Page 59 - 2021 SDCA Project

Building System Specifications

Refer to below table for detail and level of achievement recommendations for each category.

Building System Prototype Value Reference System Description

Specification

Walls R-Value ≥ 20 IECC 2012 3 inch rigid XPS

Roof R-Value ≥ 30 IECC 2009 5.5 inches of closed-cell spray foam in truss cavity

Floor R-Value ≥ 19 IECC 2012 Fiberglass-batts underneath floor, if applicable

Windows U-Value ≤ 0.3 ENERGY STAR NFRC Certified Window

SHGC ≤ 0.25 ENERGY STAR NFRC Certified Window

Air Leakage ACH50 ≤ 3 IECC 2012 Achieve continuous air barrier by sealing all wall, ceiling, and floor
penetrations to the outside

Mechanical Constant CFM 20 ASHRAE 62.2 Energy Recovery Ventilator (ERV); ducts deliver fresh air
Ventilation

Space SEER ≥ 14.5 ENERGY STAR Ductless mini-split heat pump
Conditioning
HSPF ≥ 8.2 ENERGY STAR

Water Heater EF ≥ 0.90 ENERGY STAR Tankless; gas

Appliances ENERGY STAR ENERGY STAR certified, if applicable

Lighting ENERGY STAR LED; ENERGY STAR certified

Plumbing fixtures Gallons Per 0.5 WaterSense Low-flow bathroom sinks
Minute (GPM)

Gallons Per 1.5 WaterSense Low-flow kitchen sink/shower
Minute (GPM)

Gallons Per ≤ 1.28 WaterSense Dual-flush water closets
Flush (GPF)

Table 1. Optimized Building Performance Implementation Requirements Table
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