CS88 Energy Code Feasibility Study in Amesbury, Massachusetts

Energy code feasibility study for a 83-unit Townhomes in Massachusetts. Compares multiple design paths. Recommended: NEXTGEN (All-Electric). View full study.

Study Type: Energy Code Feasibility Study
State: Massachusetts
Units: 83
Building Type: Townhomes
Fuel Type: All-Electric
Recommended Path: NEXTGEN (All-Electric)

Goal

To find the most cost-effective compliance path, this report isolates energy code related costs from total construction. We use real bid data from vendors & clients to create a reliable framework for aligning incentives and design, with all recommendations confirmed by detailed energy modeling.

Project

Amesbury, MA 01913
37 Buildings | 83 Units | 177,740 SF Conditioned
New Construction | 3-story 1-unit townhome (x11), 3-story 2-unit townhome (x10), 3-story 3-unit townhome (x12), 3-story 4-unit townhome (x4)
All-Electric OR Mixed Fuel | 2021 IECC with MA Amendments (Stretch Code) | HERS ≤ 45 (All-Electric) OR HERS ≤ 42 (Mixed Fuel) | ENERGY STAR SFNH v3.2 (optional) | ENERGY STAR NextGen (optional)

Overview

Read This: This report compares different ways you can build the project and meet energy code, looking at both cost and incentives, with the ultimate goal as finding the most affordable path.

The overview outlines the key differences between each of the paths we show in this report and why we recommend the one we picked over the others.
The recommended design section is where we share the requirements and incentives for the path we think is best based on affordability.
The path comparison section shows the detailed requirements and incentives for each path we compared, basically showing our work if you want to dig in.

Product Recs: All product recommendations are recommendations only and can be substituted with any equivalent or better match.

Path Summaries

All three paths meet Massachusetts energy code and are modeled to pass on a lean margin, so the choice between them is a matter of cost and constructability rather than compliance.

NEXTGEN (All-Electric): Recommended

This is the least expensive path at approximately $35.39/sf net, and the air barrier sits on the sheathing. It keeps the project fully electric, which preserves the $1,245,000 Mass Save ENERGY STAR single-family townhome incentive ($15,000 per home) and aligns with the direction Massachusetts energy code is heading. For this project, this is the right choice.

HERS40-ELECTRIC (All-Electric): Alternative

At approximately $39.54/sf net, about $4/sf more than the NEXTGEN path, this path stays all-electric and adds $20,750 in incentives, which does not close the cost gap. The two all-electric paths build in much the same way, so the premium buys a deeper margin under the code ceiling. Choose this path when that margin matters more than first cost.

HERS40-GAS (Mixed-Fuel): Not Recommended

This is the most expensive path at approximately $48.84/sf net, about $13/sf more than the NEXTGEN path, and it is the most labor-intensive to build. Mixed-fuel construction forfeits the $1,245,000 Mass Save ENERGY STAR single-family townhome incentive and runs against the direction Massachusetts energy code is heading. The only reason to choose this path is a market that specifically demands gas service.

What Changes Between Paths

Item	HERS40-GAS	HERS40-ELECTRIC	NEXTGEN (Recommended)
Exterior Walls	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-10 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-10 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-9 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).
Roof	Vented attic: ≥ R-60 insulation.	Vented attic: ≥ R-60 insulation.	Vented attic: ≥ R-49 insulation.
Windows & Glass Doors	High performance, U ≤ 0.18 / SHGC ≤ 0.18.	High performance, U ≤ 0.18 / SHGC ≤ 0.18.	High performance, U ≤ 0.25 / SHGC ≤ 0.25.
HVAC	Natural gas boiler (as modeled); AFUE ≥ 96; cooling by a separate system, cooling only; SEER2 ≥ 15.2. See HVAC Design Loads.	Ducted air-source heat pump (as modeled); SEER2 ≥ 17.5; HSPF2 ≥ 10.5. See HVAC Design Loads.	Ducted air-source heat pump (as modeled); SEER2 ≥ 17.5; HSPF2 ≥ 10.5; 5 kW electric heat kit on every four-bedroom unit. See HVAC Design Loads.
DHW	Gas tankless water heater (as modeled); UEF ≥ 0.96.	3-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 4; 65 gal 4-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 4; 80 gal	3-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 3.5; 65 gal 4-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 3.5; 80 gal
Clothes Dryer	Standard electric dryer; vented; CEF ≥ 3.93.	Heat pump dryer; ventless; CEF ≥ 8.5.	Standard electric dryer; vented; CEF ≥ 3.93.
Stove / Oven	Electric range.	Electric induction cooktop; convection oven.	Electric range.
Cost $/sf	$48.47	$46.19	$42.02
Incentive $/sf	$0.00	$7.12	$7.00
Net $/sf	$48.84	$39.54	$35.39

Single Family OR Low Rise Buildings (Stretch)

Code Path

HERS: Amesbury Stretch. Three-story dwellings under 225 CMR 22. The all-electric Stretch ceiling is HERS ≤ 45 and the mixed-fuel Stretch ceiling is HERS ≤ 42 (225 CMR 22 Table R406.5).

Permit Requirements

HERS: Proposed HERS/ERI compliance documentation for each dwelling unit type (rated Index, software name/version, modeling inputs) and component specifications on the drawings, with the building permit application (225 CMR 22 R406).

Certificate of Occupancy Requirements

HERS: Confirmed as-built HERS certificates; dwelling-unit air-leakage testing (and duct / ventilation verification where required) per the adopted testing rules and ANSI/RESNET/ICC 380 methods, with sampling as allowed for multifamily.

Recommended Design

This section outlines the design requirements, product recommendations, and incentives for the design that we believe will be the most affordable path to meeting energy code.

Recommended Design - Incentives

Incentives Available: $1,245,000

MassSave Single-Family ENERGY STAR NextGen Tier ($1,245,000) (Program Breakdown): You get this rebate for building a home that meets MassSave's ENERGY STAR NextGen tier. The 2026 program terms require all-electric space conditioning, water heating, cooking and clothes drying; a HERS Index of 45 or lower, or at least 30 percent savings over the Massachusetts User Defined Reference Home; air leakage of 1.5 ACH50 or lower, tested by an approved HERS rating company; balanced ventilation through an ERV or HRV; an EV-ready parking space built to 225 CMR 22 section R404.4; and certification by a program-approved HERS rating company to ENERGY STAR Single-Family New Homes v3.2 (or Multifamily New Construction v1.2) and to ENERGY STAR NextGen. Testing and certification typically happen at the end of construction, around when the certificate of occupancy is received. This rebate comes in the form of a check within 4 months of the certification paperwork being provided to MassSave.

HVAC Design Loads

Essex County, MA · heating 1.0°F/70.0°F · cooling 90.0°F/75.0°F · all values kBtuh · 5 kW backup heat kit on some unit types

Design heat loss · components

Unit type	Walls & rim joists	Roof / ceiling	Slab, floors & below grade	Windows & doors	Infiltration	Ventilation	Design heat loss	Design heat loss at selection
3-Bedroom	6.3	3.0	5.8	9.9	3.8	3.3	32.2 @ 1°F	32.2 @ 1°F
4-Bedroom	10.7	2.4	13.1	8.9	3.9	3.9	43.1 @ 1°F	43.1 @ 1°F

Design heat gain · components

Unit type	Solar through glazing	Envelope conduction	Internal gains	Infiltration & ventilation	Latent	Total heat gain	Sensible heat ratio
3-Bedroom	4.7	4.4	2.5	2.6	4.1	18.4	0.78
4-Bedroom	4.9	5.8	2.8	3.0	4.7	21.2	0.78

Selection

Unit type	Cooling Capacity	Minimum Heating Capacity
3-Bedroom	16.6 to 23.9 kBtuh rated	≥ 32.2 kBtuh @ 1°F
4-Bedroom	19.1 to 27.6 kBtuh rated	≥ 43.1 kBtuh @ 1°F

Heating coverage at 1°F

Unit type	Recommended unit	Heat pump output at 1°F	5 kW heat kit at 208 V (3.76 kW delivered)	Total heat at 1°F	Coverage
3-Bedroom	42 kBtuh nominal	37.0 kBtuh	Not on every unit	37.0 kBtuh	Pass by 4.8 kBtuh
4-Bedroom	48 kBtuh nominal	42.2 kBtuh	12.8 kBtuh	55.0 kBtuh	Pass by 11.9 kBtuh

ENERGY STAR Total UA

Item	Detail
Climate zone	IECC 5A (2021 IECC map, Footnote 6)
Program	ENERGY STAR Single-Family New Homes National v3.2 (Rev. 14)
Rule	Design Review Item 2.1: proposed total UA ≤ 100% of the UA from 2021 IECC Table R402.1.2 U-factors on the same areas (Footnote 7)
Code reference	National Rater Design Review Checklist Rev. 14, Item 2.1 with Footnotes 6 to 8; 2021 IECC Table R402.1.2 and Section R402.1.5
Areas and U-factors	Energy model, per home: walls net of windows and doors, rim joists as above-grade wall
Openings	Opaque doors use the fenestration U-factor. Footnote 8a/8b exemptions not needed: every window and door meets U-0.30
Fenestration	Area-weighted window and door U 0.25, limit 0.48 (R402.5); no SHGC limit in CZ 5A (Table R402.1.2 NR; Item 2.2 covers CZ 1-3, 4A and 4B only)

Assembly	Proposed spec
Walls	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-9 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).
Rim joists	≥ R-21 rim/band insulation at floor transitions.
Roof	Vented attic: ≥ R-49 insulation.
Slab	≥ R-20 perimeter insulation, 2 ft deep, at the interior face of the slab edge, plus ≥ R-20 under-slab insulation, 2 ft wide; provides a full thermal break.
Windows	High performance, U ≤ 0.25 / SHGC ≤ 0.25.
Doors	Opaque door, U ≤ 0.20 (R-5.0).

Component UA

Component	Area	Proposed U or F	Proposed UA	Reference U or F	Reference UA
Above-grade walls (net of openings)	10,702 sf	0.0394	421.8	0.045	481.6
Rim joists	1,163 sf	0.0476	55.4	0.045	52.3
Ceilings	6,850 sf	0.0243	166.5	0.024	164.4
Floors over unconditioned	500 sf	0.0357	17.9	0.033	16.5
Slab-on-grade edge (F x perimeter)	555 lf	0.5100	283.0	0.480	266.3
Windows	2,428 sf	0.2500	607.0	0.300	728.4
Opaque doors	120 sf	0.2000	24.0	0.300	36.0
Total			1,575.5		1,745.5

Total UA

Home	Proposed UA	Reference UA	% of reference	Result
3 BR, 2,100 sf	255.2	282.6	90.3%	PASS
4 BR, 2,000 sf	224.5	250.7	89.5%	PASS
3 BR, 2,160 sf	255.9	283.3	90.3%	PASS
3 BR, 2,440 sf	313.0	346.8	90.3%	PASS
4 BR, 2,500 sf	386.6	425.5	90.9%	PASS
3 BR, 1,800 sf	140.2	156.6	89.5%	PASS
Result	1,575.5	1,745.5	90.3%	PASS

Recommended Design - Units

Item	Detailed Specifications
Exterior Walls	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-9 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.). (Product Rec).
Below Grade Walls	N/A
Corridor Walls	N/A
Slab	≥ R-20 perimeter insulation, 2 ft deep, at the interior face of the slab edge, plus ≥ R-20 under-slab insulation, 2 ft wide; provides a full thermal break.
Floor Over Unconditioned Space	N/A
Floor Over Garage	≥ R-30 cavity insulation.
Floor Over Podium	N/A
Rim Joists	≥ R-21 rim/band insulation at floor transitions.
Roof	Vented attic: ≥ R-49 insulation.
Windows & Glass Doors	High performance, U ≤ 0.25 / SHGC ≤ 0.25. (Product Rec).
Doors	Opaque door, U ≤ 0.20 (R-5.0).
Air Sealing	≤ 1.5 ACH50; tested. (Air Sealing Protocol)
HVAC	Ducted air-source heat pump (as modeled); SEER2 ≥ 17.5; HSPF2 ≥ 10.5; 5 kW electric heat kit on every four-bedroom unit. See HVAC Design Loads. (Product Rec).
Ductwork	Supply and return ducts in attic under insulation poorly vented insulated to code minimum; ducts in conditioned space insulated to code minimum.
Duct Sealing	≤ greater of 40 CFM25 or 4 CFM25 per 100 sqft of conditioned floor area; tested at rough-in, after the HVAC is installed. (Duct Sealing Protocol)
HVAC Grading	Fan Flow Test: Grade I Watt Draw Test: Grade I Refrigerant Charge: Grade I HVAC installer must provide photo of the digital refrigerant scale showing the amount charged, with the tank on the scale and hoses connected to the outdoor unit, along with a photo of the outdoor unit's data plate.
Mechanical Ventilation	In-unit ERV (Product Rec). 3-bedroom: 110 CFM, ≥ 81% ASRE 4-bedroom: 130 CFM, ≥ 79% ASRE
Local Mechanical Exhaust	Bathroom(s): at least 50 CFM intermittent and up to 3.0 sones, or at least 20 CFM continuous and up to 2.0 sones. Kitchen(s): at least 100 CFM intermittent and up to 3.0 sones, or continuous at 5 ACH. Both: exhaust directly outdoors with ENERGY STAR certified fans. A balanced ERV or HRV serving the space may satisfy this requirement.
Thermostats	Programmable thermostat (as modeled).
DHW	3-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 3.5; 65 gal (Product Rec). 4-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 3.5; 80 gal
DHW Piping	Supply piping insulated to ≥ R-3.
Water Fixtures	WaterSense certified (Lavatory ≤ 1.2 GPM; Shower ≤ 2.0 GPM; Kitchen ≤ 2.2 GPM).
Refrigerator	≤ 600 kWh/yr; electric. (Product Rec).
Dishwasher	≤ 240 kWh/yr; electric. (Product Rec).
Clothes Washer	IMEF ≥ 2.06; IWF ≤ 4.2; ≤ 152 kWh/yr; electric. (Product Rec).
Clothes Dryer	Standard electric dryer; vented; CEF ≥ 3.93. (Product Rec).
Stove / Oven	Electric range. (Product Rec).
Lighting	≥ 100% high-efficacy (LED).
Solar Ready	Reserve an unobstructed rooftop solar-ready zone (at least 300 sq ft; 150 sq ft for small townhouses) with structural capacity, a conduit pathway, and reserved electrical-panel space. Waived if solar is already installed or the roof is heavily shaded.
EV Ready	One 50-amp Level II EV-ready circuit per dwelling unit.
HPWH Ready	N/A
Paperwork & Modeling	ENERGY STAR energy model to the ERI target, the ENERGY STAR design-review checklist, and an HVAC design report. Plus ENERGY STAR NextGen documentation: all-electric equipment and EV-charging provisions.
Testing & Verification	ENERGY STAR field verification: pre-drywall and final inspections, blower-door and duct-leakage tests, ventilation airflow, and HVAC installation grading. Plus ENERGY STAR NextGen verification: all-electric equipment and EV-charging infrastructure.

Recommended Design - Common Areas

Item	Common Areas (Residential Building)

Assembly Moisture Check

This section shows which air and vapor barriers are needed, and why.

Inputs

Item	Value
Climate zone	5A
Indoor air	70 F, 35% RH
Dewpoint of that indoor air	41 F
Outdoor air	1 F
Code	2018 IRC Table R702.7.1

Exterior Walls

#	Layer (inside to outside)	R	Running R	Temp	Dewpoint target	Vs dewpoint
1	Drywall	1.13	1.13	67.6 F	41 F	OK
2	Class II vapor retarder	0.00	1.13	67.6 F	41 F	OK
3	R-21 cavity insulation with 2x6 wood studs	21.00	22.13	22.2 F	41 F	First below dewpoint
4	Wood sheathing	0.62	22.75	20.8 F	41 F	Below dewpoint
5	Air barrier	0.00	22.75	20.8 F	41 F	Below dewpoint
6	R-9 continuous insulation	9.00	31.75	1.4 F	41 F	Below dewpoint
7	Siding / cladding	0.17	31.92	1.0 F	41 F	Below dewpoint

Conclusion: Layer 3 is the first row below dewpoint. It is the cold plane we protect. Indoor moisture can turn to water if it gets there, and can eventually cause mold. It can get there two ways. It gets there through the drywall, which is why the vapor retarder is on the inside of the wall. It also gets there through holes (outlets, gaps, plates), which is why the air barrier is on the sheathing. Same at the rim. Keep the R-9 going over the band.

Slab

#	Layer (inside to outside)	R	Running R	Temp	Dewpoint target	Vs dewpoint
1	Concrete slab	0.50	0.50	69.5 F	41 F	OK
2	Vapor retarder	0.00	0.50	69.5 F	41 F	OK
3	R-20 under slab and at the interior edge	20.00	20.50	50.0 F	41 F	OK
4	Gravel / ground	0.00	20.50	50.0 F	41 F	OK

Conclusion: No row drops below dewpoint. This is not the wall problem. Indoor air is not leaking to a cold sheathing. The vapor retarder is under the slab to stop moisture coming up from the ground. The slab itself is the air barrier.

Floor Over Garage

#	Layer (inside to outside)	R	Running R	Temp	Dewpoint target	Vs dewpoint
1	Floor finish	1.13	1.13	67.5 F	41 F	OK
2	R-30 cavity insulation	30.00	31.13	1.4 F	41 F	First below dewpoint
3	Air barrier	0.00	31.13	1.4 F	41 F	Below dewpoint
4	Garage	0.17	31.30	1.0 F	41 F	Below dewpoint

Conclusion: Layer 2 is the first row below dewpoint. It is the cold plane we protect. Indoor moisture can turn to water if it gets there, and can eventually cause mold. It can get there through holes, which is why the air barrier is at the insulated plane, not a drop-in ceiling.

Roof (vented attic)

#	Layer (inside to outside)	R	Running R	Temp	Dewpoint target	Vs dewpoint
1	Drywall ceiling	1.13	1.13	68.4 F	41 F	OK
2	Air barrier	0.00	1.13	68.4 F	41 F	OK
3	R-49 attic floor insulation	49.00	50.13	1.2 F	41 F	First below dewpoint
4	Vented attic	0.17	50.30	1.0 F	41 F	Below dewpoint

Exterior Walls (Recommended Design)

Slab (Recommended Design)

Floor Over Garage (Recommended Design)

Rim Joists (Recommended Design)

Roof (Recommended Design)

Path Comparison

This section shows the detailed requirements and incentives for each path we compared, basically showing our work of how we determined the recommended path is the most affordable way of meeting energy code compliance.

Path Comparison - Incentives

NEXTGEN: $1,245,000

MassSave Single-Family ENERGY STAR NextGen Tier ($1,245,000) (Program Breakdown): You get this rebate for building a home that meets MassSave's ENERGY STAR NextGen tier. The 2026 program terms require all-electric space conditioning, water heating, cooking and clothes drying; a HERS Index of 45 or lower, or at least 30 percent savings over the Massachusetts User Defined Reference Home; air leakage of 1.5 ACH50 or lower, tested by an approved HERS rating company; balanced ventilation through an ERV or HRV; an EV-ready parking space built to 225 CMR 22 section R404.4; and certification by a program-approved HERS rating company to ENERGY STAR Single-Family New Homes v3.2 (or Multifamily New Construction v1.2) and to ENERGY STAR NextGen. Testing and certification typically happen at the end of construction, around when the certificate of occupancy is received. This rebate comes in the form of a check within 4 months of the certification paperwork being provided to MassSave.

HERS40-ELECTRIC: $1,265,750

MassSave Single-Family ENERGY STAR NextGen Tier ($1,245,000) (Program Breakdown): You get this rebate for building a home that meets MassSave's ENERGY STAR NextGen tier. The 2026 program terms require all-electric space conditioning, water heating, cooking and clothes drying; a HERS Index of 45 or lower, or at least 30 percent savings over the Massachusetts User Defined Reference Home; air leakage of 1.5 ACH50 or lower, tested by an approved HERS rating company; balanced ventilation through an ERV or HRV; an EV-ready parking space built to 225 CMR 22 section R404.4; and certification by a program-approved HERS rating company to ENERGY STAR Single-Family New Homes v3.2 (or Multifamily New Construction v1.2) and to ENERGY STAR NextGen. Testing and certification typically happen at the end of construction, around when the certificate of occupancy is received. This rebate comes in the form of a check within 4 months of the certification paperwork being provided to MassSave.
Induction Cooktop Adder ($20,750) : A MassSave market transformation adder of $250 per unit for installing an induction cooktop in each dwelling unit. This rebate comes in the form of a check within 4 months of certification documentation being provided to MassSave, typically this is 4 months after construction is complete.

HERS40-GAS: $0

No MassSave Incentive On The Mixed-Fuel Path ($0) (Program Breakdown): MassSave runs new construction buildings of four units or fewer through its single-family and townhome track, and that track is all-electric only. A home that heats with gas, or that makes its hot water with gas, earns nothing here no matter how far the envelope beats code. The gas boiler and the hot water it feeds are what close the door, so the money turns on the mechanical package rather than on the score. Every incentive dollar in this study comes from the all-electric designs.
- IMPORTANT: The rule reads on the whole home, not on one appliance, and there is no partial credit. Putting a gas boiler or gas water heating back into an otherwise all-electric design removes the full per-home rebate for that building.
- IMPORTANT: The four-unit line is drawn per building, not per project. A site of duplexes stays on the single-family and townhome track and its all-electric rule however many buildings are built, which is why a gas mechanical package costs the same rebate on every one of them.

Path Comparison - Net Cost Summary

Path	Total Cost $/sf	Total Incentives $/sf	Net $/sf	OpEx Factor
NEXTGEN	$42.02	$7.00	$35.39	1.01
HERS40-ELECTRIC	$46.19	$7.12	$39.54	1.01
HERS40-GAS	$48.47	$0.00	$48.84	1.01

Path Comparison - Envelope

Item	Path	Detailed Specifications	Cost $/sf	Incentive $/sf	Net $/sf	OpEx
Exterior Walls	HERS40-ELECTRIC	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-10 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).	$7.72	$0.00	$7.72	0.95
	HERS40-GAS	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-10 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).	$7.72	$0.00	$7.72	0.95
	NEXTGEN	≥ R-21 cavity insulation (2x6 @ 16" o.c.) with ≥ R-9 continuous exterior insulation. Walls to the unconditioned garage: ≥ R-21 cavity insulation (2x6 @ 16" o.c.).	$7.61	$0.00	$7.61	0.95
Below Grade Walls	HERS40-ELECTRIC	N/A	$0.00	$0.00	$0.00	1.00
	HERS40-GAS	N/A	$0.00	$0.00	$0.00	1.00
	NEXTGEN	N/A	$0.00	$0.00	$0.00	1.00
Corridor Walls	HERS40-ELECTRIC	N/A	$0.00	$0.00	$0.00	1.00
	HERS40-GAS	N/A	$0.00	$0.00	$0.00	1.00
	NEXTGEN	N/A	$0.00	$0.00	$0.00	1.00
Slab	HERS40-ELECTRIC	≥ R-20 perimeter insulation, 2 ft deep, at the interior face of the slab edge, plus ≥ R-20 under-slab insulation, 2 ft wide; provides a full thermal break.	$0.86	$0.00	$0.86	0.90
	HERS40-GAS	≥ R-20 perimeter insulation, 2 ft deep, at the interior face of the slab edge, plus ≥ R-20 under-slab insulation, 2 ft wide; provides a full thermal break.	$0.86	$0.00	$0.86	0.90
	NEXTGEN	≥ R-20 perimeter insulation, 2 ft deep, at the interior face of the slab edge, plus ≥ R-20 under-slab insulation, 2 ft wide; provides a full thermal break.	$0.86	$0.00	$0.86	0.90
Floor Over Unconditioned Space	HERS40-ELECTRIC	N/A	$0.00	$0.00	$0.00	1.00
	HERS40-GAS	N/A	$0.00	$0.00	$0.00	1.00
	NEXTGEN	N/A	$0.00	$0.00	$0.00	1.00
Floor Over Garage	HERS40-ELECTRIC	≥ R-30 cavity insulation.	$0.04	$0.00	$0.04	0.90
	HERS40-GAS	≥ R-30 cavity insulation.	$0.04	$0.00	$0.04	0.90
	NEXTGEN	≥ R-30 cavity insulation.	$0.04	$0.00	$0.04	0.90
Floor Over Podium	HERS40-ELECTRIC	N/A	$0.00	$0.00	$0.00	1.00
	HERS40-GAS	N/A	$0.00	$0.00	$0.00	1.00
	NEXTGEN	N/A	$0.00	$0.00	$0.00	1.00
Rim Joists	HERS40-ELECTRIC	≥ R-21 rim/band insulation at floor transitions.	$0.20	$0.00	$0.20	0.95
	HERS40-GAS	≥ R-21 rim/band insulation at floor transitions.	$0.20	$0.00	$0.20	0.95
	NEXTGEN	≥ R-21 rim/band insulation at floor transitions.	$0.20	$0.00	$0.20	0.95
Roof	HERS40-ELECTRIC	Vented attic: ≥ R-60 insulation.	$1.20	$0.00	$1.20	1.00
	HERS40-GAS	Vented attic: ≥ R-60 insulation.	$1.20	$0.00	$1.20	1.00
	NEXTGEN	Vented attic: ≥ R-49 insulation.	$1.07	$0.00	$1.07	1.00
Windows & Glass Doors	HERS40-ELECTRIC	High performance, U ≤ 0.18 / SHGC ≤ 0.18.	$13.88	$0.00	$13.88	1.00
	HERS40-GAS	High performance, U ≤ 0.18 / SHGC ≤ 0.18.	$13.88	$0.00	$13.88	1.00
	NEXTGEN	High performance, U ≤ 0.25 / SHGC ≤ 0.25.	$10.43	$0.00	$10.43	1.00
Doors	HERS40-ELECTRIC	Opaque door, U ≤ 0.20 (R-5.0).	$0.35	$0.00	$0.35	0.95
	HERS40-GAS	Opaque door, U ≤ 0.20 (R-5.0).	$0.35	$0.00	$0.35	0.95
	NEXTGEN	Opaque door, U ≤ 0.20 (R-5.0).	$0.35	$0.00	$0.35	0.95
Air Sealing	HERS40-ELECTRIC	≤ 1.5 ACH50; tested.	$2.10	$0.00	$2.10	0.95
	HERS40-GAS	≤ 1.5 ACH50; tested.	$2.10	$0.00	$2.10	0.95
	NEXTGEN	≤ 1.5 ACH50; tested.	$2.10	$0.00	$2.10	0.95

Path Comparison - Mechanical

Item	Path	Detailed Specifications	Cost $/sf	Incentive $/sf	Net $/sf	OpEx
HVAC	HERS40-ELECTRIC	Ducted air-source heat pump (as modeled); SEER2 ≥ 17.5; HSPF2 ≥ 10.5. See HVAC Design Loads.	$6.34	$0.00	$6.34	1.15
	HERS40-GAS	Natural gas boiler (as modeled); AFUE ≥ 96; cooling by a separate system, cooling only; SEER2 ≥ 15.2. See HVAC Design Loads.	$8.63	$0.00	$8.63	1.10
	NEXTGEN	Ducted air-source heat pump (as modeled); SEER2 ≥ 17.5; HSPF2 ≥ 10.5; 5 kW electric heat kit on every four-bedroom unit. See HVAC Design Loads.	$6.38	$0.00	$6.38	1.15
Ductwork	HERS40-ELECTRIC	Supply and return ducts in attic under insulation poorly vented insulated to code minimum; ducts in conditioned space insulated to code minimum.	$2.08	$0.00	$2.08	1.00
	HERS40-GAS	Supply and return ducts in attic under insulation poorly vented insulated to code minimum; ducts in conditioned space insulated to code minimum.	$2.08	$0.00	$2.08	1.00
	NEXTGEN	Supply and return ducts in attic under insulation poorly vented insulated to code minimum; ducts in conditioned space insulated to code minimum.	$2.08	$0.00	$2.08	1.00
Duct Sealing	HERS40-ELECTRIC	≤ greater of 40 CFM25 or 4 CFM25 per 100 sqft of conditioned floor area; tested at rough-in, after the HVAC is installed.	$0.43	$0.00	$0.43	1.00
	HERS40-GAS	≤ greater of 40 CFM25 or 4 CFM25 per 100 sqft of conditioned floor area; tested at rough-in, after the HVAC is installed.	$0.43	$0.00	$0.43	1.00
	NEXTGEN	≤ greater of 40 CFM25 or 4 CFM25 per 100 sqft of conditioned floor area; tested at rough-in, after the HVAC is installed.	$0.43	$0.00	$0.43	1.00
HVAC Grading	HERS40-ELECTRIC	Fan Flow Test: Grade I Watt Draw Test: Grade I Refrigerant Charge: Grade I HVAC installer must provide photo of the digital refrigerant scale showing the amount charged, with the tank on the scale and hoses connected to the outdoor unit, along with a photo of the outdoor unit's data plate.	$0.00	$0.00	$0.00	1.00
	HERS40-GAS	Fan Flow Test: Grade I Watt Draw Test: Grade I Refrigerant Charge: Grade I HVAC installer must provide photo of the digital refrigerant scale showing the amount charged, with the tank on the scale and hoses connected to the outdoor unit, along with a photo of the outdoor unit's data plate.	$0.00	$0.00	$0.00	1.00
	NEXTGEN	Fan Flow Test: Grade I Watt Draw Test: Grade I Refrigerant Charge: Grade I HVAC installer must provide photo of the digital refrigerant scale showing the amount charged, with the tank on the scale and hoses connected to the outdoor unit, along with a photo of the outdoor unit's data plate.	$0.00	$0.00	$0.00	1.00
Mechanical Ventilation	HERS40-ELECTRIC	In-unit ERV 3-bedroom: 110 CFM, ≥ 81% ASRE 4-bedroom: 130 CFM, ≥ 79% ASRE	$1.05	$0.00	$1.05	1.20
	HERS40-GAS	In-unit ERV 3-bedroom: 110 CFM, ≥ 81% ASRE 4-bedroom: 130 CFM, ≥ 79% ASRE	$1.05	$0.00	$1.05	1.20
	NEXTGEN	In-unit ERV 3-bedroom: 110 CFM, ≥ 81% ASRE 4-bedroom: 130 CFM, ≥ 79% ASRE	$1.05	$0.00	$1.05	1.20
Local Mechanical Exhaust	HERS40-ELECTRIC	Bathroom(s): at least 50 CFM intermittent and up to 3.0 sones, or at least 20 CFM continuous and up to 2.0 sones. Kitchen(s): at least 100 CFM intermittent and up to 3.0 sones, or continuous at 5 ACH. Both: exhaust directly outdoors with ENERGY STAR certified fans. A balanced ERV or HRV serving the space may satisfy this requirement.	$0.50	$0.00	$0.50	1.05
	HERS40-GAS	Bathroom(s): at least 50 CFM intermittent and up to 3.0 sones, or at least 20 CFM continuous and up to 2.0 sones. Kitchen(s): at least 100 CFM intermittent and up to 3.0 sones, or continuous at 5 ACH. Both: exhaust directly outdoors with ENERGY STAR certified fans. A balanced ERV or HRV serving the space may satisfy this requirement.	$0.50	$0.00	$0.50	1.05
	NEXTGEN	Bathroom(s): at least 50 CFM intermittent and up to 3.0 sones, or at least 20 CFM continuous and up to 2.0 sones. Kitchen(s): at least 100 CFM intermittent and up to 3.0 sones, or continuous at 5 ACH. Both: exhaust directly outdoors with ENERGY STAR certified fans. A balanced ERV or HRV serving the space may satisfy this requirement.	$0.50	$0.00	$0.50	1.05
Thermostats	HERS40-ELECTRIC	Programmable thermostat (as modeled).	$0.04	$0.00	$0.04	1.05
	HERS40-GAS	Programmable thermostat (as modeled).	$0.04	$0.00	$0.04	1.05
	NEXTGEN	Programmable thermostat (as modeled).	$0.04	$0.00	$0.04	1.05

Path Comparison - Plumbing & Appliances

Item	Path	Detailed Specifications	Cost $/sf	Incentive $/sf	Net $/sf	OpEx
DHW	HERS40-ELECTRIC	3-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 4; 65 gal 4-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 4; 80 gal	$1.53	$0.00	$1.53	1.20
	HERS40-GAS	Gas tankless water heater (as modeled); UEF ≥ 0.96.	$1.95	$0.00	$1.95	1.15
	NEXTGEN	3-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 3.5; 65 gal 4-Bedroom: Heat pump water heater (HPWH) (as modeled); UEF ≥ 3.5; 80 gal	$1.42	$0.00	$1.42	1.20
DHW Piping	HERS40-ELECTRIC	Supply piping insulated to ≥ R-3.	$0.36	$0.00	$0.36	0.95
	HERS40-GAS	Supply piping insulated to ≥ R-3.	$0.36	$0.00	$0.36	0.95
	NEXTGEN	Supply piping insulated to ≥ R-3.	$0.36	$0.00	$0.36	0.95
Water Fixtures	HERS40-ELECTRIC	WaterSense certified (Lavatory ≤ 1.2 GPM; Shower ≤ 2.0 GPM; Kitchen ≤ 2.2 GPM).	$0.89	$0.00	$0.89	1.00
	HERS40-GAS	WaterSense certified (Lavatory ≤ 1.2 GPM; Shower ≤ 2.0 GPM; Kitchen ≤ 2.2 GPM).	$0.89	$0.00	$0.89	1.00
	NEXTGEN	WaterSense certified (Lavatory ≤ 1.2 GPM; Shower ≤ 2.0 GPM; Kitchen ≤ 2.2 GPM).	$0.89	$0.00	$0.89	1.00
Refrigerator	HERS40-ELECTRIC	≤ 600 kWh/yr; electric.	$0.38	$0.00	$0.38	1.10
	HERS40-GAS	≤ 600 kWh/yr; electric.	$0.38	$0.00	$0.38	1.10
	NEXTGEN	≤ 600 kWh/yr; electric.	$0.38	$0.00	$0.38	1.10
Dishwasher	HERS40-ELECTRIC	≤ 240 kWh/yr; electric.	$0.21	$0.00	$0.21	1.10
	HERS40-GAS	≤ 240 kWh/yr; electric.	$0.21	$0.00	$0.21	1.10
	NEXTGEN	≤ 240 kWh/yr; electric.	$0.21	$0.00	$0.21	1.10
Clothes Washer	HERS40-ELECTRIC	IMEF ≥ 2.06; IWF ≤ 4.2; ≤ 152 kWh/yr; electric.	$0.25	$0.00	$0.25	1.10
	HERS40-GAS	IMEF ≥ 2.06; IWF ≤ 4.2; ≤ 152 kWh/yr; electric.	$0.25	$0.00	$0.25	1.10
	NEXTGEN	IMEF ≥ 2.06; IWF ≤ 4.2; ≤ 152 kWh/yr; electric.	$0.25	$0.00	$0.25	1.10
Clothes Dryer	HERS40-ELECTRIC	Heat pump dryer; ventless; CEF ≥ 8.5.	$0.57	$0.00	$0.57	1.00
	HERS40-GAS	Standard electric dryer; vented; CEF ≥ 3.93.	$0.27	$0.00	$0.27	1.00
	NEXTGEN	Standard electric dryer; vented; CEF ≥ 3.93.	$0.27	$0.00	$0.27	1.00
Stove / Oven	HERS40-ELECTRIC	Electric induction cooktop; convection oven.	$0.39	$0.12	$0.27	1.05
	HERS40-GAS	Electric range.	$0.28	$0.00	$0.28	1.00
	NEXTGEN	Electric range.	$0.28	$0.00	$0.28	1.00

Path Comparison - Electrical

Item	Path	Detailed Specifications	Cost $/sf	Incentive $/sf	Net $/sf	OpEx
Lighting	HERS40-ELECTRIC	≥ 100% high-efficacy (LED).	$4.00	$0.00	$4.00	0.85
	HERS40-GAS	≥ 100% high-efficacy (LED).	$4.00	$0.00	$4.00	0.85
	NEXTGEN	≥ 100% high-efficacy (LED).	$4.00	$0.00	$4.00	0.85
Solar Ready	HERS40-ELECTRIC	Reserve an unobstructed rooftop solar-ready zone (at least 300 sq ft; 150 sq ft for small townhouses) with structural capacity, a conduit pathway, and reserved electrical-panel space. Waived if solar is already installed or the roof is heavily shaded.	$0.30	$0.00	$0.30	1.00
	HERS40-GAS	Reserve an unobstructed rooftop solar-ready zone (at least 300 sq ft; 150 sq ft for small townhouses) with structural capacity, a conduit pathway, and reserved electrical-panel space. Waived if solar is already installed or the roof is heavily shaded.	$0.30	$0.00	$0.30	1.00
	NEXTGEN	Reserve an unobstructed rooftop solar-ready zone (at least 300 sq ft; 150 sq ft for small townhouses) with structural capacity, a conduit pathway, and reserved electrical-panel space. Waived if solar is already installed or the roof is heavily shaded.	$0.30	$0.00	$0.30	1.00
EV Ready	HERS40-ELECTRIC	One 50-amp Level II EV-ready circuit per dwelling unit.	$0.33	$0.00	$0.33	1.00
	HERS40-GAS	One 50-amp Level II EV-ready circuit per dwelling unit.	$0.33	$0.00	$0.33	1.00
	NEXTGEN	One 50-amp Level II EV-ready circuit per dwelling unit.	$0.33	$0.00	$0.33	1.00
HPWH Ready	HERS40-ELECTRIC	N/A	$0.00	$0.00	$0.00	1.00
	HERS40-GAS	N/A	$0.00	$0.00	$0.00	1.00
	NEXTGEN	N/A	$0.00	$0.00	$0.00	1.00

Path Comparison - Soft Costs & Whole-Building Incentives

Item	Path	Detailed Specifications	Cost $/sf	Incentive $/sf	Net $/sf	OpEx
Paperwork & Modeling	HERS40-ELECTRIC	ENERGY STAR energy model to the ERI target, the ENERGY STAR design-review checklist, and an HVAC design report. Plus ENERGY STAR NextGen documentation: all-electric equipment and EV-charging provisions.	$0.06	$7.00	-$6.94	1.00
	HERS40-GAS	ENERGY STAR energy model to the ERI target, the ENERGY STAR design-review checklist, and an HVAC design report.	$0.05	$0.00	$0.05	1.00
	NEXTGEN	ENERGY STAR energy model to the ERI target, the ENERGY STAR design-review checklist, and an HVAC design report. Plus ENERGY STAR NextGen documentation: all-electric equipment and EV-charging provisions.	$0.06	$7.00	-$6.94	1.00
Testing & Verification	HERS40-ELECTRIC	ENERGY STAR field verification: pre-drywall and final inspections, blower-door and duct-leakage tests, ventilation airflow, and HVAC installation grading. Plus ENERGY STAR NextGen verification: all-electric equipment and EV-charging infrastructure.	$0.13	$0.00	$0.13	1.00
	HERS40-GAS	ENERGY STAR field verification: pre-drywall and final inspections, blower-door and duct-leakage tests, ventilation airflow, and HVAC installation grading.	$0.12	$0.00	$0.12	1.00
	NEXTGEN	ENERGY STAR field verification: pre-drywall and final inspections, blower-door and duct-leakage tests, ventilation airflow, and HVAC installation grading. Plus ENERGY STAR NextGen verification: all-electric equipment and EV-charging infrastructure.	$0.13	$0.00	$0.13	1.00