Council Seeks to Control Glare From High-Rises

A San Diego City Council committee voted Monday to consider regulating the reflectivity of the mirrored office towers whose gleaming exteriors are proving to be a safety hazard to drivers who travel the local freeways.

The council’s Transportation and Land Use Committee asked staff members to work with the glass industry, builders, architects and others in the building trades to prepare an ordinance that would regulate the degree of a building’s reflectivity and how much of the building’s exterior could be covered by glass.

Staff members have until Nov. 10 to report back to the council with an estimate of the proposed ordinance’s cost. Council members acted after receiving a letter in December from W.R. Dotson, local Caltrans director.

Dotson wrote that his office had received numerous complaints from drivers who say they are almost blinded by the glare from buildings with mirrored glass exteriors. He asked council members to consider this problem in the future when they are asked to approve construction of buildings with this type of window treatment.

Caltrans officials identified 30 buildings in Mission Valley, downtown, Sorrento Valley and Kearny Mesa that shine into a driver’s eyes during the morning or afternoon commute. Some of the best-known reflective office buildings named on the list are the downtown Wells Fargo Bank and the Commonwealth Bank in Mission Valley.

According to the city Planning Department, Honolulu has already adopted a city ordinance that regulates reflective glass used in building construction. The Honolulu measure, which is being reviewed as a model ordinance, regulates the percentage of reflectivity of the glass, the amount of glass used and “the angular relationships between the sun, adjacent buildings, streets and pedestrian systems.”

Reflectivity can be controlled by the kind of glass used in a building. Types of glass called solarban and solarcool create a bright mirror image, while tinted glass has a lower degree of reflectivity and black-colored glass controls glare even better, planning officials said.

According to a Planning Department report, builders of future reflective glass structures could be required to submit solar studies that show the building’s degree and length of reflectivity throughout the day.

The report says that the existing reflective glass buildings were constructed before the glare and light they emit were routinely reviewed through the environmental process. Meanwhile, in the absence of an ordinance, the Planning Department will consult Caltrans officials when a proposed building is to be placed alongside a freeway or heavily traveled road.