HERS 258 Old Wilson Rd Northampton Energy Efficiency Plan
ENERGY EFFICIENCY PLAN
Project Address: 258 Old Wilson Rd, Northampton, MA
Conditioned Floor Area 3,559 ft2
Volume 45,265 ft3
Building Type Single family detached
Bedrooms 4
Assumptions for Preliminary Home Energy Rating
CET has completed a Preliminary Home Energy Rating based on the construction plans you have provided. Any
energy features not listed below are assumed to meet the prescriptive requirements of the IECC 2018.
Building Envelope Specifications Used in Analysis
Foundation Walls
Superior Wall Xi with R-21 fiberglass batts in cavities—Grade 1 (fully
lofted and fitted around all obstructions with no gaps, all cavities
completely filled with insulation and fully enclosed by rigid air barrier on
interior); ≥ 12” deep ½” crushed stone base under slab.
Lower Level Floor Slab R-20 sub-slab insulation;
Photo-document slab insulation prior to pouring concrete.
Rim & Band Joists 4” closed cell spray foam (R-24+) including onto top of foundation wall.
Exterior Walls 10” Cavity double 2x4 stud wall with dense-packed cellulose (R-35);
Sheathing joints, edges and penetrations taped/sealed.
Walls to Garage Same as exterior walls; Garage-side sheathing sealed to top of
foundation wall/slab and to wall top plate.
Windows & Glass Doors U-value = 0.28, SHGC = 0.28
Door to Garage R-5 / U-0.20, fully gasketed with sweep.
Vaulted Trussed Ceilings R-60 dense-pack cellulose in open-web roof trusses; sealed eave wind
baffles, full insulation contact with sheetrock ceiling.
Blower Door Test/Envelope Airtightness 0.6 ACH50 or lower, achieved with Aerobarrier system.
Energy Star, IAP, & ZERH Checklists Meet all Checklist Requirements as verified by a HERS rater at pre-
drywall and final inspection.
Plumbing & Mechanical Systems Specifications Used in Analysis
Heating & Cooling Equipment
Ducted air-source heat pumps, 9.5 HSPF, 16 SEER, ≥ MERV 8 filters;
Electric resistance supplemental heat: 4,000 watt allowance (2
bathroom wall heaters x 2,000 watts each).
Thermostats 7-day programmable
Water Heating Equipment 3.39 Energy Factor heat pump water heater
Domestic Hot Water Pipes <.5 gallons maximum capacity between water heater and any fixture.
Showerheads & Bathroom Lavatory Faucets WaterSense labeled
Heating/Cooling Duct Leakage
.04 CFM25 total leakage per sq ft conditioned floor area when tested
at 25 pascals pressure;
0 leakage to outdoors (100% within conditioned envelope).
Whole House Ventilation
High Efficiency Heat Recovery Ventilator, 76% ASRE and 32 watts at
73 CFM minimum continuous ventilation; return air duct directly from
house; Adjustable speed control.
Basis: Broan HRV160TE
ENERGY EFFICIENCY PLAN
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Lighting & Appliances Specifications Used in Analysis
Lighting 100% LED, CFL, or pin-based fluorescent
Refrigerator ENERGY STAR certified
Dishwasher ENERGY STAR certified
Clothes Washer & Dryer ENERGY STAR certified
Ceiling Fans (if present) ENERGY STAR certified
Preliminary Home Energy Rating Results
Based on the assumptions described above, we have calculated the following Preliminary Home Energy Rating results.
Preliminary HERS Index: 46
Note that Confirmed Home Energy Rating results may vary from the Preliminary Home Energy Rating results due to
changes in building plans, energy features installed in the home, RESNET standards, software changes, and other
factors.
Available 2018 IECC Stretch Code HERS Index Offsets Offset
Photovoltaic system 2.5 kw or greater 5 points
Renewable energy primary heating system, including Clean
Biomass Heating System, solar thermal array, cold climate air
source heat pump (COP of 1.75 at 5 degrees F), or ground
source heat pump
5 points
Solar thermal array for domestic hot water 2 points
Preliminary Rater: John Saveson
Date: Sept 22, 2021
Job #: 21-24784-2