State Farm is expected to increase its average rate for homeowner insurance policies in California by 20% next year, under a proposal approved last week by the Department of Insurance. State Farm insures more than one out of every five homeowner policies in the state and in May announced it would stop accepting new applications for property and business policies in the state. The company cited higher construction costs, a growing risk from catastrophic events, such as wildfires, and challenges related to how it insures its own business when it made the decision.