It is probably going to be one every year at most so you should not take risks by using low quality canvas. Basis of measurement: The office is measured from window to core area, including columns, but excluding common areas, washrooms, and platforms, if some. https://www.pressadvantage.com/story/65917-cool-blew-inc-announces-expansion-of-hvac-and-plumbing-services-in-phoenix-arizona