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Exterior Rendering


Single Family Residential
New Construction
1,800 SF
Philadelphia, PA

Tier House developed from the owners’ desire for a home that prioritized long term resiliency, comfort and reduced energy bills.  Using Passive House as a template to achieve their goals, the architectural team looked to complement the certification program’s clinical rigor by reducing design complexity: Tier House utilizes a stacked structural system without offsets or protrusions, one exterior building material and a single window type.  The resulting design uses color and pattern to break the house into two tiers- a heavy cap hovering above a light base- marrying visual sophistication with compositional restraint and sensible building science.


Targeting Phius CORE 2021 Prescriptive Certification

Building Geometry

Heat Loss Form Factor: 2.21

Window to Wall Ratio: 10.2

Building Metrics

Predicted Energy Use Intensity (pEUI): 2 kBtu/sf/yr (as designed, w/ Rooftop solar PV)
Predicted Embodied Carbon (modeled): 100 eCO2e

Airtightness (target): 0.04 CFM50/sf envelope area

Building Envelope

Slab on Grade: R-24
Exterior Walls: R-39
Roof: R-67

Windows: U-Value 0.14, SHGC 0.4 approx.

Building Systems

Power / Fuel Source(s): All electric
Renewable Energy: Rooftop solar PV (5.04 kW system size; 6,451 kWh est. annual solar production)
Heating & Cooling: Air-source heat pump
Ventilation: Energy Recovery Ventilator
Hot Water: Heat-pump water heater
Appliances: Energy-Star
LED lighting

Low-embodied carbon building envelope


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