Commissioners covered bird-safe design standards, eco roofs and a cost analysis of new and/or updated regulations for future development
On January 24, 2017, the Planning and Sustainability Commission (PSC) held a work session for the Central City 2035 Plan. Commissioners discussed bird-safe glazing, ecoroof regulations and the cumulative cost of new regulations on future development.
Bird safe glazing
Research shows that up to 1 billion birds die every year in the United States from flying into windows. This is mainly due to the reflection of street trees and other vegetation onto glass, which creates a habitat “mirage.” Most birds are killed on impact when they collide with windows at full speed.
In Portland, the surface area of buildings that poses the highest risk of strikes is the first 60 feet from the ground. Windows (or glazing) adjacent to an ecoroof and/or the river and areas near groups of trees also create high risk areas.
Seeking to reduce the number of bird fatalities, City Council directed Bureau of Planning and Sustainability staff to establish bird-safe design standards in 2013. Based on public testimony, project staff worked with the bureaus of Development Services and Environmental Services to develop and modify new regulations to reduce the number of bird strikes.
- Applying the standard across the entire Central City rather than only in areas with high tree canopy.
- Applying a 30-percent glazing threshold for triggering the standard. This will capture predominately residential and commercial buildings with more glazed surface while exempting most traditional industrial development.
- Creating an administrative rule to easily add to the list of available glazing options in the future.
- Requiring special glazing on ground floor windows to help meet City goals for active ground floor use.
PSC Action: Supported the proposed staff amendments.
Approximately 24 acres of ecoroofs have been installed on top of Portland buildings since the 1990s. Ecoroofs enhance the quality of urban life by providing multiple environmental, economic and human health benefits, including:
- Reducing the costs of heating and cooling in a building throughout the year by insulating the building’s roof.
- Improving air quality.
- Reducing the heat island effect, thus keeping the Central City cooler.
- Increasing urban green spaces for rest, recreation and beauty.
- Providing urban habitat for birds and pollinators.
- Protecting a roof’s membrane from sun exposure while increasing its functional life.
- Managing stormwater in densely developed areas while also allowing more flexibility in building and site design.
Toronto is well known for its ecoroof requirements for new development, while other cities like Chicago and San Francisco have a mix of requirements and incentives.
The proposed standard for ecoroofs in Portland’s Central City applies to new development in the CX, EX, RX and IG1 zones and only to buildings larger than 20,000 square feet. The building’s roof top must be covered with at least 60-percent ecoroof with a few exemptions for solar panels, mechanical equipment and fire evacuation routes.
Public testimony asked for the regulation to be applied to smaller buildings, to cover more of the rooftop, and to allow more space for tenant amenities, like rooftop patios. Others were concerned about the cost of the regulation and asked the Commission to consider other types of roofs like white roofs or cool roofs.
PSC Action: The PSC supported the requirement in the Proposed Draft, but expanded the stated purpose to include managing stormwater, reducing urban heat island effects and improving air quality.
In addition, Commissioners requested further research to evaluate other types of green roofs, such as roof top gardens and landscaped areas, to see if these could meet the stormwater requirement. They also requested research on the use of ecoroofs on wood frame buildings.
After the Central City 2035 hearings in summer 2016, the PSC requested an analysis of the cumulative cost that proposed new regulations could add to the price of new development so they could consider both the public benefits as well as their potential impact on the feasibility, scale and pace of development in the Central City. Portland Development Commission (PDC) and BPS contracted with EcoNorthwest (EcoNW) to analyze the impact of the following four new policies on future development:
- Changes to Parks System Development Charges (SDC)
- New Construction Excise Tax (CET)
- New Inclusionary Housing Program requirements (IHP)
- New green building requirements (including low carbon building registration, and standards for bird safe glazing and ecoroofs)
Findings from the study indicated:
- Parks and Recreation SCDs and the CET could add 0.97 and 0.01 percent, respectively, to development costs.
- New inclusionary housing requirements could add up to 3 percent to development costs. However, the Housing Bureau would offer offsets for projects in the Central City, including a 10-year property tax exemption on all residential units (market rate and affordable). This would more than make up for the additional cost of IH requirements.
- Green building requirements would make up approximately 1 percent of total project costs but could be 1.5 to 3.5-percent higher, if a project pursues full low-carbon building certification.
Staff indicated that while these additional project costs may have an impact, overall project feasibility is much more affected by construction costs, lease rates, land values and financial costs.
The next PSC worksession will be on February 14, 2017. The agenda and materials are located here. More information about other work sessions is here.