You would 1st check the zoning chapter for your zone, such as Chapter 11-3 for R1 for single-family residential. If your property does not meet the minimum requirements for a lot in that zone.
For instance, if your property is in the R1-7 zone but it is less than 7,000 square feet in size or less than 70 feet in width), your property is entitled to some breaks on the setback requirements, which can be found in Chapter 11-21 for substandard lots of record.
These chapters address the principal building on your property (the house), and any additions to it. There are different setback requirements for accessory buildings, found in Chapter 11-20 of the Boulder City Municipal Code, Title 11 - Zoning