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Blue House Northern Liberties

ALONE  HOUSE

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.

PROJECT STATS

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

Awards

2021 AIA Pennsylvania: Honor Award

2020 AIA Philadelphia: General Built, Merit Design Award

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