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Blue House Northern Liberties


Single Family Residential
New Construction
2,450 SF
Philadelphia, PA: Northern Liberties

This small citadel developed through the owner’s desire for a house-as-retreat. For the better part of a decade, the occupants of this single-family house experienced rapid change in their Philadelphia neighborhood: gritty artist studios and open green lots were infilled with mass residential development and large-scale construction. The project fortifies the residents from the 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 eliminates 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 where maximum solar exposure occurs. Double-stud exterior walls create fourteen inches of sound attenuation between street and interior. Thicker assemblies and air-tight construction provide for smaller mechanical systems, minimal energy bills and indoor air quality that is otherwise rare in an urban setting.


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

Energy recovery ventilation

Domestic Hot Water: Heat pump water heater

Appliances: Energy-Star

LED lighting

Low-embodied carbon building envelope

Electric car charger ready

Project Team

Design-Builder: Travis Douglas & Team, Future & Sons

Energy Rater/Verifier: David Berg, DSB Energy

Structural Engineer: Larsen & Landis

Solar Provider: Solar States 

Photography: Sam Oberter


2021 AIA Pennsylvania: Honor Award

2020 AIA Philadelphia: General Built, Merit Design Award

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