Project Overview

Freeland Residence

High-Performance, Zero Energy Ready SIP Home in Washington

The Freeland Residence is a high-performance custom single-family home located in Washington, designed to deliver exceptional energy efficiency, indoor comfort, and long-term durability in a marine Pacific Northwest climate. From the outset, the project prioritized building envelope performance as the foundation for reduced energy demand and healthier indoor living.

Structural Insulated Panels (SIPs) were used as the primary building envelope system, enabling airtight construction, continuous insulation, and a simplified path to meeting rigorous energy and indoor air quality standards.

Design and Sustainability

Homes in coastal and marine climates must carefully manage moisture, air movement, and thermal performance. The Freeland Residence was designed with an envelope-first approach that reduces heat loss, limits air infiltration, and supports stable interior conditions throughout the year.

SIP construction plays a central role in this strategy by delivering an integrated system that combines structure, insulation, and air sealing. This approach minimizes thermal bridging and allows mechanical systems to be downsized for efficiency without compromising comfort.

Why SIPs?

Structural Insulated Panels (SIPs) were selected to help achieve the project’s ambitious performance and certification goals. SIPs provide superior airtightness and insulation continuity compared to conventional framing, making them well suited for homes targeting low HERS scores and advanced energy programs.

For the Freeland Residence, SIP construction simplified detailing, improved quality control, and supported a clear path to Zero Energy Ready performance.

Benefits of SIPs

The use of SIPs delivered several key advantages for this project:

• Energy Efficiency:
  Continuous insulation and airtight construction dramatically reduce heating and cooling loads.

• Interior Comfort:
  SIPs support even temperatures, reduced drafts, and quieter interior spaces.

• Mechanical Optimization:
  Lower loads allowed HVAC systems to be right-sized for efficiency and longevity.

• Construction Quality:
  Factory-built panels improve precision and reduce onsite variability.

Performance & Sustainability Features

• Certifications and Programs:

  • HERS Score: 40

  • ENERGY STAR® Certified Home

  • EPA Indoor airPLUS Qualified

  • DOE Zero Energy Ready Home Program Certified

• Airtightness:

  • Blower door test result: 0.69 ACH50, confirming exceptional envelope performance

• Heating, cooling, and hot water:

  • Ductless mini-split heat pump system with three indoor heads serving the master bedroom, flex room, and kitchen

  • Electric heat pump water heater meeting Tier I NEEA Advanced Water Heating Specification

• High-performance windows:

  • Triple-pane windows with an average U-value of 0.16

• Insulation and assemblies:

  • Interior sound walls with R-11 and R-19 insulation (3.5" and 5.5")

• Efficient lighting and appliances:

  • All ENERGY STAR® appliances

  • LED lighting throughout the home

• Healthy materials:

  • Low-VOC interior paints supporting improved indoor air quality

• Site considerations:

  • Owners completed all landscaping independently

Construction and Innovation

SIP construction enabled efficient enclosure of the home while maintaining thermal and air-barrier continuity across walls and roof assemblies. The panelized system supported faster dry-in, reduced coordination challenges, and improved consistency—key advantages for achieving advanced performance targets.

By reducing envelope complexity, the project team was able to focus on delivering measurable performance outcomes rather than compensating for inefficiencies.

Challenges and Solutions

Achieving airtightness levels below 1.0 ACH50 requires careful detailing and coordination. SIPs addressed this challenge by providing a robust, continuous enclosure that minimizes air leakage and supports high indoor air quality standards without added construction complexity.

Key Features

• Custom single-family residence in Washington

• Structural Insulated Panel (SIP) wall and roof construction

• HERS 40, ENERGY STAR®, Indoor airPLUS, and Zero Energy Ready certified

• Exceptional airtightness (0.69 ACH50)

• High-performance mechanical systems and windows

• Designed for durability, comfort, and long-term efficiency