“Desks to Dwellings: Tackling office-to-residential conversions”

Government bodies and municipalities across the U.S. are listening to developers and are seeking ways to facilitate the opportunities presented by these projects by offering incentive programs. These programs attempt to streamline the process and speed up the redevelopment of vacant office buildings.

While each city has its own program, Seattle specifically confronts cost alleviation and regulatory requirements. The Seattle City Council’s sales and use tax deferral on construction costs lowers overall project expenses as long as the developer dedicates 10% of units for affordable housing throughout 10 years. The city council also eliminated design reviews and development standards for office-to-residential conversions, reducing the time a project spends in the approval process, which can be several months. In addition to cost incentives, small expansions to existing structures are permissible to accommodate new residential use.

The city of Seattle hopes these legislative changes will result in 1,000-2,000 new homes in the next seven years, and office-to-residential conversions offer a less wasteful means of tackling the housing crisis.

In the last twenty years, 1.3 percent of the total commercial space in the Seattle area (which includes 14 office buildings) has been converted or is planned to be converted into housing, hotels, or life science labs. The 201 Queen Anne Ave. N project is among them, with construction starting within the next two months.

Before starting the project, Coughlin Porter Lundeen’s structural engineers dug through archival drawings and reports to gain a fundamental understanding of the existing building. Access to prolific drawing and report archives is crucial to providing an accurate assessment and determining feasibility of the adaptive reuse transformation.

The vacant four-story office’s revitalization into a 74-unit apartment building is possible due to the building’s relatively small floor plate and existing two-story parking garage tucked neatly into the sloped site. As office-to-residential conversions become more common in Seattle, it’s more likely that two- to six-story buildings will be rehabilitated due to their size, in contrast to New York City’s fleet of high rises. Zones in Seattle which allow conversion projects typically have buildings with fewer floors.

Conversion projects are often labeled as cost prohibitive without fully understanding cost saving opportunities. The design team can maintain as much as possible from the building’s existing structure while balancing necessary changes. This eliminates unnecessary demolition, reducing waste and embodied carbon from new building materials.

The 201 Queen Ave. N. architect, Board & Vellum, is preserving the façade but painting it from an outdated 1980s tan to a sleek onyx, alleviating significant project cost burden. Although most of the window system remains, a certain amount of the glazing will be replaced with operable windows to allow fresh air into apartment units. A small expansion consisting of a fifth-floor penthouse breaks up the façade with a warm touch of wood on top of the existing concrete structure.

Rather than removing any part of the outdated structural and seismic system, Coughlin Porter Lundeen is mitigating the existing reinforced concrete structure by incorporating two high-tech seismic upgrade methods. One acts like a shock absorber during an earthquake, while the other reinforces the existing concrete columns by wrapping them in thin but strong polymer material.

Seismic upgrades can be a considerable expense for conversion projects. Still, creative decisions such as rehabilitating the existing structure rather than replacing it with new systems can avoid excessive cost increases and schedule delays.

Due to the transformative nature of office-to-residential conversions, coordination with the city of Seattle is essential because these projects often involve negotiation. In some ways, our Coughlin Porter Lundeen team members act like an owner’s representative, navigating the negotiation process and helping the design team understand code requirements, while making a convincing case to the city for the proposed design during the project review process.

As these project types address larger public policy goals, the city is increasingly willing to provide flexibility for addressing Seattle’s unique Substantial Alteration requirements regarding structure, seismic, fire, life safety, accessibility and energy conservation.

Office-to-residential conversions push the boundaries of tackling big-picture issues like providing housing stock and addressing office vacancies. They maximize the inherent potential of existing buildings and eliminate the need to construct new ones.

These projects are becoming increasingly viable with innovative design solutions, Seattle’s strategic incentives, and proactive collaboration with city officials. As these adaptive reuse projects become more common, Seattle steps closer to a future where adaptability is key to sustainable urban living.