If a car accident causes damage to a neighbor's house, the type of car insurance you would typically need to use is property damage liability coverage. This coverage is part of your auto insurance and is designed to pay for damage you cause to someone else's property, including a neighbor's home, up to the policy limits. If you are at fault in the accident, this coverage helps pay for the repair costs to their house.

Key Details:

• Property Damage Liability : This is the main car insurance coverage used for damage to another person's property caused by your vehicle. It covers repair costs and is required by law in almost all states.
• If the damage exceeds the limits of your liability coverage or if you do not have sufficient coverage, the neighbor may have to use their homeowners insurance to cover the excess damage, but usually, your liability insurance is the first to cover such damages.
• In some cases, if the driver is uninsured or underinsured, the neighbor's homeowners insurance may cover the damage or the injured party may need to seek legal action.
• Collision coverage on your car insurance does not cover damage to the neighbor’s property—it covers damage to your own vehicle only.

Thus, the car insurance coverage that would need to be used if you damaged part of your neighbor’s house in a car accident is your property damage liability insurance on your auto policy.