CS58 Energy Code Feasibility Study in Lexington, Massachusetts
Energy code feasibility study for a 31-unit Low-Rise Multifamily in Massachusetts. Compares multiple design paths. Recommended: CONTINUOUS. View full study.
- Study Type
- Energy Code Feasibility Study
- State
- Massachusetts
- Units
- 31
- Building Type
- Low-Rise Multifamily
- Fuel Type
- All-Electric
- Recommended Path
- CONTINUOUS
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
- Lexington, MA 02420
- 31 Units | 28,458 sqft
- New Construction | Low-Rise Multifamily
- All-Electric | Specialized Opt-In | HERS ≤ 45 OR HERS ≤ 48 (GWP)| ESTAR MFNC v1.2 (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.
Path Summaries
CONTINUOUS (Recommended): An all-electric HERS/ERI path with ENERGY STAR certification. The system pairs a ducted cold-climate heat pump (SEER2 17 / HSPF2 10) with metal ducts run inside conditioned space, R-21 cavity plus R-5 continuous exterior insulation walls, and an R-60 roof. The continuous insulation layer covers the framing so the wall retains close to its full rated value rather than losing heat through every stud, and the ducted system delivers even, concealed conditioning to every room, including bedrooms behind closed doors. This path also carries the best window package of the three (U-0.25). It is recommended because it matches the ducted distribution the intake form requested and pairs that system with the strongest envelope and glazing of the three paths.
SPRAY (Great Alternative): An all-electric HERS/ERI path with ENERGY STAR certification. It uses a ductless cold-climate heat pump (SEER2 20 / HSPF2 10), which eliminates all ductwork, duct sealing, and duct testing, and fills the 2x6 wall cavity with a hybrid of 3 inches closed-cell and 2.5 inches open-cell spray foam (R-30) in place of exterior continuous insulation. Dropping the ducts more than offsets the higher cost of the spray-foam wall, and the more efficient ductless equipment reduces energy use further, making this the lowest net-cost and most efficient path of the three. The roof and windows match CONTINUOUS. It is not recommended here only because the intake form requested ducted distribution and ductless units require wall-mounted heads inside the units, but it is a strong choice worth revisiting if that preference is flexible, since it saves money and improves performance at the same time.
GWP: An all-electric HERS/ERI path with ENERGY STAR certification, built to minimize embodied carbon. It keeps the same ducted system and R-21 plus R-5 continuous insulation wall approach as CONTINUOUS, but constructs the envelope from carbon-storing materials: dense-pack cellulose cavities, wood fiberboard continuous insulation, a cellulose-filled rim band, low-GWP XPS under the slab, and lower-density roof foam. These choices target the embodied-carbon credit available under the Massachusetts specialized code, and the path includes the additional documentation required to claim it. To manage first cost, windows step down slightly to U-0.30 and the roof to R-49. This path is not the right fit for a developer focused purely on operating cost, but it is the preferred choice if reducing the building’s upfront carbon footprint and capturing the embodied-carbon code credit are priorities.
Code Path
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: $88,350 - $134,850
MassSave Multifamily Low Rise Program Energy Star Tier ($77,500) (Program Breakdown): You get this rebate for having your building(s) certified for the Energy Star MFNC v1.2 program. This requires pre-approval via an application to be submitted before construction starts. 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.
Wi-Fi Connected Thermostat Adder ($3,100): A MassSave market transformation adder of $100 per unit for installing a Wi-Fi connected thermostat 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.
In-Unit Heat Pump Water Heater Adder ($7,750): A MassSave market transformation adder of $250 per unit for installing a heat-pump water heater 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.
Induction Cooktop Adder ($7,750): 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.
DOER Alternative Energy Credits (Program Breakdown) ($0 - $46,500): This rebate is received for installing APS eligible air source heat pumps (click here for the list). There is an extensive process to get this incentive. It comes in the form of a check approximately 6-12 months after the heat pumps are installed and fully operational.
IMPORTANT: Although an estimate is provided, this incentive can vary widely typically between $300-1,500 per heat pump. It’s based on expected kWh usage of the system as well as the market value of the alternative energy credits when sold.
Recommended Design
| Item | Detailed Specifications |
|---|---|
| Exterior Walls | R-21 cavity + R-5 continuous insulation. |
| Slab | R-10 fully insulated slab. |
| Floor Over Garage | N/A |
| Rim Joists | Seal interior rim cavity with 3.5" closed-cell spray foam (R-21). |
| Roof | R-60 closed cell spray foam insulation. |
| Windows & Glass Doors | Double pane, U-0.25 / SHGC 0.25; |
| Doors | Opaque: R-4.75. |
| Air Sealing | Units: ≤ 0.27 CFM50 per sqft enclosure space (Air sealing protocol) (Emergency Air Sealing) |
| HVAC | Ducted mini-split cold-climate heat pump; SEER2 17; HSPF2 10; ENERGY STAR CCHP (2 Bedroom Unit) (3 Bedroom Unit). *Double check sizing with mechanical engineers, 3 bedroom units may be able to use 2 ton units as well. |
| Ductwork | Supply and return ductwork in conditioned space, metal ducts (not ductboard). |
| Duct Sealing | The greater of 8 CFM25/100 ft² conditioned floor area or 80 CFM25 to outside (duct sealing protocol). |
| HVAC Grading | Fan Flow Test: N/A Watt Draw Test: N/A Refrigerant Charge: N/A |
| Mechanical Ventilation | Ducted or Ductless ERV; 50 CFM; ≥ 83% recovery efficiency (Ducted) (Ductless). |
| Local Mechanical Exhaust | Bathroom(s): ≥ 50 CFM intermittent & ≤ 3.0 sones OR ≥ 20 CFM continuous & ≤ 2.0 sones. Kitchen(s): ≥ 100 CFM intermittent & ≤ 3.0 sones OR continuous, ≥ 5 ACH. Both: Exhaust directly outdoors, ENERGY STAR certified. |
| Thermostats | Programmable Thermostat (product rec). |
| DHW | 2BR: HPWH; UEF 3.80; 50 gal; in-unit (Product Rec). 3BR: HPWH; UEF 3.80; 65 gal; in-unit (Product Rec). *Must be located in a conditioned corridor. |
| DHW Piping | Supply piping insulated to R-3 minimum; Max length of hot water supply piping: 38 ft. |
| Water Fixtures | WaterSense Certified Fixtures (Lavatory: ≤1.2 GPM; Shower: ≤2.0 GPM; Kitchen: ≤2.2 GPM). |
| Refrigerator | All: ≤ 450 kWh annual usage; ENERGY STAR; Electric (Product Rec). |
| Dishwasher | All: ≤ 240 kWh annual usage; ENERGY STAR; Electric (Product Rec). |
| Clothes Washer | All: ENERGY STAR; Electric (Product Rec). |
| Clothes Dryer | All: Standard electric dryer; Vented; ENERGY STAR (Product Rec). |
| Stove / Oven | Standard electric range; Induction cooktop; Convection oven (Product Rec). |
| Lighting | 100% high-efficacy (LED). |
| Solar Ready | Applicability: All new R-use buildings (including R-2 multifamily) with ≥600 sqft of roof area oriented 110°–270° of true north Minimum Area: Solar-ready zone ≥300 sqft, exclusive of MA Fire Code access/setback areas Zone Dimensions: May be multiple areas; each area must be ≥5 feet wide and ≥80 sqft (exclusive of fire code setbacks) Obstructions/Shading: Zone must be free of vents, chimneys, and roof equipment; set back from permanently affixed objects (south, east, west) by ≥2x the object's height above the nearest roof surface point Roof Penetration: For roofs with slope ≤8%, provide a capped penetration sleeve with min. 1-1/4" inside diameter Structural: Roof dead and live load documentation on construction documents confirming structure supports a future solar system Interconnection Pathway: Construction documents shall show conduit/plumbing pathways from solar-ready zone to electrical panel (or service hot water system) Panel Reserved Space: Dual-pole breaker space reserved in electrical panel for future solar system Documentation Certificate: Permanent certificate posted near electrical distribution panel indicating solar-ready zone and accommodated system size |
| EV Ready | Minimum Circuit: At least 20% of all parking spaces served with a 40-amp, 208/240V branch circuit (min. 9.6 kVA) for AC Level II charging Termination: Circuit shall terminate in a NEMA receptacle or SAE J1772/J3400 connector within 6 feet of each EV ready space Labeling: Circuit labeled EV READY in service/subpanel directory; termination location at parking space also marked EV READY Conductor Sizing: Sized and installed per Massachusetts Electrical Code (527 CMR 12.00) ALMS Option (Exception 3): May comply with C405.13 - ALMS may share circuits per Table C405.13.1 (40A/2 spaces, 60A/4 spaces, 80A/8 spaces); construction documents must include amperage, wiring schematics, ALMS details, and load calculations per C405.13.2 Level I Substitution: Level II spaces may be substituted at a ratio of 3 Level I (20A, 120V) per 1 Level II required |
| HPWH Ready | N/A |
| Paperwork & Modeling | HERS/ERI energy model, 2021 IECC checklists, ENERGY STAR checklists, incentive documentation. |
| Testing & Verification | Unit Blower Door Test, Duct Leakage Testing, Mechanical Ventilation Testing, Predrywall & Final Inspection. |
Exterior Wall Assembly (Option 1)
Exterior Wall Assembly (Option 2)
Exterior Wall (Option 3)
Rim Joist (Option 1)
Rim Joist (Option 2)
Rim Joist (Option 3)
Roof (Option 1)
Roof (Option 2)
Slab Edge
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
CONTINUOUS/SPRAY: $96,100 - $142,600
MassSave Multifamily Low Rise Program Energy Star Tier ($77,500) (Program Breakdown): You get this rebate for having your building(s) certified for the Energy Star MFNC v1.2 program. This requires pre-approval via an application to be submitted before construction starts. 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.
Wi-Fi Connected Thermostat Adder ($3,100): A MassSave market transformation adder of $100 per unit for installing a Wi-Fi connected thermostat 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.
In-Unit Heat Pump Water Heater Adder ($7,750): A MassSave market transformation adder of $250 per unit for installing a heat-pump water heater 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.
Induction Cooktop Adder ($7,750): 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.
DOER Alternative Energy Credits (Program Breakdown) ($0 - $46,500): This rebate is received for installing APS eligible air source heat pumps (click here for the list). There is an extensive process to get this incentive. It comes in the form of a check approximately 6-12 months after the heat pumps are installed and fully operational.
IMPORTANT: Although an estimate is provided, this incentive can vary widely typically between $300-1,500 per heat pump. It’s based on expected kWh usage of the system as well as the market value of the alternative energy credits when sold.
GWP: $88,350 - $134,850
MassSave Multifamily Low Rise Program Energy Star Tier ($77,500) (Program Breakdown): You get this rebate for having your building(s) certified for the Energy Star MFNC v1.2 program. This requires pre-approval via an application to be submitted before construction starts. 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.
Wi-Fi Connected Thermostat Adder ($3,100): A MassSave market transformation adder of $100 per unit for installing a Wi-Fi connected thermostat 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.
In-Unit Heat Pump Water Heater Adder ($7,750): A MassSave market transformation adder of $250 per unit for installing a heat-pump water heater 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.
DOER Alternative Energy Credits (Program Breakdown) ($0 - $46,500): This rebate is received for installing APS eligible air source heat pumps (click here for the list). There is an extensive process to get this incentive. It comes in the form of a check approximately 6-12 months after the heat pumps are installed and fully operational.
IMPORTANT: Although an estimate is provided, this incentive can vary widely typically between $300-1,500 per heat pump. It’s based on expected kWh usage of the system as well as the market value of the alternative energy credits when sold.
Path Comparison - Net Cost Summary
| Path | Total Cost $/sf | Total Incentives $/sf | Net $/sf | OpEx Factor | Worst HERS | Target HERS |
|---|---|---|---|---|---|---|
| CONTINUOUS | $48.70 | $3.37 | $45.80 | 1.01 | 43.19 | 45.00 |
| SPRAY | $46.30 | $3.37 | $43.45 | 1.01 | 43.87 | 45.00 |
| GWP | $48.05 | $3.10 | $45.57 | 1.01 | 45.86 | 48.00 |
Path Comparison - Envelope
| Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf | OpEx Factor |
|---|---|---|---|---|---|---|
| Exterior Walls | CONTINUOUS | R-21 cavity + R-5 continuous insulation. | $1.50 | $0.00 | $1.50 | 1.00 |
| SPRAY | R-30 3" closed-cell spray foam & 2.5" open-cell spray foam | $4.00 | $0.00 | $4.00 | 0.95 | |
| GWP | R-21 cavity + R-5 continuous insulation (densepack cellulose & wood fiberboard 1.5"). | $1.85 | $0.00 | $1.85 | 1.00 | |
| Slab | CONTINUOUS | R-10 fully insulated slab. | $3.00 | $0.00 | $3.00 | 0.90 |
| SPRAY | R-10 fully insulated slab. | $3.00 | $0.00 | $3.00 | 0.90 | |
| GWP | R-10 fully insulated slab (Low GWP XPS). | $3.25 | $0.00 | $3.25 | 0.90 | |
| Floor Over Garage | CONTINUOUS | N/A | $0.00 | $0.00 | $0.00 | 1.00 |
| SPRAY | N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| GWP | N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| Rim Joists | CONTINUOUS | Seal interior rim cavity with 3.5" closed-cell spray foam (R-21). | $0.40 | $0.00 | $0.40 | 0.95 |
| SPRAY | Seal interior rim cavity with 3.5" closed-cell spray foam (R-21). | $0.40 | $0.00 | $0.40 | 0.95 | |
| GWP | Seal interior rim cavity with 5.5" densepack cellulose (R-21). | $0.35 | $0.00 | $0.35 | 1.00 | |
| Roof | CONTINUOUS | R-60 closed cell spray foam insulation. | $2.50 | $0.00 | $2.50 | 0.90 |
| SPRAY | R-60 closed cell spray foam insulation. | $2.50 | $0.00 | $2.50 | 0.90 | |
| GWP | R-49 closed cell spray foam insulation (not high density). | $2.10 | $0.00 | $2.10 | 0.95 | |
| Windows & Glass Doors | CONTINUOUS | Double pane, U-0.25 / SHGC 0.25; | $7.00 | $0.00 | $7.00 | 1.00 |
| SPRAY | Double pane, U-0.25 / SHGC 0.25; | $7.00 | $0.00 | $7.00 | 1.00 | |
| GWP | Double pane, U-0.30 / SHGC 0.30; | $6.50 | $0.00 | $6.50 | 1.00 | |
| Doors | CONTINUOUS | Opaque: R-4.75. | $0.50 | $0.00 | $0.50 | 1.00 |
| SPRAY | Opaque: R-4.75. | $0.50 | $0.00 | $0.50 | 1.00 | |
| GWP | Opaque: R-4.75. | $0.50 | $0.00 | $0.50 | 1.00 | |
| Air Sealing | CONTINUOUS | Units: ≤ 0.27 CFM50 per sqft enclosure space (Air sealing protocol) (Emergency Air Sealing) | $0.45 | $0.00 | $0.45 | 0.90 |
| SPRAY | Units: ≤ 0.27 CFM50 per sqft enclosure space (Air sealing protocol) (Emergency Air Sealing) | $0.45 | $0.00 | $0.45 | 0.90 | |
| GWP | Units: ≤ 0.27 CFM50 per sqft enclosure space; (Air sealing protocol) (Emergency Air Sealing) | $0.45 | $0.00 | $0.45 | 0.90 |
Path Comparison - Mechanical
| Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf | OpEx Factor |
|---|---|---|---|---|---|---|
| HVAC | CONTINUOUS | Ducted mini-split cold-climate heat pump; SEER2 17; HSPF2 10; ENERGY STAR CCHP (2 Bedroom Unit) (3 Bedroom Unit). *Double check sizing with mechanical engineers, 3 bedroom units may be able to use 2 ton units as well. | $14.60 | $0.00 | $14.60 | 1.15 |
| SPRAY | Ductless mini-split cold-climate heat pump; SEER2 20; HSPF2 10; ENERGY STAR CCHP (2 Bedroom Unit) (3 Bedroom Unit). *Double check sizing with mechanical engineers, 3 bedroom units may be able to use 2 ton units as well. | $12.00 | $0.00 | $12.00 | 1.10 | |
| GWP | Ducted mini-split cold-climate heat pump; SEER2 17; HSPF2 10; ENERGY STAR CCHP (2 Bedroom Unit) (3 Bedroom Unit). *Double check sizing with mechanical engineers, 3 bedroom units may be able to use 2 ton units as well. | $14.60 | $0.00 | $14.60 | 1.15 | |
| Ductwork | CONTINUOUS | Supply and return ductwork in conditioned space, metal ducts (not ductboard). | $2.00 | $0.00 | $2.00 | 0.95 |
| SPRAY | N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| GWP | Supply and return ductwork in conditioned space, metal ducts (not ductboard). | $2.00 | $0.00 | $2.00 | 0.95 | |
| Duct Sealing | CONTINUOUS | The greater of 8 CFM25/100 ft² conditioned floor area or 80 CFM25 to outside (duct sealing protcol). | $0.25 | $0.00 | $0.25 | 0.90 |
| SPRAY | N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| GWP | The greater of 8 CFM25/100 ft² conditioned floor area or 80 CFM25 to outside (duct sealing protcol). | $0.25 | $0.00 | $0.25 | 0.90 | |
| HVAC Grading | CONTINUOUS | Fan Flow Test: N/A Watt Draw Test: N/A Refrigerant Charge: N/A | $0.00 | $0.00 | $0.00 | 1.00 |
| SPRAY | Fan Flow Test: N/A Watt Draw Test: N/A Refrigerant Charge: N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| GWP | Fan Flow Test: N/A Watt Draw Test: N/A Refrigerant Charge: N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| Mechanical Ventilation | CONTINUOUS | Ducted or Ductless ERV; 50 CFM; ≥ 83% recovery efficiency (Ducted) (Ductless). | $3.00 | $0.00 | $3.00 | 1.15 |
| SPRAY | Ducted or Ductless ERV; 50 CFM; ≥ 83% recovery efficiency (Ducted) (Ductless). | $3.00 | $0.00 | $3.00 | 1.15 | |
| GWP | Ducted or Ductless ERV; 50 CFM; ≥ 83% recovery efficiency (Ducted) (Ductless). | $3.00 | $0.00 | $3.00 | 1.15 | |
| Local Mechanical Exhaust | CONTINUOUS | Bathroom(s): ≥ 50 CFM intermittent & ≤ 3.0 sones OR ≥ 20 CFM continuous & ≤ 2.0 sones. Kitchen(s): ≥ 100 CFM intermittent & ≤ 3.0 sones OR continuous, ≥ 5 ACH. Both: Exhaust directly outdoors, ENERGY STAR certified. | $1.50 | $0.00 | $1.50 | 1.05 |
| SPRAY | Bathroom(s): ≥ 50 CFM intermittent & ≤ 3.0 sones OR ≥ 20 CFM continuous & ≤ 2.0 sones. Kitchen(s): ≥ 100 CFM intermittent & ≤ 3.0 sones OR continuous, ≥ 5 ACH. Both: Exhaust directly outdoors, ENERGY STAR certified. | $1.50 | $0.00 | $1.50 | 1.05 | |
| GWP | Bathroom(s): ≥ 50 CFM intermittent & ≤ 3.0 sones OR ≥ 20 CFM continuous & ≤ 2.0 sones. Kitchen(s): ≥ 100 CFM intermittent & ≤ 3.0 sones OR continuous, ≥ 5 ACH. Both: Exhaust directly outdoors, ENERGY STAR certified. | $1.50 | $0.00 | $1.50 | 1.05 | |
| Thermostats | CONTINUOUS | Programmable Thermostat (product rec). | $0.00 | $0.11 | -$0.11 | 1.00 |
| SPRAY | Programmable Thermostat (product rec). | $0.00 | $0.11 | -$0.11 | 1.00 | |
| GWP | Programmable Thermostat (product rec). | $0.00 | $0.11 | -$0.11 | 1.00 |
Path Comparison - Plumbing & Appliances
| Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf | OpEx Factor |
|---|---|---|---|---|---|---|
| DHW | CONTINUOUS | 2BR: HPWH; UEF 3.80; 50 gal; in-unit (Product Rec). 3BR: HPWH; UEF 3.80; 65 gal; in-unit (Product Rec). *Located in-unit | $2.85 | $0.27 | $2.58 | 1.20 |
| SPRAY | 2BR: HPWH; UEF 3.80; 50 gal; in-unit (Product Rec). 3BR: HPWH; UEF 3.80; 65 gal; in-unit (Product Rec). *Located in-unit | $2.85 | $0.27 | $2.58 | 1.20 | |
| GWP | 2BR: HPWH; UEF 3.80; 50 gal; in-unit (Product Rec). 3BR: HPWH; UEF 3.80; 65 gal; in-unit (Product Rec). *Located in-unit | $2.85 | $0.27 | $2.58 | 1.20 | |
| DHW Piping | CONTINUOUS | Supply piping insulated to R-3 minimum; Max length of hot water supply piping: 38 ft. | $0.15 | $0.00 | $0.15 | 1.00 |
| SPRAY | Supply piping insulated to R-3 minimum; Max length of hot water supply piping: 38 ft. | $0.15 | $0.00 | $0.15 | 1.00 | |
| GWP | Supply piping insulated to R-3 minimum; Max length of hot water supply piping: 38 ft. | $0.15 | $0.00 | $0.15 | 1.00 | |
| Water Fixtures | CONTINUOUS | WaterSense Certified Fixtures (Lavatory: ≤1.2 GPM; Shower: ≤2.0 GPM; Kitchen: ≤2.2 GPM). | $0.50 | $0.00 | $0.50 | 1.00 |
| SPRAY | WaterSense Certified Fixtures (Lavatory: ≤1.2 GPM; Shower: ≤2.0 GPM; Kitchen: ≤2.2 GPM). | $0.50 | $0.00 | $0.50 | 1.00 | |
| GWP | WaterSense Certified Fixtures (Lavatory: ≤1.2 GPM; Shower: ≤2.0 GPM; Kitchen: ≤2.2 GPM). | $0.50 | $0.00 | $0.50 | 1.00 | |
| Refrigerator | CONTINUOUS | All: ≤ 450 kWh annual usage; ENERGY STAR; Electric (Product Rec). | $0.75 | $0.00 | $0.75 | 1.05 |
| SPRAY | All: ≤ 550 kWh annual usage; ENERGY STAR; Electric (Product Rec). | $0.70 | $0.00 | $0.70 | 1.05 | |
| GWP | All: ≤ 550 kWh annual usage; ENERGY STAR; Electric (Product Rec). | $0.70 | $0.00 | $0.70 | 1.05 | |
| Dishwasher | CONTINUOUS | All: ≤ 240 kWh annual usage; ENERGY STAR; Electric (Product Rec). | $0.55 | $0.00 | $0.55 | 1.05 |
| SPRAY | All: ≤ 240 kWh annual usage; ENERGY STAR; Electric (Product Rec). | $0.55 | $0.00 | $0.55 | 1.05 | |
| GWP | All: ≤ 240 kWh annual usage; ENERGY STAR; Electric (Product Rec). | $0.55 | $0.00 | $0.55 | 1.05 | |
| Clothes Washer | CONTINUOUS | All: ENERGY STAR; Electric (Product Rec). | $0.60 | $0.00 | $0.60 | 1.10 |
| SPRAY | All: ENERGY STAR; Electric (Product Rec). | $0.60 | $0.00 | $0.60 | 1.10 | |
| GWP | All: ENERGY STAR; Electric (Product Rec). | $0.60 | $0.00 | $0.60 | 1.10 | |
| Clothes Dryer | CONTINUOUS | All: Standard electric dryer; Vented; ENERGY STAR (Product Rec). | $0.60 | $0.00 | $0.60 | 1.10 |
| SPRAY | All: Standard electric dryer; Vented; ENERGY STAR (Product Rec). | $0.60 | $0.00 | $0.60 | 1.10 | |
| GWP | All: Standard electric dryer; Vented; ENERGY STAR (Product Rec). | $0.60 | $0.00 | $0.60 | 1.10 | |
| Stove / Oven | CONTINUOUS | Standard electric range; Induction cooktop; Convection oven (Product Rec). | $0.85 | $0.27 | $0.58 | 1.05 |
| SPRAY | Standard electric range; Induction cooktop; Convection oven (Product Rec). | $0.85 | $0.27 | $0.58 | 1.05 | |
| GWP | Standard electric range; No induction; No convection (Product Rec). | $0.60 | $0.00 | $0.60 | 1.05 |
Path Comparison - Electrical
| Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf | OpEx Factor |
|---|---|---|---|---|---|---|
| Lighting | CONTINUOUS | 100% high-efficacy (LED). | $3.50 | $0.00 | $3.50 | 0.85 |
| SPRAY | 100% high-efficacy (LED). | $3.50 | $0.00 | $3.50 | 0.85 | |
| GWP | 100% high-efficacy (LED). | $3.50 | $0.00 | $3.50 | 0.85 | |
| Solar Ready | CONTINUOUS | Applicability: All new R-use buildings (including R-2 multifamily) with ≥600 sqft of roof area oriented 110°–270° of true north Minimum Area: Solar-ready zone ≥300 sqft, exclusive of MA Fire Code access/setback areas Zone Dimensions: May be multiple areas; each area must be ≥5 feet wide and ≥80 sqft (exclusive of fire code setbacks) Obstructions/Shading: Zone must be free of vents, chimneys, and roof equipment; set back from permanently affixed objects (south, east, west) by ≥2x the object's height above the nearest roof surface point Roof Penetration: For roofs with slope ≤8%, provide a capped penetration sleeve with min. 1-1/4" inside diameter Structural: Roof dead and live load documentation on construction documents confirming structure supports a future solar system Interconnection Pathway: Construction documents shall show conduit/plumbing pathways from solar-ready zone to electrical panel (or service hot water system) Panel Reserved Space: Dual-pole breaker space reserved in electrical panel for future solar system Documentation Certificate: Permanent certificate posted near electrical distribution panel indicating solar-ready zone and accommodated system size | $0.05 | $0.00 | $0.05 | 1.00 |
| SPRAY | Same as CONTINUOUS | $0.05 | $0.00 | $0.05 | 1.00 | |
| GWP | Same as CONTINUOUS | $0.05 | $0.00 | $0.05 | 1.00 | |
| EV Ready | CONTINUOUS | Minimum Circuit: At least 20% of all parking spaces served with a 40-amp, 208/240V branch circuit (min. 9.6 kVA) for AC Level II charging Termination: Circuit shall terminate in a NEMA receptacle or SAE J1772/J3400 connector within 6 feet of each EV ready space Labeling: Circuit labeled EV READY in service/subpanel directory; termination location at parking space also marked EV READY Conductor Sizing: Sized and installed per Massachusetts Electrical Code (527 CMR 12.00) ALMS Option (Exception 3): May comply with C405.13 - ALMS may share circuits per Table C405.13.1 (40A/2 spaces, 60A/4 spaces, 80A/8 spaces); construction documents must include amperage, wiring schematics, ALMS details, and load calculations per C405.13.2 Level I Substitution: Level II spaces may be substituted at a ratio of 3 Level I (20A, 120V) per 1 Level II required | $0.60 | $0.00 | $0.60 | 1.05 |
| SPRAY | Same as CONTINUOUS | $0.60 | $0.00 | $0.60 | 1.05 | |
| GWP | Same as CONTINUOUS | $0.60 | $0.00 | $0.60 | 1.05 | |
| HPWH Ready | CONTINUOUS | N/A | $0.00 | $0.00 | $0.00 | 1.00 |
| SPRAY | N/A | $0.00 | $0.00 | $0.00 | 1.00 | |
| GWP | N/A | $0.00 | $0.00 | $0.00 | 1.00 |
Path Comparison - Soft Costs
| Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf | OpEx Factor |
|---|---|---|---|---|---|---|
| Paperwork & Modeling | CONTINUOUS | HERS/ERI energy model, 2021 IECC checklists, ENERGY STAR checklists, incentive documentation. | $1.00 | $2.72 | -$1.72 | 1.00 |
| SPRAY | HERS/ERI energy model, 2021 IECC checklists, ENERGY STAR checklists, incentive documentation. | $1.00 | $2.72 | -$1.72 | 1.00 | |
| GWP | HERS/ERI energy model, 2021 IECC checklists, ENERGY STAR checklists, incentive documentation, Embodied Carbon Credit Paperwork. | $1.00 | $2.72 | -$1.72 | 1.00 | |
| Testing & Verification | CONTINUOUS | Unit Blower Door Test, Duct Leakage Testing, Mechanical Ventilation Testing, Predrywall & Final Inspection. | $0.00 | $0.00 | $0.00 | 1.00 |
| SPRAY | Unit Blower Door Test, Mechanical Ventilation Testing, Predrywall & Final Inspection. | $0.00 | $0.00 | $0.00 | 1.00 | |
| GWP | Unit Blower Door Test, Duct Leakage Testing, Mechanical Ventilation Testing, Predrywall & Final Inspection. | $0.00 | $0.00 | $0.00 | 1.00 |
Additional Design Considerations Not Represented In This Study
N/A