Sq ft pricing for commercial

I am bidding on a commercial building that is roughly 560ft long by 150ft wide by 36 feet tall so roughly 51,000 sq ft of area to clean. It will need to be soft washed with a roof mix as there is some organic matter randomly present on the surface. The exterior is a synthetic stucco like Dryvit or similar. Does anyone use a sq ft price to price these jobs like $0.135 per sq ft?