I'm brand new to the forum and this is my first post. My son and I are rebuilding an 1886 vintage Victorian home in Denver. We will install a new 36" wide interior stairs to the non-habitable (74" ceiling height) basement, where the furnace and hot water heater are located. What is the required minimum width for a stairway door to the basement? Installing a 36" door would present problems. We could install a 32" door, but a 30" would look better. This is the only access to the basement.