High Performance ICF
Location: Bellevue, WA
Design Goals: The existing aging home on this Factoria neighborhood property in Bellevue was demolished to make way for a new, high-performance modern residence designed with efficiency, sustainability, and long-term livability in mind. The approximately 3,000-square-foot, two-story home features a high-performance building envelope, including insulated concrete forms (ICF) for both the foundation and exterior walls. These ICF walls extend continuously from foundation to roof, creating a tight, well-insulated assembly with minimal thermal transfer. The roof employs structural insulated panels (SIPS) supported by exposed steel beams, allowing for large open spans while maintaining energy efficiency. Together, these systems reduce energy demand for heating and cooling, providing a highly comfortable and sustainable living environment. Mechanical systems were carefully engineered to match the home’s low-energy requirements, providing efficient ventilation for the tight envelope. The roof includes a photovoltaic array to generate solar energy for household use and to support charging of the homeowner’s electric vehicle. Interior spaces were thoughtfully laid out to reflect the homeowners’ lifestyle and long-term needs. The main floor features an open plan connecting the kitchen, living, and dining areas, accentuated by vaulted ceilings, exposed steel beams, and large windows. Supporting spaces—including a primary suite, powder room, mudroom, and auxiliary areas—enable accessible, aging-in-place living. The lower floor includes a recreation area, two bedrooms, an office, a bathroom, and a workshop, creating a versatile and functional space for both work and leisure.
Style: Contemporary
Design Challenges + Site Constraints: This in city property presented a unique combination of technical, topographical, and siting challenges. The client’s desire to use insulated concrete forms (ICF) continuously from foundation to roof required careful planning and detailing to ensure structural integrity, energy performance, and constructability. The sloping topography naturally lent itself to a single-story main floor over a daylight basement, but also required thoughtful massing to work with the grade while minimizing site disturbance. As an infill lot, buildable locations were limited, which required strategic siting of the house to maximize solar access for photovoltaic panels while respecting setbacks, territorial views, and privacy. In addition, the driveway and main entry had to be carefully designed to minimize steep slopes, providing safe, accessible access for residents and supporting aging-in-place goals. Balancing these constraints required an integrated approach to architecture, site planning, and engineering to create a home that is highly efficient, accessible, and fully responsive to the site conditions.
Team:
+ Architecture: H2D Architecture + Design
+ Interior Design: H2D Architecture + Design
+ Built by: Carlisle Classic Homes