Energy use in buildings throughout North America has attracted significant attention over the past decade. In cold marine climates, rainwater management is also a critical aspect of the building enclosure and energy performance. Various drainage practices used for low slope inverted roofing are often designed without quantified data available regarding the cold rain affects on the thermal performance of the systems.
ETFE, the fluorocarbon-based polymer ethylene tetrafluoroethylene, is quickly gaining popularity in North America and being used on some of the continent’s most prominent projects. ETFE was developed for architectural purposes in the 1970s, and since that time, mainstream use of ETFE in construction projects has been largely limited to Europe.
The Landscaped Podium
As part of a building’s exterior element, landscaped podiums or waterproofed plaza decks provide an aesthetically pleasing common space for the enjoyment of their users. In addition to providing much needed green spaces on concrete structures, podiums that incorporate large softscape areas aid in the building’s water management strategy by retaining and slowly releasing storm water during a heavy rain event.
Attic ventilation is a firmly established requirement for residential wood-framed buildings. Attic ventilation is cited to be a benefit for moisture control, reducing cooling loads in hot climates, minimizing ice dams in cold climates, and extending the service life of roof materials by reducing surface temperatures. There is an ongoing debate on the real significance of some of these benefits and mandatory venting requirements.
The development of a seven-story office building with a four-story underground parking garage, located adjacent to the Alaskan Way viaduct just south of downtown Seattle posed unique challenges. The project was situated on a sensitive site with specific soil conditions and a high water table. The team identified early on the need to develop strategies to minimize the risks associated with the site conditions both during construction and over the long term. The site conditions along with the project requirements were all considered in the selection of the appropriate shoring system and waterproofing system for the structure.