Inspire Apartments Living Building in Seattle, WA

Living Building Challenge Petal certification (Energy, Place, Beauty)

The Living Building Pilot Program is designed to encourage sustainable building practices from energy efficiency and renewable energy generation to water conservation and community engagement. As an incentive for accepting the Living Building Challenge, the project was allowed to construct an additional floor, hence the presence of 5 floors as opposed to the area’s usual limit of 4. The Building must be verified post-occupancy within two years following project completion by the International Living Futures Institute, on behalf of the Seattle Department of Construction and Inspections. In order to comply with the Living Building Pilot Program, the building must either fulfill the Living Building Challenge or achieve Petal Compliance (implement 3 of the 7 Living Building Challenge requirements, one of which must be the energy, water, or materials requirements). Seattle’s ordinance also requires the building use 25% less energy as outlined by Seattle Energy Code section C401.3, and use non-potable water where legally allowed. The Inspire project achieved the energy, place, and beauty petals. Achieving the energy petal was possible due energy efficient design and a solar array. An airtight thermal envelope and large south-facing triple-pane windows provide efficient heating through the use of passive solar gain. To ensure a healthy comfortable living space, two Zehnder 550 HRV units are installed on each floor of the building to exhaust interior air and bring in fresh outside air, while exchanging the heat between incoming and outgoing air to reduce heat loss through ventilation.

Properly ventilating the space while adhering to code and conserving energy required an innovative code pathway. The 2015 Seattle Mechanical Code Table 403.3.1.1 (page 39) stipulated that each dwelling unit receive 30 cfm of incoming air in the bedroom, exhaust 20 cfm of air through the bathroom, and exhaust an additional 25 cfm of air through the kitchen. In response, the project architect (Scot Carr of Public47 Architects) filed a Code Modification request with the Seattle Department of Construction and Inspections, which included a letter written by the engineer of record (Charles Gronek of WSP). The engineer’s letter asserts that the ventilation requirements prescribed by the 2015 SMC are excessive for the size of the dwelling units (288-560 sf), and would lead to overventilation and wasted energy. The engineer then suggested ventilating the dwelling units via a 30 cfm exhaust system in the bathroom, connected to the kitchen via a transfer mechanism. The engineer cited ASHRAE standard 62.1, which allows the transfer of class 2 air through a bathroom before being exhausted, and noted that kitchen exhaust air is considered class 2 air. The engineer also explicitly mentioned that ASHRAE Standard 62.1 serves as the foundation of many aspects of the Seattle Mechanical Code. Using this method, the mechanical engineer reported an additional improvement in energy efficiency of 0.9 EUI (i.e. kBTU/ft2/year, a measure of efficiency). The Seattle DCI accepted the code modification, though required the engineer of record to later confirm that the energy usage estimates established previously had not been increased by the alternative compliance path.

The primary motivation behind the Inspire project is to demonstrate that multi-family dwellings can be designed to adhere to the principles of sustainability without sacrificing commercial success. This aspiration coincides with community education and engagement, another key motive driving the project. The prospect of an extra floor (or two, if they comply with the living building challenge) is a compelling incentive for multistory dwellings in Seattle’s highly competitive housing market, as an extra floor provides a significant increase of marketable units. It also offers a competitive advantage to a development company that uses sustainable development practices, as there are a limited number of companies with the skills and knowledge to work on sustainable development projects.

Inspire was borne from the property owner’s desire to build upon their grandfather’s legacy of community engagement. Because the owner was familiar with the Living Building Pilot Program, they chose to redevelop the site with sustainability in mind, and prove that sustainable multi-family buildings could be developed in Seattle. Public47 Architects was brought on to design the building, which leverages excellent solar exposure available at the build site to provide passive solar heating to dwelling units via large, triple-glazed windows. The solar exposure coupled with the community outreach objectives helped direct the Petal Compliance process, leading to the fulfillment of the energy, place, and beauty petals. Inspire plans to focus heavily on educating their tenants in sustainable living, in part by sharing their operational goals and providing tenants with personal usage data via on-site monitoring. The project is expected to reach completion in Q3 of 2019.

The estimated financial benefit of the property is a development yield of 6.5%. The 12.5ft increase in building height as allowed by the City of Seattle for compliance with the Living Building Pilot Program for Petal Certification translates into an additional floor of dwelling units, which helps to recoup the costs associated with sustainable building. Further savings are achieved by the heavy usage of solar panels, which sharply reduce the cost of power by using renewable methods, and passive solar, capitalizing on large windows to decrease the need for artificial heating or cooling. The environmental and community impacts of the project should not be ignored, as this building serves as a proof-of-concept for others in the area, promoting the validity and feasibility of sustainable living in the community. While the FAR bonus incentive was not a primary motivation behind this project, it should be noted that the prospect of one, or possibly two, additional floors of marketable space may tempt conventional builders into adopting more sustainable practices.

Education about green building certifications, innovations, and building codes is needed throughout the community to create more demand for sustainable building. Seattleites have a general understanding of sustainability, in terms of solar panels, for instance, even if the Living Building Challenge is relatively unknown.  Both homeowners and renters generally are unaware of easy ways to reduce energy usage and inefficiencies throughout their homes, or that a sustainable, competitively-priced home can have no electric bill at all. This complicates the process of marketing high-performance homes, as potential owners or renters aren’t necessarily looking for net-zero energy or Passive House dwellings, especially when compared to characteristics such as location, living area, and noise insulation.

This lack of awareness, coupled with the cooling real estate market which is expected to reduce rental income  in Seattle in coming years, is forcing developers considering sustainable building to reassess their position and determine whether building green is financially viable.  The process of getting certified for the Living Building Challenge poses difficulties, but as this project has demonstrated, the outcome will be worth it financially to both the owners (additional units increase revenue) and to the renters (competitive pricing, no electric bills).

Successfully transitioning to new, more sustainable codes can also prove difficult for regulatory bodies and consumers. For instance, while the Inspire project had planned to include onsite greywater treatment, the recent adoption of the 2015 Seattle Plumbing Code required adhering to a new compliance path. The King County Department of Public Health (KCPH), still adjusting to the new standard, was unable to provide a compliance path for the project, and the greywater treatment plan eventually had to be dropped. The struggle to effectively coordinate with KCPH exemplifies the difficulties of navigating new codes and standards in a timely manner, even for experienced officials. Fortunately, a compliance path was later determined for the project, and key members of the project hope to collaborate further with KCPH, the International Living Future Institute and ReCode to develop an open-source guidebook for those hoping to create a compliant greywater treatment plan.

• 2015 Seattle Mechanical Code, Chapter 4 Ventilation
• 2018 Seattle Living Building Pilot Program