Apartments are broken down into classes (Class A, Class B, Class C and Class D) relating to tiers of quality, location and amenities. The classification is a breakdown of space within a general market area, so what is a Class A space in one market might not be considered Class A in another. Apartment property types include mid rise buildings, garden apartments, townhouses, and multi-unit apartments. Apartment leases are generally short term ranging from six months to one year and occasionally month-to-month. Modified gross (MG) lease is the most common type of lease with the tenants responsible for interior maintenance and some utilities. Apartment vacancy rates tend to be lower than many other property types. West Valuation has provided various apartment appraisals throughout San Diego and Los Angeles.