

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
Non Certified 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: Future & Sons (Travis Douglas & team)
Energy Rater / Verifier: DSB Energy (David Berg)
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