Type of Construction & How It Affects Your Premium

Calculating premium for Real Property has many different factors. One of the largest factors involved is the type of construction of the building. Use this article to find out how to determine what type of construction your building is, and what the construction type might mean for your rates.

While there are various styles of buildings and many different building materials available, each structure can be categorized into a certain class, based on the construction of its outer walls and what the floors consist of. Below you will find the different classes used, and how they compare to one another. The list is organized from Most Susceptible to Fire, to Least Susceptible to Fire:

Frame/Brick Veneer:

This type of construction is the most common for homes and small commercial buildings. This class gets its name from having the structure framed and supported by wood or light steel frame. Brick Veneer is part of this category because the brick on these buildings does not actually support the structure. Frame construction is the easiest class to burn down or blow over, but it is also one of the cheapest and most versatile buildings to construct.

Joisted Masonry:

In this class, the building is supported by cinder blocks, precast cement walls, or layered, load-bearing bricks. When cinderblocks are used, a brick veneer façade is often added for visual appeal, but, again, the bricks add no structural support. While the outer walls are masonry, the floors will be wood or light steel joists. Being so, this class is more expensive to build, but is less likely to be burned down or blown over than Frame.


As the name implies, these structures are made of non-combustible materials. This type of construction is typical used for utility buildings and garages, as the structure is entirely made of light steel or similar light, non-combustible materials. These types of structures are harder to burn down than both Joisted Masonry and Frame, but wind resistance varies. These buildings are also less furnished than other structures (no drywall, no insulation, exposed wiring, etc.), making them cheaper to build than the other construction types.

Masonry Non-Combustible:

In Masonry Non-Combustible, the outer walls are made of cinder block, load-bearing brick, or poured cement, while the floors are either heavy steel, poured concrete, or both. This is typically the type of construction used for small to medium sized commercial/industrial buildings. This construction type makes the building harder to catch on fire and sturdier than the Joisted Masonry construction, making it safer.

Modified Fire Resistive/Fire Resistive:

These types of constructions are used for mid-sized to large buildings (E.g. Skyscrapers, multi-floor shopping complexes, etc.) as these buildings typically hold a lot of people and a lot of property. The construction can vary slightly, but these buildings are a step above Masonry non-combustible as fire-proofing techniques have been used on the structure. The jump from Modified to full Fire Resistive depends on the degree of the fire-proofing done. The common fire-proofing test is a multi-factor test. (The class rating is determined by the inside temperature staying below ‘X’ degrees for ‘Y’ or more hours with a fire burning at ‘Z’ degrees. Different variants of ‘X’, ‘Y’, and ‘Z’ create different fire-proofing classes of fire-proofing. )

Why Do These Classes Matter?

Determining the construction of the building is an essential part to receiving a quote. All property-insurers will need to know the construction type before they can provide a quote. This is because each construction type carries a different rate, depending on its susceptibility to certain perils (E.g. Fire). For example, let’s say you have an apartment building you wanted to insure. You think it is Frame construction when it’s actually Joisted Masonry. The premium you’ll pay is going to be higher than if it was properly rated as a Joisted Masonry building. Furthermore, some buildings are too risky to insure if they weren’t constructed with appropriate materials. As an example, some companies will refuse to quote buildings over two stories if they are Frame construction.


Colten Zamrzla, CPCU

Colten first started in the insurance industry in 2010. He then pursued a Bachelor's degree in Finance & Insurance from the University of Nebraska at Lincoln. Once graduated, he immediately started studying for the CPCU and achieved it in just shy of a year. He is solely focused on commercial insurance, able to assist all types of businesses and nonprofits in risk management.

Colten has dedication and passion for his clients and the insurance industry as a whole. He dedicates time to furthering his knowledge on all things business and insurance, and he volunteers for the Independent Insurance Agents of Nebraska, a state-based trade association.