House conversions to add commercial space usually don't trigger Bureau of Transportation System Development Charges unless the house is larger than 3,000 square feet in floor area.
BES charges a Sanitary SDC for commercial projects whenever a development permit includes the addition of one or more new plumbing fixtures. (A new "fixture" is a sink, toilet, dishwasher, floor drain, etc.).
Different plumbing fixtures are charged at different rates. Call BES at 503 823-7761 for more information.
For the Water Bureau, an SDC is based on the size of meter installed. If your new project will include the addition of plumbing fixtures, a larger meter size may be required and an SDC charged. Portland Water Bureau staff is available to answer your SDC questions at 503-823-7368 or view more information online.