 
 N1106.5 (R406.5) Verification by Approved Agency. Verification of compliance with 
Section N1106 shall be completed by an approved  third party. For compliance using a 
HERS rating or Energy Star Homes 3.1 certifi cation, verification of compliance shall be 
completed by the certified HERS rater. Fo r compliance using PHIU S+ 2015, verification 
of compliance shall be completed by a certified Passive House consultant. 
 N1108.1.2 (R502.1.2)  Add an exception to the subsection as follows: 
 
Exception:   Alternatively, the additi on and any alterations that are part of the project 
shall comply with N1106 and shall achieve a maximum HERS Index Score using Table 
N1106.4.1. 
 
APPENDIX U: Reserved.