Alone House


Airtightness (measured):

0.62 ACH50

Actual Energy Use Intensity (EUI):

1.4 kBtu/sf/yr

Surface Area to Volume:

0.21 sf/cf

Heat Loss Form Factor:


Home Energy Rating Score (HERS Index):


Rooftop solar PV:

3.78 kW (size); 4,373 kWh (est. annual solar production)

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 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