Building Code

Building codes are regulations that govern the design, construction, and maintenance of structures to protect public health, safety, and general welfare as they relate to the construction and occupancy of buildings and structures. 

Building codes become the law of jurisdiction when formally enacted by the appropriate governmental or private authorities. Codes can be adopted on a statewide level with local jurisdictions adopting more stringent requirements than those required by the state, or states can adopt a mini-maxi code that does not allow local jurisdictions to enforce a code more or less restrictive than the state code. States may also adopt a statewide building code but not require the adoption at a local level.

Most jurisdictions in the United States use the International Building Code (IBC), which is a model code developed by the International Code Council. The IBC is the codebook for commercial construction while the International Residential Code is used for residential construction. Under the umbrella of the IBC, there are numerous other model codes that specifically address plumbing, mechanical, electric, etc. Revised versions of the ICC are released on a three-year cycle, allowing jurisdictions to adopt the most up-to-date version. Often, codes are adopted every other cycle to maintain a standard set of codes for longer than three years. Building codes are usually administered by a building official or, especially in smaller jurisdictions, a designee.

Codes provide:

  • Standards to ensure buildings and structures can withstand hazardous conditions;
  • Protection of the financial investment of the building and property value;
  • Protection of public health and safety; and
  • Predictable standards for the entire jurisdiction.

As it relates to wildfire, the IBC addresses fire prevention through construction and design, whereas a fire code addresses how that building will function safely once constructed. Building component requirements within a mapped or identified hazard area can be required and enforced through the building code. If construction does not meet the building code requirements, the building official can deny the building permit application or not allow occupancy of the structure.

Community Examples

Boulder County, Colorado – Boulder County amended its 2015 building code to require that all single- and two-family dwellings within a designated wildfire zone be built using ignition-resistant construction. If development goes through a site plan review process, additional requirements for wildfire mitigation may be required.

Link to map

Portola Valley, CA – Due to significant wildfire risk, recent wildfire activity, and pressure from the State of California to increase housing density, Portola Valley recently passed a “home hardening ordinance” which requires all new construction or significant remodels to meet updated standards that are more restrictive than those required by state law (SFM, Chapter 7A). 

The home hardening ordinance:

  • Prohibits wood shake and shingle roofs, even if they are treated.
  • Clarifies and eliminates combustible exterior wall coverings. Wood, shingle, and wood siding would not be allowed.
  • Eliminates the option of using 1/16” mesh openings in lieu of more effective, listed, ember-resistant vents for attics and underfloor spaces.
  • Adds requirements to protect the underside of deck structures with noncombustible exterior enclosures when the deck is 4 feet tall and lower.
  • Adds requirements for decking material (walking surface) to be non-combustible.
  • Requires fences, gates within 10 feet of the home, noncombustible gazebos and similar structures within 50 feet of a home, and trellises over 120 square feet in area to be noncombustible.