PROJECT.

Iowa City Nest

An all-electric, low-carbon Passive House


A simple, contemporary home, shaped by site and climate.

Problem


The owners wanted a super-efficient, durable, and inviting home on an infill site in Iowa City. With a tight lot in a newly-designated floodplain, and existing trees that the owners hoped to preserve, the home needed to seamlessly address numerous site and passive design constraints.

The key challenge, then, was to balance stringent Passive House performance requirements, the project budget, and compatibility with the surrounding fabric in a way that would create a warm, contemporary home.

Solution


Form follows context

The home is carefully sited to preserve existing trees and raise its floor above flood elevation with minimum site disturbance. It presents a low profile to the street to align in scale with its neighbors. A second story is tucked to the rear. The tandem garage takes advantage of rear alley access while minimizing its visual impact.

Opportunities in the details

Passive House details are critical for achieving super-efficient, air-tight construction. Here, we used those same details as opportunities for architectural expression. For example, where the home's thick insulation blanket peels away from the unconditioned garage -- a detail reinforced by a change in material.

Materials matter

Materials throughout the home were carefully selected in order to (1) reduce embodied carbon, (2) promote excellent indoor air quality, and (3) minimize ongoing maintenance. Key choices include the use of cellulose insulation in walls and roof, engineered wood siding, metal roofing, and low-emitting wood floors.

The Impact


PHIUS+ 2018 CORE Certified
Building envelope is a net carbon sink