21st Street Accessory Dwelling Unit Posted on June 10, 2020June 12, 2021 by Streitberger Home Design 1114-W-21st-St-ADU-1 1114-W-21st-St-ADU-2 1114-W-21st-St-ADU-3 Posted in ADU - Accessory Dwelling Unit and tagged Accessory dwelling unit, ADU.