What is an ADU?

ADU in Los Gatos CA - Living Dining areas - unit over garageWhat is an ADU? This lingo may crop up in housing conversations and leave some hearers baffled, though it’s been in the news quite a lot in recent years.

ADU explained

ADU stands for Accessory Dwelling Unit. In the past, They may have been called:

  • Granny Unit, Granny Cottage, Granny Pod, or Granny Flat
  • In-Law Unit or Mother-In-Law Unit
  • Guest Cottage
  • Carriage House
  • Secondary Dwelling Unit
  • Accessory Dwelling Unit or just Accessory Dwelling

This structure is usually a stand alone, detached building near a primary single family home. It should have its own kitchen, private bath, outside entrance, and a place for a bed (or a Murphy bed or sofa bed, if it’s more like a 1 room studio).

Sometimes, though, the unit is above a garage or attached to the primary home. In 2021 I sold a Los Gatos home that had a guest suite over the garage (see photo above). In short, you could be considering an attached ADU or a detached ADU.

A detached unit cannot exceed 1200 SF of living space. It could be one story, or two!

Junior ADUs

A Junior Accessory Dwelling Unit, often abbreviated to JADU but sometimes called Jr. ADU, is one which is attached and usually smaller in size. The State of California defines them as:

Junior Accessory Dwelling Units … are allowed to be created within the walls of a proposed or existing single-family residence and shall contain no more than 500 square feet. JADUs offer additional housing options. They may share central systems, contain a basic kitchen utilizing small plug-in appliances, may share a bathroom with the primary dwelling, all to reduce development costs.

These are sometimes conversions from large suites or bedrooms in the house and don’t change the overall square footage. The could also be garage conversions.