3LDK apartments typically range from 60 m² of space to as much as 100 m² of space or more. On average, a 3LDK unit in Tokyo and Yokohama is about 70 m² to 80 m², has a separate toilet and bath, kitchen with a 3-burner stovetop, 1 larger bedroom and 2 smaller bedrooms, a larger balcony, and a dressing room/washroom with a vanity and space for a washing machine. Older 3LDK units may tatami mats in at least 1 or all 3 bedrooms, while newer properties tend to have flooring instead with at least 1 bedroom having tatami mats. Newly built 3LDK units may have a walk-in closet in the larger "master bedroom" with direct access to the balcony from that bedroom.

3DK units are not as common as a 3LDK unit, and tend to be found in much older buildings. In some cases, a 3DK may be no larger than a 2LDK unit. In many cases, some owners convert their 3DK into a 2LDK when the kids move out or if they want to use the property as an investment property.

A typical tenant is a married couple with children. Although small my western standards, 3LDK units are popular among the foreign community who have kids and need to be close to the city center for accessing work and international schools. 

A 3LDK is often a permanent home that offers many more conveniences in terms of access while having the same amount of space or even more space than a newly built house in the suburbs. 

Buyers of this type of property often buy this property as a permanent home until a nursing home becomes necessary or the property is sold after being inherited often to cover the cost of inheritance tax.