Yes, with certain limitations. Most home-based businesses and home occupations are permitted as an accessory use in residential units subject to certain conditions (see Sec. 17.22.090 OMC, linked here). Animal hospitals, beauty and barber shops with over one chair, retail sales, mortuaries, repair shops or service establishments, stables or kennels, welding, and vehicle body repair/rebuilding/dismantling businesses are prohibited. Please contact zoning staff to discuss your plans. A permit is not necessary unless construction work will occur on the home.