Planning Guide for Underground Quonset Hut Buildings

Underground Quonset building interior

One question we are asked a lot is 'can you bury a Quonset building underground?' The simple answer is yes you can. But, there are a number of factors you should be aware of before setting into a project like this. These being:

  1. Structural Integrity: You will need to ensure that the structural integrity of the steel arches is not compromised in any way once the structure is covered in several tonnes of earth. Some users have taken the extra precaution of spraying the completed building with shotcrete for added strength. The earth that is going to cover the building should also be equally applied and gradually built up around the building so as not to place an uneven amount of stress on one side of the Quonset. The thickest available steel is also recommended, in most cases this will be 18-gauge (ga) steel.
  2. Slippage: To prevent the building from moving over time some have recommended placing structural steel ties around the building and then attaching these to the finished structure.
  3. Insulation: For added insulation some building enthusiasts have also applied a layer of spray foam to the finished Quonset structure prior to backfilling.

What are Underground Quonset Huts Used For?

Some end-uses that we have recently encountered include:

  • Camouflaged hunting cabins
  • Energy efficient homes in extremely cold climates
  • Back 40 'Man Caves'
  • Zombie proof houses
  • SHTF houses & shelters


It should be noted that neither BuildingsGuide or its suppliers recommend placing a Quonset hut underground as the buildings are NOT engineered for this purpose and no engineering studies have been carried out of this type of application. It should also be noted that if a building is buried underground that it will:

  1. VOID the Quonset building manufacturers warranty
  2. Contravene all building codes, and
  3. Will most likely be uninsurable

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arches on a Quonset structureq-model arch buildingQuonset underground building


A Quonset hut is a steel building that is designed with an arched top or roof. They have several distinctions from their straight walled cousin.

Quonset huts are generally less expensive than steel buildings with straight walls. They can cost up to 30% less depending on the design you choose. They are also known to be sturdier in locations where there is risk of earthquake or hurricane, as the arch lends strength to the design.

The arched top style comes in three different shapes. 

The Q-model is basically an arch all the way from the base and across the roof to the other side (like a half circle). This is the least expensive of all steel buildings and comes in sizes ranging from 20 feet wide to 100 feet wide.

The S-model is similar to the Q-model, except that the side walls are straightened, leaving the roof in an arch or curve. This is a good application for warehousing or storage, as the straight walls add space for stacking and shelving that the Q-model does not. S-models are slightly more expensive than the Q.

The P-model has a gable-styled roof (like an arch with a pinch in the center). The side walls are straight and tall compared to the S- and Q-models. The attractive shape of this building makes it a popular choice for installing in the backyard – such as a garage. The P-model is more expensive than an S-model, but still cheaper than a similar sized straight walled building.

Quonsets were created for military purposes in 1941. The Fuller Construction Company near Quonset Point, Rhode Island, produced them for the navy. Originally, they were 16' x 36' with curved steel T-ribs. The floor was tongue and groove and its exterior was galvanized metal. At the time—the World War II era—they became popular for both military and civilian uses.

They came to represent the postwar economic and demographic boom. Some are even listed on the National Register of Historic Places.

On the plains, these buildings were commonly used for machine sheds, yielding to somewhat more refined commercial steel buildings as time went on. They also appeared on college campuses as administrators were faced with exploding demands for higher education, thanks to the veterans’ educational benefits in the GI Bill. The Quonsets helped to house students and sometimes even faculty. Some were obtained from military surplus distributors but some were new.

Today they’re being produced and used for storage sheds, especially on farms and ranches; for garages, particularly for large vehicles; and workshops. They are ideal for storing and protecting grain, livestock, and all kinds of farm and ranch equipment. Because they are much stronger than I-beam buildings or pole barns and easily expandable to any length, they have been popular on farms and ranches for over forty years.

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