Cannon Design

After standing vacant for nearly 30 years, the 19,000 sf Power House building in downtown St. Louis opened as Cannon Design’s new regional office. Constructed in 1928 and designated as a landmark by the National Historic Register, the Power House provided coal-fired steam heat to a dozen downtown buildings until its decommissioning in 1980. Although the building’s exterior shell and original structural steel were fundamentally sound, significant imagination and rigorous design analysis were required to convert the building for use by a large, thriving design practice. New floors were cantilevered within the building’s massive volume to create a total of 32,000 sf of office and conference space. The floors are set back from the building’s spectacular windows to maintain the sense of transparency and volume. Exterior improvements included creation of a 3,500 sf urban garden and historically accurate replacement of windows in their original masonry openings – with insulated, low-E coated glass to reduce solar gain and air-conditioning expenditures. The building achieved LEED Gold certification in 2009.

Since initial move-in, the building has performed at an exceptionally high level, exceeding even forecasted energy-use predictions. Major contributors to this success are the high-efficiency window system, control systems for day and night cooling, and CO2 sensors that control ventilation. In the first year of occupancy, the building’s energy consumption was 47 percent below the ASHRAE 90.1-2004 baseline. High-efficiency plumbing fixtures and collection of stormwater in an underground cistern for irrigation reduced water usage an estimated 33 percent below baseline.