The Center for Timber Innovation in the Built Environment at the University of Washington advances the understanding and adoption of mass timber as a sustainable, carbon-smart building material. Through interdisciplinary research, hands-on learning, and community partnerships, CTIBE drives innovation that supports both resilient communities and the natural systems that sustain them.
With Washington’s forests at a crossroads, responsibly managed second- and third-growth softwoods can provide affordable, climate-smart solutions for our state’s growing housing and infrastructure needs.
The Housing Futures Center (HFC) at the University of Washington advances solutions to Washington’s most pressing housing challenges through research, education, and community partnerships. HFC builds capacity and supports informed decision-making to ensure that every Washingtonian has access to affordable and stable housing.
Housing in Washington is increasingly out of reach for many families. Over the next two decades, the state will need more than 1.1 million new housing units, two-thirds of which must be affordable to households earning less than 80% of the area median income. HFC works to meet this need by connecting knowledge, policy, and practice across disciplines and communities.
Dehnavi AN, Manesh MT, Zomorodian Z, Abdolmaleki A, Hoonejani MR. INVESTIGATION OF A SILICA GEL-BASED EVAPORATIVE COOLING SHADING SYSTEM: NUMERICAL AND EXPERIMENTAL APPROACHES. Journal of Green Building. 2026 Jan;21(1):273–289. doi:10.3992/jgb.21.1.273
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Abstract
Passive evaporative cooling systems offer a low-cost, energy-efficient solution suited to hot and dry climates. This study integrates evaporative cooling within a shading system, creating an innovative approach to control daylight while enhancing thermal comfort. Silica gels are inserted into the louvers and placed in a water chamber, turning the louvers into wet evaporating plates. This evaporative shading system (ESS) is implemented on the inside-facing window opening, resulting in an integrated system for evaporative cooling and daylight control. A numerical model simulates variations in indoor air temperature and humidity caused by the system, which is further validated through experimental testing. Numerical modeling indicates that after 100 minutes at a height of 70 cm, the shading system successfully reduces the temperature by a range of 3.5 K while concurrently increasing relative humidity by approximately 3.5%. Subsequent experimental tests support these findings, demonstrating that the ESS reduces temperature by about 5 K and increases relative humidity by a range of 2 to 3.5%. This ESS demonstrates potential for thermal comfort enhancement and daylight optimization.
The Population Health Initiative has awarded eight early-stage pilot grants in November 2025. The project, “Embodied Nature Engagement: Developing the Interaction Pattern Preference Inventory (IPPI) for Nature Prescriptions in Primary Care” includes Sebastian Tong (Department of Family Medicine), Peter Kahn (Department of Psychology & School of Environmental and Forest Sciences), Ashley Park (Department of Family Medicine), and Hongfei Li (College of Built Environments). Hongfei Li is a lecturer and interdisciplinary PhD student in the Landscape Architecture department. Congratulations to Hongfei…
Ashour, L., & Shen, Q. (2025). An outlook on ride-sourcing price changes: Implications for future transit agency-TNC partnerships. Transport Policy, 173, Article 103790. https://doi.org/10.1016/j.tranpol.2025.103790
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Abstract
Ride-sourcing trip prices charged by transportation network companies (TNCs) have increased significantly compared to before the pandemic, causing concerns about the effectiveness of existing and planned transit agency-TNC partnerships. This paper explores three scenarios of future TNC price changes: (1) price trend extension using forecasting models, (2) price increase in response to local policy changes, and (3) TNC/taxi price convergence due to increased competition. We then investigate the impact of TNC price change on the prospect of transit agency-TNC partnerships, using a case study in the Seattle region. For the first scenario, we employ two time-series models, namely ARIMA and PROPHET, to forecast price changes within the next three years (Oct 2022–Oct 2025) using publicly available Chicago TNC trip data. The results show that TNC's daily average price would reach $3.23 per mile, increasing by 40 % from 2019 average rates. For the second scenario, we track significant policies that directly impacted TNC prices in Seattle and incorporate reported price increases. The resulting estimations indicate that TNC prices would increase by an extra 25 % in response to changes in the minimum wage law. For the third scenario, we use publicly available taxi trip data of the city of Chicago and forecast future taxi prices by estimating time-series models comparable to those for TNC prices. The analysis suggests that due to increased competition, TNC and taxi prices are converging and that the average TNC fare per mile could add another 50 % to the forecasted price if TNC and taxi prices become similar in the upcoming three years. These price changes are shown to have a considerable negative impact on the expected cost-effectiveness of transit agency-TNC partnerships. Although such partnerships could still provide many benefits, transportation planners and policymakers should carefully examine the implications of TNC price increases resulting from changing market and policy environments.
Ashour, L., & Shen, Q. (2025). Incorporating equity into the cost-effectiveness evaluation of new mobility: A comparative analysis. Transportation Research. Part D, Transport and Environment, 147, Article 104959. https://doi.org/10.1016/j.trd.2025.104959
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Abstract
Public transportation in suburban areas faces challenges in providing efficient mobility. Transit Incorporating Mobility on Demand (TIMOD) services have emerged as a potential solution, yet equity considerations remain underexplored. This study incorporates equity into the cost-effectiveness evaluation of TIMOD services, analyzing two suburban areas in the Seattle metropolitan region where a TIMOD service is implemented. Using distributional cost-effectiveness analysis (DCEA), we assess the comparative costs of TIMOD, fixed-route transit, and drive-alone across different income groups and built environments. The study shows that although TIMOD services offer equity benefits for lower-income travelers, they are more equitable in high-density, low-income suburbs. In contrast, their cost-effectiveness is more limited in affluent, low-density areas. These insights highlight the importance of context-specific planning for TIMOD interventions and employ tools such as DCEA for transit agencies to prioritize the deployment of such services in areas where they can maximize social welfare and reduce transportation inequities.
Cai, M., Ashour, L. A., Shen, Q., & Chen, C. (2025). Incorporating mobility-on-demand into public transit in suburban areas: A comparative cost-effectiveness evaluation. Transportation Research. Part D, Transport and Environment, 144, Article 104775. https://doi.org/10.1016/j.trd.2025.104775
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Abstract
Transit Incorporating Mobility-on-Demand (TIMOD) represents the public–private partnerships in which transit agencies incorporate MOD services to supplement fixed-route transit. This study evaluates the cost-effectiveness of TIMOD compared to buses, driving, and ride-hailing in suburban settings. For each alternative, it estimates the marginal costs for travelers, service providers, and transportation externalities, which constitute the marginal social cost. In the study cases, TIMOD is the least cost-effective option, with marginal social cost approximately 20% higher than TNCs and over three times higher than driving. For travelers, TIMOD costs more than driving but less than buses and ride-hailing when considering time value and fare. The cost of TIMOD declines as population density increases. Suburbs with less bus services and higher income residents benefit more from TIMOD, realizing greater reductions in time costs compared to buses. Transit agencies should explore alternative ways to improve mobility for disadvantaged suburban residents by offsetting driving costs and subsidizing TNCs fares.
Keywords
Transit Incorporating Mobility-On-Demand (TIMOD); Public transit; Transportation simulation; Suburban areas; Marginal social cost of travel
My research interests include housing policy, affordable housing, smart cities, housing markets, real estate markets, appraisals, development, sustainability and investments. Other areas that are of interest to me include facilities management, urban and city planning, and real estate economics.
Liu, Y., & Abbasabadi, N. (2025). Enhancing urban building energy models with Vision Transformers: A Case study in material classification from Google street view. Energy and Buildings, 333, Article 115457. https://doi.org/10.1016/j.enbuild.2025.115457.
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Abstract
The growing urbanization and increased urban energy consumption highlight the need for energy use and greenhouse gas emissions reduction strategies. Urban Building Energy Modeling (UBEM) emerged as a valuable tool for managing and optimizing energy consumption at the neighborhood and city scales to support carbon reduction goals. However, the accuracy of the UBEM is often limited by the lack of large-scale building façade material dataset. This study introduces a new approach to enhance UBEM by integrating an automatic deep learning material classification pipeline. The pipeline leverages multiple views of Google Street View Images (SVIs) to extract building façade material information, utilizing two Swin Vision Transformer (ViT) models to capture both global and local features from the SVIs. The pipeline achieved a main material classification accuracy reached 97.08%, and the sub-category accuracy reached 91.56% in a multi-class classification task. As the first study to apply a deep learning model for material classification to enhance the UBEM framework, this work was tested on the University of Washington campus, which features diverse facade materials. The model demonstrated its effectiveness by achieving an overall accuracy increase of 11.4% in year-round total operational energy simulations. The scalability of this material classification pipeline enables a more accurate and cost-effective application of UBEM at broader urban scales.
My interest lies in urban-scale building energy modeling and carbon accounting for climate mitigation. Specifically, I am focused on how digital documentation of the built environment can automate and enhance the accuracy of current accounting methods. Moreover, I am intrigued by how these advancements enable the broader application of bottom-up accounting approaches, informing early-stage design and influencing energy policy decisions.