Under most conditions, the insurance requirements for railings will be the same as the local building codes or OSHA (Occupational Safety and Health Administration) regulations. For residential stairs, the building codes take precedence, while OSHA determines the requirements for businesses. Keep in mind, however, that your insurance company is within their rights to require railings above and beyond the typical legal requirements.
For insurance companies, the decision is about the risks involved. To reduce the risk of liability claims against a property, the insurance company may require railings for only one or two steps. For you, the railing equates to lower premiums because compliance with the request makes insuring the property less risky. Installing a handrail can lower your premiums, even if it is not requested by your insurance company.
Westfire Manufacturing, a company specializing in stair and handrail fabrication, states that stair and handrail requirements will vary by state, county and local ordinances. Most of these ordinances attempt to conform to standards, such as requiring handrails for a rise of more than 30 inches. Handrail widths should be between 1-1/4 and 2 inches wide, another standard most commercial and residential properties must follow. Local laws can exceed the requirements at the state or federal level, but they cannot reduce state or federal regulations. For example, Amherst, Massachusetts requires handrails to be a minimum of 36 inches high, which is standard for most residential and commercial installations, conforming to federal OSHA regulations.
Washington state laws specify that at least one rail must be provided on stairs wider than 30 inches, preferably placed on the right-hand side of someone going down the stairs. The state laws go on to say that any steps or stairs with more than four risers must be furnished with railings along any open sides, and door openings must provide for at least 20 inches of clearance when the door is opened. Insurance companies may even specify that stair landings be furnished with horizontal railings.
Most of these laws conform to standards, such as requiring handrails for a rise of more than 30 inches. Insurance companies can accept the local laws or require handrails for rises of any size. Insurance companies cannot require less than what is specified by local and state laws, but they can require additional safety measures. Local laws do not experience the direct cost of liability injuries related to handrails, but insurance companies do, and are within their rights to request additional safety measures if they are deemed necessary to reduce a potential danger.