Originally, most fire and building codes were written and adopted at the local government level. As a result, there were many differences in code provisions from community to community. Local problems often resulted in unique code provisions that were appropriate to the local situation, but not of much use in other communities.
With the development of uniform and model codes and their subsequent adoption by state governments, the common features were applied everywhere. Once the basic provisions were codified into a format and structure that had appeal to both code officials and the builder-development community, their code became “minimum standards.” The model codes were just that—a document that set the minimum criteria that most communities could find acceptable, but not intended to solve every problem everywhere. The developers of model codes left one option to be used: those exceptional situations that require local modifications based on a specific problem could use a specific process to increase the level of a particular requirement.
The solution that was commonly made available in the model adoption process was the development of written “findings of fact” that justified modifications by local code officials. Many state codes identify a specific adoption process. This provision requires that a certain amount of research and analysis be conducted to support a written finding that is both credible and professional. In the context of adopting a supplemental document such as the wildland-urban interface provision, the writing of these findings is essential in creating the maps and overlap needed to use their specific options.
The purpose of this appendix is to provide an overview of how local code officials could approach this process. There are three essential phenomena cited in some model adoption statutes that vary from community to community: climate, topography and geography. Although it can be agreed that there are other findings that could draw distinction in local effects, these three features are also consistent with standard code text that offers opportunity to be more restrictive than local codes.
One point that needs to be reinforced is that the process demands a high level of professionalism to protect the code official’s credibility in adopting more restrictive requirements. A superficial effort in preparing the findings of fact could jeopardize the proposed or adopted code restriction. A code official should devote a sufficient amount of time to draft the findings of fact to ensure that the facts are accurate, comprehensive and verifiable.
CLIMATE. The average course or condition of the weather at a particular place over a period of many years, as exhibited in absolute extremes, means and frequencies of given departures from these means (i.e., of temperature, wind velocity, precipitation and other weather elements).
GEOGRAPHY. “A science that deals with the earth and its life, especially the description of land, sea, air, and the distribution of plant and animal life including man and his industries with reference to the mutual relations of these diverse elements.” Webster's Third New International Dictionary of the English Language, Unabridged.
INSURANCE SERVICES OFFICE (ISO). An agency that recommends fire insurance rates based on a grading schedule that incorporates evaluation of fire fighting resources and capabilities.
TOPOGRAPHY. The configuration of landmass surface, including its relief (elevation) and the position of its natural and man-made features that affect the ability to cross or transit a terrain.
There are two types of climates: macro and micro. A macro climate affects an entire region and gives the area a general environmental context. A micro climate is a specific variation that could be related to the other two factors, topography and geography. A micro climate may cover a relatively small area or be able to encompass an entire community, as opposed to another community in the same county.
Climatic consideration should be given to the extremes, means and anomalies of the following weather elements:
3.Precipitation and flooding conditions.
4.Wind speed and duration of periods of high velocity.
6.Fog and other atmospheric conditions.
What is essential in creating an wildland-urban overlay are the data that suggest the existence of critical fire weather in the jurisdiction.
Topographic considerations should be given to the presence of the following topographical elements:
1.Elevation and ranges of elevation.
2.Location of ridges, drainages and escarpments.
3.Percent of grade (slope).
4.Location of roads, bridges and railroads.
5.Other topographical features, such as aspect exposure.
This information becomes an important part of creating an analysis of wildland-urban areas because topography and slope are key elements (along with fuel type) that create the need for specific ignition-resistance requirements in this code.
Geography should be evaluated to determine the relationship between man-made improvements (creating an exposure) and factors such as the following:
1.Fuel types, concentration in a mosaic and distribution of fuel types.
2.Earthquake fault zones.
3.Hazardous material routes.
4.Artificial boundaries created by jurisdictional boundaries.
5.Vulnerability of infrastructure to damage by climate and topographical concerns.
Fuel types are the final component of the findings that suggest the need for identifying wildland-urban areas in a jurisdiction. Review Appendix D for a brief description of the various fuel models that relate to the specific areas under evaluation.
After a person has researched a specific jurisdictional area, the facts should be incorporated into a written document that reflects how these facts relate to the code official’s specific needs. The following is an exhibit that incorporates one such report. It should be reviewed as an example of how a relationship can be drawn between specific facts, fire protection problems and specific code modifications. It should be noted that this is an example only.
The [INSERT TITLE: ADMINISTRATOR] does herewith make findings that certain climatic, topographic or geological features exist in the [INSERT NAME: JURISDICTION], and that those features can, under certain circumstances, affect emergency services. Further, certain code amendments are made to the [INSERT: INTERNATIONAL FIRE CODE] and [INSERT: INTERNATIONAL BUILDING CODE] that are aimed at mitigating, to the extent possible, the impact of those features.
That the [INSERT NAME: JURISDICTION] is situated on the slopes of and at the base of the [INSERT: NAME OF MOUTAINS]. Mountains, with drainages from the [INSERT: DIRECTION] portion of the district, including [INSERT: IDENTIFY LOCAL CREEKS/STREAMS/RIVERS], which, when flooded, could result in conditions rendering fire department vehicular traffic access unduly burdensome or impossible.
Further, the flood conditions described above carry the potential for overcoming the ability of the fire department to aid or assist in fire control, evacuations, rescues and the emergency task demands inherent in such situations. The potential for the aforementioned flooding conditions to result in limiting fire department emergency vehicular traffic, with resulting overtaxing fire department personnel, may further cause a substantial or total lack of protection against fire for the buildings and structures located within the jurisdiction.
That the [INSERT NAME: JURISDICTION] is situated near [INSERT: NUMBER OF FAULTS] major faults, each capable of generating earthquakes of significant magnitude. These are the [INSERT: NAME OF FAULTS]. These faults are subject to becoming active at any time; the [INSERT NAME: JURISDICTION] is particularly vulnerable to devastation should such an earthquake occur.
The potential effects of earthquake activity include isolating the [INSERT NAME: JURISDICTION] from the surrounding area and restricting or eliminating internal circulation due to the potential for collapsing of highway overpasses and under-passes, along with other bridges in the district, or an earth slide, and the potential for vertical movement rendering surface travel unduly burdensome or impossible.
Additional potential situations inherent in such an occurrence include loss of the [INSERT NAME: JURISDICTION] water sources; [INSERT: IDENTIFICATION OF LOCAL SOURCES] would be expected to suffer damage, along with the local reservoirs and water mains; broken natural gas mains causing structure and other fires; leakage of hazardous materials; the need for rescues from collapsed structures; and the rendering of first aid and other medical attention to large numbers of people.
The protection of human life and the preservation of property in the event of such an occurrence support the imposition of fire protection requirements greater than those set forth in the [INSERT: INTERNATIONAL BUILDING CODE OR INTERNATIONAL FIRE CODE].
That the [INSERT NAME: JURISDICTION] includes [INSERT: IDENTITY OF MAJOR TRANSPORTATION ROUTES]. [INSERT: IDENTITY OF ROUTE] is designated by the [INSERT NAME: JURISDICTION] as an approved transportation route for highly toxic and radioactive materials.
The potential for release or threatened release of a hazardous material along one of these routes is highly probable given the volume transported daily. Incidents of this nature will normally require all available emergency response personnel to prevent injury and loss of life and to prevent, as far as practicable, property loss. Emergency personnel responding to such aforementioned incidents may be unduly impeded and delayed in accomplishing an emergency response as a result of this situation, with the potential result of undue and unnecessary risk to the protection of life and public safety and, in particular, endangering residents and occupants in buildings or structures without the protection of automatic sprinklers.
The seasonal climatic conditions during the late summer and fall create numerous serious difficulties regarding the control of and protection against fires in the [INSERT NAME: JURISDICTION]. The hot, dry weather typical of this area in summer and fall, coupled with [INSERT: IDENTITY OF ADDITIONAL CLIMATIC CONDITIONS] frequently results in wildfires that threaten or could threaten the [INSERT NAME: JURISDICTION].
Although some code requirements, such as fire-resistive roof classification, have a direct bearing on building survival in a wildland fire situation, others, such as residential automatic sprinklers, may also have a positive effect. In dry climate on low humidity days, many materials are much more easily ignited. More fires are likely to occur and any fire, once started, can expand extremely rapidly. Residential automatic sprinklers can arrest a fire starting within a structure before the fire is able to spread to adjacent brush and structures.
Seasonal winds also have the potential for interfering with emergency vehicle access, delaying or making impossible fire responses, because of toppling of extensive plantings of [INSERT: TYPE OF TREES] trees. The trees are subject to uprooting in strong winds due to relatively small root bases compared to the tree itself.
The [INSERT NAME: JURISDICTION] is a [INSERT: DESCRIBE TYPE OF REGION] and experiences water shortages from time to time. Those shortages can have a severely adverse effect on water availability for fire fighting.
Fires starting in sprinklered buildings are typically controlled by one or two sprinkler heads, flowing as little as 13 gallons per minute (0.82 L/s) each.
Hose streams used by engine companies on well-established structure fires operate at about 250 gallons per minute (15.8 L/s) each, and the estimated water need for a typical residential fire is 1,250 to 1,500 gallons per minute (78.9 to 94.6 L/s), according to the Insurance Services Office.
Under circumstances such as earthquakes, when multiple fires start within the community, the limited water demands of residential automatic sprinklers would control and extinguish many fires before they spread from building to building. In such a disaster, water demands needed for conflagration fire fighting probably would not be available.
The topography of the [INSRT NAME: JURISDICTION] presents problems in delivery of emergency services, including fire protection. Hilly terrain has narrow, winding roads with little circulation, preventing rapid access and orderly evacuation. Much of these hills are covered with highly nonfire-resistive natural vegetation. In addition to access and evacuation problems, the terrain makes delivery of water extremely difficult. Some hill areas are served by water pump systems subject to failure in fire, high winds, earthquake and other power failure situations.
Efforts to produce comprehensive findings of fact cannot be underestimated. It is an essential step for fire protection professionals to take before risking the proposal to modify a model code with a requirement that is unique to that community. Done properly, a findings-of-fact document will not only support the adoption of a local modification, it may make it virtually impossible to ignore the need without creating a community consequence.