CS29 Energy Code Feasibility Study in Framingham, Massachusetts
Energy code feasibility study for a 46-unit 5-Story Building | 4 Residential stories over a podium. in Massachusetts. Compares multiple design paths. Recommended: Centralized Heat Pump Water Heater. View full study.
- Study Type
- Energy Code Feasibility Study
- State
- Massachusetts
- Units
- 46
- Building Type
- 5-Story Building | 4 Residential stories over a podium.
- Fuel Type
- All-Electric
- Recommended Path
- Centralized Heat Pump Water Heater
Goal
This report is designed to help project teams identify the most cost-effective approach to energy code compliance. The costs shown reflect only the efficiency measures required for each energy code path, not total construction costs, allowing a clear comparison of true performance and incentive differences between paths.
All estimates are grounded in real Massachusetts bid data, the Mass Save Energy Code Study, and RSMeans regional pricing benchmarks. This study provides a reliable framework for aligning incentives and assembly design, with all recommendations confirmed through detailed energy modeling and local code requirement documentation.
Project
- Framingham, MA 01702
- 46 Units | 56,800 sqft
- 5-Story Building | 4 Residential stories over a podium.
- New Construction | Stretch Code | HERS ≤ 45 | All Electric
Code & Paths
HERS (DESIGNED): This is for reference only to show what the current design has called out, the current design has the HERS scores in the 50s, while stretch code calls out for a HERS score of 45 or less.
HERS (ENVELOPE): In this example we leave the mechanical equipment as is and improve the exterior wall insulation to 2×6 R-34 spray foam + R-10 continuous insulation and by installing triple pane windows and glass doors that are U-0.18 / SHGC 0.25+. This path has no buffer with the worst case units ranging from a HERS score of 42-45.
HERS (EQUIPMENT): In this example we leave the envelope as is and improve the water heater to a heat pump water heater with a UEF of 3.83 or more. This path has a large buffer with the worst case units ranging from a HERS score of 36-42.
Incentives
Stretch Code - HERS (AS-DESIGNED): N/A
Stretch Code - HERS (ENVELOPE): $80,500
- Mass Save Multifamily High Rise New Construction - Base Tier: $46,000.
- Mass Save Multifamily High Rise New Construction - ENERGY STAR MFNC Tier: $80,500.
Stretch Code - HERS (EQUIPMENT): $92,000
- Mass Save Multifamily High Rise New Construction - Base Tier: $46,000.
- Mass Save Multifamily High Rise New Construction - ENERGY STAR MFNC Tier: $80,500.
- Mass Save In-Unit Heat Pump Water Heater: $11,500
Other Incentives That Aren’t Worth It
- Centralized Heat Pump Water Heater: Since hallway closets isolate the noise and cold air, we do not recommend the $66,200 premium for the central system.
- DOER Alternative Energy Certificates: There are no suitable ducted replacements off the approved heat pump list making this unavailable unless the project switched to ductless systems.
- DOE Zero Energy Ready Homes Certification: The $250 incentive doesn’t come close to offsetting the cost and complexity of the program.
- Induction Cooktop: Cost about $400 more than standard electric ranges, and with only a $250 incentive, you’d lose roughly $150.
- Split Heat Pump Water Heater: Cost about $3,000, roughly $1,200 more than a standard $1,800 unit, but with only a $750 incentive, the net loss is about $450.
- ENERGY STAR Certified Ground Source Heat Pump: Do not pursue Ground Source Heat Pumps for this specific site unless you can confirm (via a test bore and thermal conductivity test) that a "Hybrid" system (smaller borefield + roof-mounted cooling tower) is viable. Otherwise, the logistical complexity, cost, and schedule delay risk outweigh the operational savings.
- ENERGY STAR NextGen Certification: The certification increases the blower door test requirement from an ACH50 of 3.0 to an ACH50 of 1.5. The cost and complexity required to meet this doesn’t come close to the $250 per unit incentive given.
- High-rise Whole Building Infiltration Testing: The per unit benefit barely covers the cost to do this test and it certainly doesn’t cover the cost to comply with the whole building air sealing requirements.
Recommended Design - Units
Item | Detailed Specifications |
|---|---|
Exterior Walls | 2×6 R-21 batt + R-4 continuous insulation. |
Floor Over Unconditioned Space | R-30 cavity spray foam + R-20 continuous insulation. |
Rim Joists | 2×6 R-21 batt + R-4 continuous insulation. |
Roof | R-30 roof deck continuous insulation + R-13 spray foam in cavity. |
Windows | U-0.30 / SHGC 0.30-0.40 |
Doors | Glazed: U-0.30 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75); |
Air Sealing | Units: ≤3 ACH50; |
Space Conditioning | 1 Bed: Ducted split heat pump; SEER2 17.5; HSPF2 9; (Interior Unit) (Exterior Unit) 2 Bed: Ducted split heat pump; SEER2 17; HSPF2 9; (Interior Unit) (Exterior Unit) |
Duct Sealing | Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM. |
Mechanical Ventilation | ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery; All Units; (Product Ref) |
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 Based on kitchen volume & ≤ 1.0 sone. Both: Exhaust directly outdoors, ENERGY STAR certified (Product Rec). |
Thermostats | N/A |
DHW | HPWH In hallway (UEF ≥3.83) (1Bed Units) (2 Bed Units) |
Hot Water Piping | Hot water pipes insulated to R-3. |
Water Fixtures | Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM) |
Appliances | ENERGY STAR Certified All Electric Appliances (Refrigerator) (Dishwasher) (Washer/Dryer) |
Lighting | 100% high-efficacy (LED) |
Solar Ready | N/A |
Electric Vehicle Ready | Provide powered 208/240 V EV receptacle(s) for not less than 20% of parking spaces, each served by a dedicated ≥40 A circuit labeled “EV Charging.” |
Paperwork & Modeling | Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation. |
Testing & Verification | Blower Door Test, Duct Test Total, Mechanical Ventilation Testing, Room Balancing, Predrywall & Final Inspection. |
Recommended Design - Common Areas
Item | Detailed Specifications |
|---|---|
Roof | R-30 roof deck continuous insulation + R-13 spray foam in cavity. |
Floor Over Unconditioned Space | R-30 cavity spray foam + R-20 continuous insulation. |
Exterior Wood Framed Wall (EXT-W6-FCC & EXT-W6-FCC1) | R-21 batt in cavity + R-4 continuous insulation (U-0.051) |
Exterior Mass Wall (EXT-C8-INS-BR) | R-8.4 continuous insulation (U-0.090) |
Exterior Mass Wall (EXT-C8-INS-FCP) | R-8.4 continuous insulation (U-0.090) |
Exterior Mass Wall (EXT-C8-INS-EL) | R-8.7 continuous insulation (U-0.090) |
Exterior Mass Wall (EXT-CONC-INS) | R-8.7 continuous insulation (U-0.090) |
Exterior Metal Framed Wall (EXT-M6-BR) | R-21 batt in cavity + R-8.4 continuous insulation (U-0.055) |
Exterior Metal Framed Wall (EXT-M6-MP) | R-21 batt in cavity + R-8.4 continuous insulation (U-0.055) |
Slab Insulation | R-10 Perimeter Insulation (2 ft depth) |
Fixed Windows | U-0.34 / SHGC 0.40 |
Operable Windows | U-0.43 / SHGC 0.40 |
Glazed Entrance Door | U-0.60 / SHGC 0.40 |
Opaque Door | U-0.37 |
Space Conditioning | Ducted split heat pump; SEER2 15.2; HSPF2 7.8; |
Air Handler & Duct Location | 100% Inside Conditioned Space |
Duct Sealing | Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM. |
Mechanical Exhaust for Common Spaces | Measured exhaust rates are ≥ ASHRAE 62.1-2010 rates. |
Mechanical Exhaust for Shared Garages | Where an exhaust system is installed in a shared garage, it is equipped with controls that sense CO and NO2; Measured exhaust rates are ≥ ASHRAE 62.1-2010 rates. |
Thermostats | Programmable |
DHW | Electric Resistance or Tankless Water Heater UEF ≥0.93 |
Water Fixtures | WaterSense Certified Fixtures |
Appliances | ENERGY STAR Certified All Electric Appliances |
Lighting | 100% LED Lighting |
Solar Ready | Exempt - solar radiation available to the building is not suitable for a solar-ready zone (click to see exemption reasoning). |
Electric Vehicle Ready | EV Charging Compliance: Provide EV Ready spaces for not less than 20% of the total parking spaces. Compliance may be achieved through any combination of the following options: Option 1: Standard Dedicated Level 2 Provide EV Ready infrastructure for at least 20% of parking spaces, where each space is served by its own dedicated 208/240V, 40-amp branch circuit. Option 2: DC Fast Charger Exception Exempt the garage from the 20% wiring requirement entirely by installing and activating a minimum of four (4) DC Fast Chargers, each rated at 150 kW or higher. Option 3: Level 1 Substitution Meet the EV Ready target by substituting standard Level 2 (208/240V) spaces with Level 1 (120V, 20-amp) spaces at a 3-to-1 ratio. |
Net Cost Summary
Path | Total Cost $/sf | Total Incentives $/sf | Net $/sf |
|---|---|---|---|
DESIGNED | $41.25 | $0.00 | $41.25 |
ENVELOPE | $50.95 | $1.86 | $49.09 |
EQUIPMENT | $43.55 | $2.06 | $41.49 |
Envelope
Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf |
|---|---|---|---|---|---|
Exterior Walls | DESIGNED | 2×6 R-21 batt + R-4 continuous insulation. | $1.50 | $0.00 | $1.50 |
ENVELOPE | 2×6 R-34 spray foam + R-10 continuous insulation. | $4.00 | $0.00 | $4.00 | |
EQUIPMENT | 2×6 R-21 batt + R-4 continuous insulation. | $1.50 | $0.00 | $1.50 | |
Floor Over Unconditioned Space | DESIGNED | R-30 spray foam + R-22.2 batt insulation. | $1.20 | $0.00 | $1.20 |
ENVELOPE | R-30 cavity spray foam + R-20 continuous insulation. | $1.85 | $0.00 | $1.85 | |
EQUIPMENT | R-30 cavity spray foam + R-20 continuous insulation. | $1.85 | $0.00 | $1.85 | |
Rim Joists | DESIGNED | 2×6 R-21 batt + R-4 continuous insulation. | $0.15 | $0.00 | $0.15 |
ENVELOPE | 2×6 R-34 spray foam + R-10 continuous insulation. | $0.40 | $0.00 | $0.40 | |
EQUIPMENT | 2×6 R-21 batt + R-4 continuous insulation. | $0.15 | $0.00 | $0.15 | |
Roof | DESIGNED | R-30 roof deck continuous insulation + R-13 spray foam in cavity. | $1.80 | $0.00 | $1.80 |
ENVELOPE | R-30 roof deck continuous insulation + R-13 spray foam in cavity. | $1.80 | $0.00 | $1.80 | |
EQUIPMENT | R-30 roof deck continuous insulation + R-13 spray foam in cavity. | $1.80 | $0.00 | $1.80 | |
Windows | DESIGNED | U-0.30 / SHGC 0.30-0.40 | $7.00 | $0.00 | $7.00 |
ENVELOPE | U-0.18 / SHGC 0.25+ | $13.00 | $0.00 | $13.00 | |
EQUIPMENT | U-0.30 / SHGC 0.30-0.40 | $7.00 | $0.00 | $7.00 | |
Doors | DESIGNED | Glazed: U-0.30 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75); | $0.50 | $0.00 | $0.50 |
ENVELOPE | Glazed: U-0.18 / SHGC 0.25+; Opaque: U-0.21 (R-4.75); | $0.80 | $0.00 | $0.80 | |
EQUIPMENT | Glazed: U-0.30 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75); | $0.50 | $0.00 | $0.50 | |
Air Sealing | DESIGNED | Units: ≤3 ACH50; | $0.40 | $0.00 | $0.40 |
ENVELOPE | Units: ≤3 ACH50; | $0.40 | $0.00 | $0.40 | |
EQUIPMENT | Units: ≤3 ACH50; | $0.40 | $0.00 | $0.40 |
Mechanical
Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf |
|---|---|---|---|---|---|
Space Conditioning | DESIGNED | 1 Bed: Ducted split heat pump; SEER2 17.5; HSPF2 9; 2 Bed: Ducted split heat pump; SEER2 17; HSPF2 9; | $14.60 | $0.00 | $14.60 |
ENVELOPE | 1 Bed: Ducted split heat pump; SEER2 17.5; HSPF2 9; 2 Bed: Ducted split heat pump; SEER2 17; HSPF2 9; | $14.60 | $0.00 | $14.60 | |
EQUIPMENT | 1 Bed: Ducted split heat pump; SEER2 17.5; HSPF2 9; 2 Bed: Ducted split heat pump; SEER2 17; HSPF2 9; | $14.60 | $0.00 | $14.60 | |
Duct Sealing | DESIGNED | Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM. | $0.25 | $0.00 | $0.25 |
ENVELOPE | Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM. | $0.25 | $0.00 | $0.25 | |
EQUIPMENT | Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM. | $0.25 | $0.00 | $0.25 | |
Mechanical Ventilation | DESIGNED | ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery; All Units; | $3.00 | $0.00 | $3.00 |
ENVELOPE | ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery; All Units; | $3.00 | $0.00 | $3.00 | |
EQUIPMENT | ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery; All Units; | $3.00 | $0.00 | $3.00 | |
Local Mechanical Exhaust | DESIGNED | 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 Based on kitchen volume & ≤ 1.0 sone. Both: Exhaust directly outdoors, ENERGY STAR certified (Product Ref). | $1.50 | $0.00 | $1.50 |
ENVELOPE | 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 Based on kitchen volume & ≤ 1.0 sone. Both: Exhaust directly outdoors, ENERGY STAR certified. | $1.50 | $0.00 | $1.50 | |
EQUIPMENT | 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 Based on kitchen volume & ≤ 1.0 sone. Both: Exhaust directly outdoors, ENERGY STAR certified. | $1.50 | $0.00 | $1.50 | |
Thermostats | DESIGNED | N/A | $0.00 | $0.00 | $0.00 |
ENVELOPE | N/A | $0.00 | $0.00 | $0.00 | |
EQUIPMENT | N/A | $0.00 | $0.00 | $0.00 |
Plumbing & Appliances
Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf |
|---|---|---|---|---|---|
DHW | DESIGNED | Electric tank heater In hallway (UEF ≥0.94) (Product Ref) | $1.20 | $0.00 | $1.20 |
ENVELOPE | Electric tank heater In hallway (UEF ≥0.94) (Product Ref) | $1.20 | $0.00 | $1.20 | |
EQUIPMENT | HPWH In hallway (UEF ≥3.83) (Product Rec) | $2.85 | $0.20 | $2.65 | |
Hot Water Piping | DESIGNED | Hot water pipes insulated to R-3. | $0.15 | $0.00 | $0.15 |
ENVELOPE | Hot water pipes insulated to R-3. | $0.15 | $0.00 | $0.15 | |
EQUIPMENT | Hot water pipes insulated to R-3. | $0.15 | $0.00 | $0.15 | |
Water Fixtures | DESIGNED | Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM) | $0.50 | $0.00 | $0.50 |
ENVELOPE | Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM) | $0.50 | $0.00 | $0.50 | |
EQUIPMENT | Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM) | $0.50 | $0.00 | $0.50 | |
Appliances | DESIGNED | ENERGY STAR Certified All Electric Appliances | $2.85 | $0.00 | $2.85 |
ENVELOPE | ENERGY STAR Certified All Electric Appliances | $2.85 | $0.00 | $2.85 | |
EQUIPMENT | ENERGY STAR Certified All Electric Appliances | $2.85 | $0.00 | $2.85 |
Electrical
Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf |
|---|---|---|---|---|---|
Lighting | DESIGNED | 100% high-efficacy (LED) | $3.50 | $0.00 | $3.50 |
ENVELOPE | 100% high-efficacy (LED) | $3.50 | $0.00 | $3.50 | |
EQUIPMENT | 100% high-efficacy (LED) | $3.50 | $0.00 | $3.50 | |
Solar Ready | DESIGNED | N/A | $0.05 | $0.00 | $0.05 |
ENVELOPE | N/A | $0.05 | $0.00 | $0.05 | |
EQUIPMENT | N/A | $0.05 | $0.00 | $0.05 | |
EV Ready | DESIGNED | Provide powered 208/240 V EV receptacle(s) for not less than 20% of parking spaces, each served by a dedicated ≥40 A circuit labeled “EV Charging.” | $0.60 | $0.00 | $0.60 |
ENVELOPE | Provide powered 208/240 V EV receptacle(s) for not less than 20% of parking spaces, each served by a dedicated ≥40 A circuit labeled “EV Charging.” | $0.60 | $0.00 | $0.60 | |
EQUIPMENT | Provide powered 208/240 V EV receptacle(s) for not less than 20% of parking spaces, each served by a dedicated ≥40 A circuit labeled “EV Charging.” | $0.60 | $0.00 | $0.60 |
Soft Costs
Item | Path | Detailed Specifications | Cost $/sf | Incentive $/sf | Net $/sf |
|---|---|---|---|---|---|
Paperwork & Modeling | DESIGNED | Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation. | $0.50 | $0.00 | $0.50 |
ENVELOPE | Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation. | $0.50 | $1.86 | -$1.36 | |
EQUIPMENT | Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation. | $0.50 | $1.86 | -$1.36 | |
Testing & Verification | DESIGNED | Blower Door Test, Duct Test Total, Mechanical Ventilation Testing, Room Balancing, Predrywall & Final Inspection. | $0.00 | $0.00 | $0.00 |
ENVELOPE | Blower Door Test, Duct Test Total, Mechanical Ventilation Testing, Room Balancing, Predrywall & Final Inspection. | $0.00 | $0.00 | $0.00 | |
EQUIPMENT | Blower Door Test, Duct Test Total, Mechanical Ventilation Testing, Room Balancing, Predrywall & Final Inspection. | $0.00 | $0.00 | $0.00 |