A standard homeowner’s policy protects against fire, lightening, wind, storms, hail, explosions, riots, aircraft wrecks, vehicle crashes, smoke, vandalism, theft, breaking glass, falling objects, weight of snow or sleet, collapsing buildings, freezing of plumbing fixtures, electrical damage and water damage from plumbing, heating or air conditioning systems. Such policies are called "all risk" policies, which cover everything except earthquakes, floods, war and nuclear accidents. A basic policy can be expanded to include additional coverage, such as for floods and earthquakes and even workers' compensation for servants or contractors. Home-based business-coverage, an increasingly popular rider, does not cover liability associated with the business. Insurance experts recommend that homeowners obtain insurance equal to the full replacement value of the home. On a 2,000 square foot home, for example, if the replacement cost is $80 per square foot, the house should be insured for at least $160,000.