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Blue House Northern Liberties


Single Family Residential
New Construction
2,450 SF
Philadelphia, PA

This small citadel developed through the owner’s desire for a house-as-retreat. After observing a decade of rapid change in their Philadelphia neighborhood— gritty artist studios and open green lots infilled with mass residential development and large-scale construction— the owner’s sought a new home to fortify themselves from their changing environment.

As opposed to traditional rowhome construction where neighbors share a party wall, the building pulls away from its masonry neighbors to produce two buffer yards. This reduces noise infiltration from adjacent properties while offering a continuous belt of outdoor living space. In comparison to the nearly windowless street-facing walls, the house becomes permeable at the rear to maximize solar exposure. Double-stud exterior walls create fourteen inches of sound and thermal attenuation between public street and private interior.  An energy-model informed, integrated design approach led to a right-sized relationship between the building envelope and mechanical systems, laying the foundation for reduced energy use and a healthy indoor environment.


Passive House

Building Geometry

Surface Area to Volume: 0.21 sf/cf

Heat Loss Form Factor: 3.13

Building Metrics

Predicted Energy Use Intensity (pEUI): 4.39 kBtu/sf/yr

Actual Energy Use Intensity (EUI): 1.4 kBtu/sf/yr

Home Energy Rating Score (HERS Index): 14

Airtightness (measured): 0.62 ACH50

Building Envelope

Slab On Grade: R-22.5

Below / Above Grade Walls: R-28 / R-42

Roof: R-72

Windows: Average SHGC .61, average U-Value .21

Skylights: SHGC .49, U-Value .15

Building Systems

Power / Fuel Source(s): All electric

Renewable Energy: Rooftop solar PV (3.78 kW system size; 4,373 kWh est. annual solar production)

Heating & Cooling: Ductless mini-split heat pump

Ventilation: Energy recovery ventilator

Domestic Hot Water: Heat pump water heater

Appliances: Energy-Star

LED lighting

Low-embodied carbon building envelope

Project Team

Design-Builder: Future & Sons

Solar Provider: Solar States 

Photography: Sam Oberter


2021 AIA Pennsylvania: Honor Award

2020 AIA Philadelphia: General Built, Merit Design Award

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