CS30 Energy Code Feasibility Study in Middleborough, Massachusetts

Energy code feasibility study for a 272-unit 4-Story Multifamily Building (x4) | 4 residential stories with a separate clubhouse. in Massachusetts. Compares multiple design paths. Recommended: MA DOER Alternative Energy Credits ($81,600). View full study.

Study Type
Energy Code Feasibility Study
State
Massachusetts
Units
272
Building Type
4-Story Multifamily Building (x4) | 4 residential stories with a separate clubhouse.
Fuel Type
All-Electric
Recommended Path
MA DOER Alternative Energy Credits ($81,600)

Goal

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

Project

  • Middleborough, MA 02346
  • 272 Units | 343,000 sqft
  • 4-Story Multifamily Building (x4) | 4 residential stories with a separate clubhouse.
  • New Construction | Stretch Code | HERS ≤ 45 if Electric | HERS ≤ 42 if Mixed
  • Energy Star MFNC v1.1 Certification Required

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.

MINI (Recommended): This path is the recommended strategy as it offers the lowest upfront construction cost ($38.40/sf) and the lowest final Net Cost ($38.16/sf). By utilizing decentralized cold-climate mini-splits and heat pump water heaters, we achieve a high level of efficiency that allows us to retain a standard, cost-effective building envelope (double-pane windows, R-21 walls) while easily passing the code. Unlike the Geothermal option, this path does not rely on long term operational expenditures to make the math work. While it lacks the operational efficiency of geothermal, its superior upfront affordability still makes it the safest and most viable financial choice for the project's current timeline.

GEO (Strong Alternative): Utilizing a Central Geothermal system, this path delivers the highest operational efficiency. However, the project is guaranteed to miss the deadlines for the 30% Federal ITC, leaving the full capital cost unsubsidized. Consequently, the Net Cost sits at $48.57/sf, roughly $10/sf higher than the Mini-Split path. Given it would take 25 years to recoup this premium through operational savings alone, the steep upfront capital requirement makes this a strong alternative but not the recommended strategy.

WALL (Not Recommended): This path attempts to save money on HVAC by using through-wall "All-in-One" units, but ultimately fails financially due to energy code penalties. Because the units have lower efficiency (SEER2 15.74), the energy model forces drastic and expensive envelope upgrades (triple-pane windows, heavy insulation), just to pass compliance. These costs completely erase the mechanical savings, driving the net cost to $45.25/sf, roughly $10 more per square foot than the recommended paths.

MIXED (Not Recommended): This path introduces natural gas for water heating and cooking, but creates a "worst of both worlds" financial scenario. By including gas, the code target tightens to HERS 42, which triggers the same expensive envelope upgrades as the Wall path (triple-pane windows, heavy insulation). You essentially pay for dual utility infrastructure (gas + electric) plus a premium building envelope, resulting in a net cost of $45.06/sf with no operational or financial upside compared to the all-electric options.

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

Total Incentives: $81,600

  • MA DOER Alternative Energy Credits ($81,600): You receive this performance-based incentive for installing the specific "Cold Climate" mini-splits recommended in this report, which qualify as a clean heating technology. You claim it by hiring an aggregator to "mint" and sell credits based on your system's thermal output. Payments are typically distributed within 6 months of all HVAC units being fully operational; note that depending on final efficiency multipliers and market conditions, the actual revenue could be 2–3 times higher than this conservative estimate.

Recommended Design - Units

Item

Detailed Specifications

Wood-Framed Exterior Walls

2×6 R-21 batt + R-4 continuous insulation (U-0.043)

Concrete Block Exterior Walls

8” Concrete Block + R-21 continuous insulation (U-0.043)

Floor Over Unconditioned Space

N/A

Slab

R-10 Fully Insulated Slab & 24" Perimeter (Int or Ext)

Rim Joists

2×6 R-23 Spray Foam

Roof

R-30 roof deck continuous insulation + R-13 spray foam in cavity (U-0.022)

Windows

U-0.30 / SHGC 0.30-0.40 (Product Rec)

Air Sealing

Units: ≤0.30 per sqft shell (Air Sealing Guidance)

Space Conditioning

Ductless Split Air Source Heat Pump (Cold Climate) with Direct Air Distribution via Wall-Mounted Indoor Units. (SEER2 ≥19.3 / HSPF2 ≥10.0) (1 Bed) (2 Bed) (3 Bed)

Duct Sealing

Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM. (Duct Sealing Guidance)

Mechanical Ventilation

ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery; (Product Rec)

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

All heating and cooling systems serving a dwelling unit have thermostatic controls within the dwelling unit.

DHW

Heat Pump Water Heater In Common Area Hallway (UEF ≥3.83) (1Bed Units) (2 Bed Units) (3 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) (Kitchen-Product Rec) (Bathroom-Product Rec) (Shower-Product Rec)

Appliances

ENERGY STAR Certified All Electric Appliances (Refrigerator) (Dishwasher) (Washer/Dryer)

Lighting

100% high-efficacy (LED)

Paperwork & Modeling

Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation.

Testing & Verification

Blower Door Test, 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 insulation + R-20 continuous insulation.

Exterior Wood Framed Wall

R-21 batt in cavity + R-4 continuous insulation (U-0.051)

Exterior Mass Wall

R-8.7 continuous insulation (U-0.090)

Exterior Metal Framed Wall

R-21 batt in cavity + R-8.4 continuous insulation (U-0.055)

Slab Insulation

R-10 Fully Insulated Slab & 24" Perimeter (Int or Ext)

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

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.

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

GEO Total Incentives: $4,980,000

  • Operational Budget (Avoided Costs & Capitalized Savings) ($4,980,000): You receive this value through a combination of reduced electrical infrastructure needs (smaller transformers/service sizes), drastically lower maintenance costs, and the avoidance of expensive equipment replacements "down the road" (as geothermal loops last 50+ years compared to 15 years for air-source units). You "claim" this value immediately via reduced upfront infrastructure spending and cumulatively through lower annual OpEx, which directly increases the building's Net Operating Income (NOI) and asset value. This value is realized partially at construction (infrastructure savings) and continuously over the life of the building (see this report for more details).

WALL Total Incentives: $0.00

  • None applicable.

MINI Total Incentives: $81,600

  • MA DOER Alternative Energy Credits ($81,600): You receive this performance-based incentive for installing the specific "Cold Climate" mini-splits recommended in this report, which qualify as a clean heating technology. You claim it by hiring an aggregator to "mint" and sell credits based on your system's thermal output. Payments are typically distributed within 6 months of all HVAC units being fully operational; note that depending on final efficiency multipliers and market conditions, the actual revenue could be 2–3 times higher than this conservative estimate.

MIXED Total Incentives: $81,600

  • MA DOER Alternative Energy Credits ($81,600): You receive this performance-based incentive for installing the specific "Cold Climate" mini-splits recommended in this report, which qualify as a clean heating technology. You claim it by hiring an aggregator to "mint" and sell credits based on your system's thermal output. Payments are typically distributed within 6 months of all HVAC units being fully operational; note that depending on final efficiency multipliers and market conditions, the actual revenue could be 2–3 times higher than this conservative estimate.

Path Comparison - Net Cost Summary

Path

Total Cost $/sf

Total Incentives $/sf

Net $/sf

GEO

$48.57

$0.00

$48.57

WALL

$49.50

$0.00

$49.50

MINI

$38.40

$0.24

$38.16

MIXED

$49.55

$0.24

$49.31

Path Comparison - Envelope

Item

Path

Detailed Specifications

Cost $/sf

Incentive $/sf

Net $/sf

Wood-Framed Exterior Walls

GEO

2×6 Wood Frame R-21 batt + R-4 continuous insulation (U-0.043)

$1.50

$0.00

$1.50

WALL

2×6 R-36 spray foam + R-10 continuous insulation (U-0.027)

$4.00

$0.00

$4.00

MINI

2×6 R-21 batt + R-4 continuous insulation (U-0.043)

$1.50

$0.00

$1.50

MIXED

2×6 R-36 spray foam + R-10 continuous insulation (U-0.027)

$4.00

$0.00

$4.00

Concrete Block Exterior Walls

GEO

8” Concrete Block + R-21 continuous insulation (U-0.043)

$2.80

$0.00

$2.80

WALL

8” Concrete Block + R-35 continuous insulation (U-0.027)

$4.25

$0.00

$4.25

MINI

8” Concrete Block + R-21 continuous insulation (U-0.043)

$2.80

$0.00

$2.80

MIXED

8” Concrete Block + R-35 continuous insulation (U-0.027)

$4.25

$0.00

$4.25

Floor Over Unconditioned Space

GEO

N/A

$0.00

$0.00

$0.00

WALL

N/A

$0.00

$0.00

$0.00

MINI

N/A

$0.00

$0.00

$0.00

MIXED

N/A

$0.00

$0.00

$0.00

Slab

GEO

R-10 Fully Insulated Slab & 24" Perimeter (Int or Ext)

$2.25

$0.00

$2.25

WALL

R-20 Fully Insulated Slab & 24" Perimeter (Int or Ext)

$3.00

$0.00

$3.00

MINI

R-10 Fully Insulated Slab & 24" Perimeter (Int or Ext)

$2.25

$0.00

$2.25

MIXED

R-20 Fully Insulated Slab & 24" Perimeter (Int or Ext)

$3.00

$0.00

$3.00

Rim Joists

GEO

2×6 R-23 Spray Foam

$0.30

$0.00

$0.30

WALL

2×6 R-38 Spray Foam

$0.40

$0.00

$0.40

MINI

2×6 R-23 Spray Foam

$0.30

$0.00

$0.30

MIXED

2×6 R-38 Spray Foam

$0.30

$0.00

$0.30

Roof

GEO

R-30 roof deck continuous insulation + R-13 spray foam in cavity (U-0.022)

$1.80

$0.00

$1.80

WALL

R-30 roof deck continuous insulation + R-13 spray foam in cavity (U-0.022)

$1.80

$0.00

$1.80

MINI

R-30 roof deck continuous insulation + R-13 spray foam in cavity (U-0.022)

$1.80

$0.00

$1.80

MIXED

R-30 roof deck continuous insulation + R-13 spray foam in cavity (U-0.022)

$1.80

$0.00

$1.80

Windows

GEO

U-0.30 / SHGC 0.30-0.40

$7.00

$0.00

$7.00

WALL

U-0.20 / SHGC 0.30-0.40

$13.00

$0.00

$13.00

MINI

U-0.30 / SHGC 0.30-0.40

$7.00

$0.00

$7.00

MIXED

U-0.20 / SHGC 0.30-0.40

$13.00

$0.00

$13.00

Doors

GEO

Glazed: U-0.30 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75);

$0.50

$0.00

$0.50

WALL

Glazed: U-0.20 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75);

$0.80

$0.00

$0.80

MINI

Glazed: U-0.30 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75);

$0.50

$0.00

$0.50

MIXED

Glazed: U-0.20 / SHGC 0.30-0.40; Opaque: U-0.21 (R-4.75);

$0.80

$0.00

$0.80

Air Sealing

GEO

Units: ≤0.30 per sqft shell

$0.40

$0.00

$0.40

WALL

Units: ≤0.30 per sqft shell

$0.40

$0.00

$0.40

MINI

Units: ≤0.30 per sqft shell

$0.40

$0.00

$0.40

MIXED

Units: ≤0.30 per sqft shell

$0.40

$0.00

$0.40

Path Comparison - Mechanical

Item

Path

Detailed Specifications

Cost $/sf

Incentive $/sf

Net $/sf

Space Conditioning

GEO

Central Ground Source Heat Pump (Water-to-Water) with 4-Pipe Hydronic Distribution to In-Unit Ducted Fan Coils. (EER ≥17 / COP ≥4.5)

$18.00

$0.00

$18.00

WALL

Decentralized Through-Wall Air Source Heat Pump (All-In-One) with Ductless Direct Air Distribution via Wall-Mounted Console. (SEER2 ≥15.74 / HSPF2 ≥8.45)

$7.00

$0.00

$7.00

MINI

Ductless Split Air Source Heat Pump (Cold Climate) with Direct Air Distribution via Wall-Mounted Indoor Units. (SEER2 ≥19.3 / HSPF2 ≥10.0) (1 Bed) (2 Bed) (3 Bed)

$7.00

$0.24

$6.76

MIXED

Ductless Split Air Source Heat Pump (Cold Climate) with Direct Air Distribution via Wall-Mounted Indoor Units. (SEER2 ≥19.3 / HSPF2 ≥10.0) (1 Bed) (2 Bed) (3 Bed)

$7.00

$0.24

$6.76

Duct Sealing

GEO

Total Duct Leakage: The greater of ≤ 8 CFM25 per 100 sq. ft. of CFA or ≤ 80 CFM.

$0.25

$0.00

$0.25

WALL

N/A

$0.00

$0.00

$0.00

MINI

N/A

$0.00

$0.00

$0.00

MIXED

N/A

$0.00

$0.00

$0.00

Mechanical Ventilation

GEO

ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery;

$3.00

$0.00

$3.00

WALL

ERV: Integrated Through-Wall ERV: 15, 20, 25 CFM, 77-81% Sensible Recovery;

$3.00

$0.00

$3.00

MINI

ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery;

$3.00

$0.00

$3.00

MIXED

ERV: 53, 66, 85 CFM, ≤ 1.8 CFM per Watt, 77-83% recovery;

$3.00

$0.00

$3.00

Local Mechanical Exhaust

GEO

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

WALL

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

MINI

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

MIXED

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

GEO

All heating and cooling systems serving a dwelling unit have thermostatic controls within the dwelling unit.

$0.30

$0.00

$0.30

WALL

All heating and cooling systems serving a dwelling unit have thermostatic controls within the dwelling unit.

$0.30

$0.00

$0.30

MINI

All heating and cooling systems serving a dwelling unit have thermostatic controls within the dwelling unit.

$0.30

$0.00

$0.30

MIXED

All heating and cooling systems serving a dwelling unit have thermostatic controls within the dwelling unit.

$0.30

$0.00

$0.30

Path Comparison - Plumbing & Appliances

Item

Path

Detailed Specifications

Cost $/sf

Incentive $/sf

Net $/sf

DHW

GEO

Central Geothermal Water-to-Water Heat Pump (COP ≥3.0) with Temperature/Flow-Activated Demand Controlled Recirculation.

$1.75

$0.00

$1.75

WALL

Heat Pump Water Heater In Common Area Hallway (UEF ≥3.83)

$2.85

$0.00

$2.85

MINI

Heat Pump Water Heater In Common Area Hallway (UEF ≥3.83)

$2.85

$0.00

$2.85

MIXED

High-Efficiency Condensing Tankless Gas Water Heater with Integrated Recirculation Pump and Buffer Tank. (UEF ≥0.95 / Energy Star Certified)

$3.00

$0.00

$3.00

Hot Water Piping

GEO

Hot water pipes insulated to R-3.

$0.15

$0.00

$0.15

WALL

Hot water pipes insulated to R-3.

$0.15

$0.00

$0.15

MINI

Hot water pipes insulated to R-3.

$0.15

$0.00

$0.15

MIXED

Hot water pipes insulated to R-3.

$0.15

$0.00

$0.15

Water Fixtures

GEO

Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM)

$0.50

$0.00

$0.50

WALL

Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM)

$0.50

$0.00

$0.50

MINI

Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM)

$0.50

$0.00

$0.50

MIXED

Low flow fixtures (Lavatory: ≤1.5 GPM, Shower: ≤2.0 GPM)

$0.50

$0.00

$0.50

Appliances

GEO

ENERGY STAR Certified All Electric Appliances

$2.85

$0.00

$2.85

WALL

ENERGY STAR Certified All Electric Appliances

$2.85

$0.00

$2.85

MINI

ENERGY STAR Certified All Electric Appliances

$2.85

$0.00

$2.85

MIXED

ENERGY STAR Certified All Electric Appliances

$2.85

$0.00

$2.85

Path Comparison - Electrical

Item

Path

Detailed Specifications

Cost $/sf

Incentive $/sf

Net $/sf

Lighting

GEO

100% high-efficacy (LED)

$3.50

$0.00

$3.50

WALL

100% high-efficacy (LED)

$3.50

$0.00

$3.50

MINI

100% high-efficacy (LED)

$3.50

$0.00

$3.50

MIXED

100% high-efficacy (LED)

$3.50

$0.00

$3.50

Path Comparison - Soft Costs

Item

Path

Detailed Specifications

Cost $/sf

Incentive $/sf

Net $/sf

Paperwork & Modeling

GEO

Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation.

$0.04

$0.00

$0.04

WALL

Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation.

$0.04

$0.00

$0.04

MINI

Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation.

$0.04

$0.00

$0.04

MIXED

Energy model, 2021 IECC checklists, ENERGY STAR MFNC, and incentive documentation.

$0.04

$0.00

$0.04

Testing & Verification

GEO

Blower Door Test, Duct Test Total, Mechanical Ventilation Testing, Room Balancing, HVAC Grading, Predrywall & Final Inspection.

$0.17

$0.00

$0.17

WALL

Blower Door Test, Room Balancing, Predrywall & Final Inspection.

$0.16

$0.00

$0.16

MINI

Blower Door Test, Mechanical Ventilation Testing, Room Balancing, Predrywall & Final Inspection.

$0.16

$0.00

$0.16

MIXED

Blower Door Test, Mechanical Ventilation Testing, Room Balancing, Predrywall & Final Inspection.

$0.16

$0.00

$0.16