A housebarn (also house-barn or house barn) is a building that is a combination of a house and a barn under the same roof. Most types of housebarn also have room for livestock quarters. If the living quarters are only combined with a byre, whereas the cereals are stored outside the main building, the house is called a byre-dwelling.

There are several styles of housebarns. One style is a building where the barn portion shares a wall with the house portion. Sometimes the house portion will extend into part of the loft on the second storey of the barn portion.

Another style features the barn as the lower portion of the building and the house as the second floor such as the Black Forest-style house.^[why?] Similarly but for different reasons, some defensive house structures such as the bastle house and some tower houses combine animals on the ground floor and living quarters above, a security measure against raids. For example, bastle houses are found along the Anglo-Scottish border, in areas formerly plagued by border Reivers.

Housebarns were built beginning in prehistoric times after people discovered that the body heat of animals helps to warm human living areas. The ancient four room house is an Iron Age type highly identified with the ancient Israelites.

Living with livestock in the combined building also allowed people to be able to prevent thieves from stealing their animals. Housebarns were developed in western Europe, Scandinavia, and the British Isles and continued being built into the 19th century. The first three designs in the 1839 edition of An Encyclopædia of Cottage, Farm, and Villa Architecture and Furniture... were for combined living space for the farm family and their animals. Immigrants to North America rarely built housebarns; they typically divided the barn and house functions into separate buildings although part of New England in particular is known for its connected farms.

Owners have stated that they find it convenient to not have to walk outside while feeding or watching a medical issue such as birth of animal young. They often can hear the animal noises, which can be disruptive or helpful when an animal has problems.

One American builder estimates that 5% of its buildings have an attached living area, some of which are small apartments. They cite several concerns about building a housebarn. Since fewer people are interested in owning a living quarters attached to the house, housebarns have a more limited marketability. This causes lending institutions to be less likely to grant a loan. Bankers are less likely to accept housebarns as collateral. Housebarns are more costly to insure since they are treated like barns, which have a higher risk of fire. The house portion may get unwanted pests that are common in barns like mice, flies, and birds.

In Belgium, most of farms were housebarns, referred to as Langgevelboerderij (long-facade farm) in Dutch and simply cinse (farm) in Walloon, then ferme in French. They were located in the heart of the village until the early 1950s. At that time, barns, at first, then stables began to be built outside the main building, or even outside the village.