It is Important to know what Type of Building do I have for Purposes of Commercial Insurance
This is a question that will be asked of you by insurance agents and loss control professionals with insurance carriers. It is important that you understand why they are asking and how to determine what type of building you have for insurance purposes.
Let us first look at how to determine what ISO construction class you are in. All buildings must be classified into one of 6 construction classes which is broken down for you below. Classification is based on 2 factors.
The first is Building Elements. This is the materials used in construction of your structure. Examples are wood, steel, or masonry. The areas that are looked at be built with these materials are the structural frame, interior and exterior load bearing walls, interior and exterior non load bearing walls, floor construction, and roof construction.
The second factor is Fire-Resistance Rating. All the building material used in construction has a rating which means the time it stands up to a fire and how quick it spreads to other areas. Your building is going to be rated by the weakest aspect. For example: if you have a wood roof vs a metal roof you would be rated in a higher premium bracket due to the fire rating of the wood material used to build the roof. Wood burns quicker and does not contain fire like metal.
In summary to determine the ISO class we must know what type of roof, floor, walls, structural frame, and fire rating of building materials. Now let’s determine which class you may fall into.
ISO Class 1 is Called Frame. This is one of the most common classes used in construction. You will have wood walls, brick veneer (single layer for appearance only), stucco, and a wood roof that is not typically anchored. Primary examples of this class would by a residential home or offices that may have been converted from homes to commercial locations.
ISO Class 2 is Called Joisted Masonry. This class consist of concrete or cinder block load bearing walls. Could have structural brick along with a wood roof. The roof in this class is also typically not anchored. Examples of this are residential homes but also single story office building locations that do not have flat roofs. Main difference between this and Class 1 Frame is the increased amount of concrete, cinder, brick for load bearing and structural purposes whereas frame uses wood for these areas.
ISO Class 3 is Called Non Combustible. Construction of this type of structure will contain a minimal amount of wood. Load bearing walls will be brick, stone, concrete tilt up, or metal. Frame is generally steel. The roof is a steel deck which is flat or has a slight slope. Roofs could also be metal. The roof is anchored to the structure with metal bolts. Examples of this class would be warehouses, storage facilities, and manufacturing plants.
ISO Class 4 is Called Masonry Non Combustible. This structure is a class above ISO Class 3 because it reinforces its load bearing walls. They are usually tilt up concrete, precast concrete masonry, or concrete blocks on steel. The roof systems are steel decks, poured structural concrete on steel decks, or metal. The roof is also anchored by metal bolts. Examples of this class would be schools, shopping centers, outdoor malls, and warehouses, etc.
ISO Class 5 is Called Modified or Semi Fire Resistive. This class has semi wind resistive walls made out of protected steel or precast concrete tilt up. The roofs are similar to class 3 and 4 in which they are a steel deck or poured structural concrete. The roof is anchored by metal bolts. The heavy construction nature of this structure makes leads us to examples such as high rise office buildings.
ISO Class 6 is Called Fire Resistive. This is the strongest class possible. Walls are concrete, very well protected steel. Floors are 4” cast in place concrete, precast concrete or protected steel. The structure is wind resistive. Roofs are poured structural concrete and anchored by metal bolts. Office buildings are another example of this class along with parking garages.
The key thing to remember in determining your building class is you are only as strong as your weakest element. This is a quick overview of the classes and if you are looking for more details or have questions than reach out to your agent or insurance carrier and they will be able to help you out.