Frequently Asked Questions

General Questions about Quonset Huts

Can I put side windows into my existing Quonset hut?

Cutting door or window openings into the sides of any Quonset hut severely weakens the structure. This weakness must be compensated for, or you risk total structural failure and collapse of the hut. When you order a brand new Quonset hut building and include side openings in your order, the factory will account for the openings in their engineering, and the structure should be sound if erected carefully following their instructions.

To add side openings to an existing building, the safest way to do it is to contact the factory that originally engineered the structure, and ask them. They should be able to review the records and structural calculations for your building, and in many cases the will probably be able to sell you a window kit to match your building’s arch profiles that will safely accommodate the structural requirements. They might need you to replace the arches on either side of the new window with heavier gauge arches to help compensate for the weakness induced by the window hole. In our Headquarters Hut at the Quompound, the arches on either side of the windows are heavier gauge than the rest of the building, to help compensate for this weakness. This is pretty common with side windows from what I understand.

The thing you have to realize about the structure of a Quonset hut, which isn’t immediately obvious, is that in addition to the gravitational force of the building pushing straight down, the arched shape also induces an outward thrust at its base. The slab foundation that is most commonly used with a Quonset hut is actually under tension, serving to tie the outer foundation lines and preventing the bottom of the arch from springing outward. Imagining the base of the arch wanting to spring outward, now imagine cutting away two or three of the arches to make a window opening. You have now created a section of the Quonset shell where, at the top of the window, there is nothing to resist the outward push naturally exerted by the arch shape.

I have seen, with my own eyes, a Quonset hut that collapsed because of an improperly engineered side window. Thankfully no one was hurt; it was not a pretty sight. Cutting holes in a Quonset hut without involving the original factory that manufactured it is not a risk that I would advise anyone to take. The collapsed building was not one of my own projects or clients; I was simply allowed to view it before it was demolished and replaced.

So again, side windows can be added to existing Quonset huts, but I would never attempt it without the full cooperation of the original factory engineers.

When I order my Quonset hut what gauge should I specify?

What gauge of steel a person should order when purchasing a Quonset hut comes up from time to time in the Facebook group.  The sheet metal panels that are formed at the factory come in various gauges, where “gauge” is referring to the thickness of sheet metal the building panels are made from.

The thinnest gauge Quonset huts come in is typically 22 gauge, and the heaviest is generally 16 gauge. Sometimes they will go as thick as 14 gauge. Roughly speaking, you can imagine the gauge as a fraction of an inch. This isn’t technically accurate, but it does help you get a mental image of what we’re talking about. For example, 16 gauge is roughly 1/16 of an inch. The higher the number, the thinner the metal.

Here’s the crux of it though: you do not need to be preoccupied with attempting to determine this yourself before speaking with a salesperson. Here’s why: there are many factors that go into determining the gauge of your building. Some of the factors in determining proper Quonset hut gauge are:

  • What shape you are considering. Q models are strongest; S are less strong than Q models; A models (sometimes called P models) are weakest.
  • Size of the building. A larger Q model will need to be a heavier gauge to meet the same structural loads, versus a smaller Q model under the same site conditions.
  • What are the site conditions where you will be building? Are there snow loads, high wind loads, or are you in a seismic zone? Many places have some combination of these. These loads play a major factor.

Your sales person, in consultation with the factory engineers if necessary, will be able to determine the minimum gauge that will suffice to meet your requirements based on these, and possibly other, factors that need to be taken into account. You can always opt to order your Quonset building in a heavier gauge if you want to (if you want to spend the extra money, that is), but asking some random person such as myself or putting the question out there in an online forum or Facebook group isn’t going to yield any useful information, in my opinion.

Instead, here are some avenues of research and due diligence that you can and should pursue instead, before initiating a conversation with a manufacturer:

Local building code requirements: Contact your local permit office and tell them you are planning on ordering a steel building and what are the local requirements? Snow load, wind load, seismic design, and frost line depth are all important to know. In theory the manufacturer is responsible for getting this stuff right, but it’s extremely important, and any errors here will cause you endless headaches later. In addition to the specific items mentioned above, be sure to ask them if there are any other local requirements that need to be met.

Your building’s interior design: I highly, highly recommend having your design well worked out before finalizing your order. It is far too often that I am contacted by someone who wants help from me with their design, but upon speaking with them further I learn that they were so excited about some “discounted” or “overstocked” or “clearance” building, or a “cancelled order” from a manufacturer, that it was just too good of a bargain for them to pass up. But it turns out that the amazing bargain building they got talked into wasn’t really right for their needs. Sadly, this is actually a pretty common occurrence. And once you sign a contract and pay your deposit on the building, good luck getting any kind of refund or flexibility with respect to changes.

Do your due diligence! Then buy the building that really suits your needs.

What is the best heating/air conditioning (HVAC) system for a Quonset hut home?

It may surprise you to learn that the HVAC (heating, ventilation, and air conditioning) system for a Quonset hut home isn’t necessarily any different from a conventional home with a similar size and layout, for the most part. The determination of what type of system will work best for you will have much more to do with the overall size of your home, its layout, your local climate, your budget, and other possible local considerations such as the applicable energy code, if you have one where you will be building.

For some homes, a traditionally ducted, central furnace/AC system will be a good choice. For smaller homes, such as an open-concept studio or open plan one-two bedroom home, a ductless mini-split system could be a good option.

For heating, a geothermal or ground source heat pump will cost more to set up than a conventional heat pump would, but you basically never have to buy fuel (although the system will require some electricity to run).

Many Quonset hut homes feature a lofty, open great room that takes full advantage of the large, clear spans these buildings are capable of. These types of spaces can be a challenge to heat, but a great solution there is to embed tubing in the concrete slab for a radiant floor system. We have installed this in the Loft House at the Quompound and we absolutely love it. Rather than blow hot air around in the big space, which would be constantly rising up out of human contact, the floor is just gently, silently heated to a comfortable level using the same on-demand propane water heater that creates our domestic hot water. I wrote about that system in detail, here.

Lastly, a wood stove or pellet stove can be a good option for heating. I wrote up a separate FAQ on those, so be sure to check it out also.

Can you install a wood stove in a Quonset hut home?

A wood stove or pellet stove can be a good option to heat a Quonset hut home, with a few caveats:

First, a pellet stove is much, much easier to vent than a wood stove. Pellet stoves are extremely efficient and part of their efficiency is that they are extremely clean burning. Many, if not most, pellet stoves can be vented straight through an exterior wall with just a vent cap on the outside of the wall, with no requirement for a full-on chimney like a wood stove would have.

Second, with either a traditional wood stove or a pellet stove, you will want to position it on an end wall. Placing a traditional wood stove or pellet stove somewhere along one of the sides of your Quonset hut will create problems for venting it. Think about it this way: when it rains, all that water is pouring down the sides of your hut. If you are trying to penetrate the side of the hut for a flue or chimney, you are basically putting that hole right along a waterfall. The end walls are a far better location.

Third, a wood stove chimney, if it is to pass through the Quonset arch, will require a hole about 10 1/2″ in diameter. This may be a larger hole than your Quonset hut manufacturer will allow without voiding your warranty. If you plan to install a wood stove, I would strongly urge you to make it clear to your salesperson at the beginning of your discussion of the building with them. It might be possible for them to accommodate it in your building kit, but there could be issues, especially with larger buildings. Or they may need to adjust the gauge of your building (or make one or two arches heavier than the rest) to compensate for the hole. Cutting holes in the building is a big deal and is definitely something to be take seriously.

If you do end up penetrating the arch for a wood stove chimney, you will be much better off doing so at the very dead center of the arch, rather than to one side or the other. The reason, again, has to do with water intrusion. At the top center of the building, virtually all the rain water is going to be flowing down the sides and away from the chimney flue. This gives you a much better chance of keeping water out.

Do I need to insulate my Quonset hut?

Short answer: Yes.

Some manufacturers have salespeople who claim their buildings don’t require insulation; that their buildings are somehow self-insulating or that they naturally reflect the heat away and keep the inside cooler in summer than the outside temperatures. I have heard that they claim up to 20 degrees cooler in some cases.

I’m here to tell you this is a completely bogus sales pitch. Quonset huts are amazing buildings, and there are so many good things to say about them that this “insulation optional” hogwash is totally unnecessary and whoever gives this sales pitch to a potential customer should know better. They should sell these buildings on their merits, not on made up nonsense.

Our Quonset huts, before we insulated them, were routinely a minimum of 10 degrees hotter in summer than the outside temperatures. A well insulated Quonset can probably out-perform a comparable stick-built home, energy wise, in my opinion, but an uninsulated Quonset is unlivably hot in summer and cold in winter. The truth is there is ZERO insulation value to the metal shell.

The best insulation for a Quonset hut is closed cell spray foam. The amount varies based on your climate and local conditions, the building code where you are, and your budget.

Can you build a Quonset hut on a stem wall instead of a flat slab?

Placing a Quonset hut on a stem wall is not uncommon, but takes a little bit of planning ahead. In some cases your manufacturer can provide you with a foundation design for a relatively low stem wall. In some cases an engineer hired by you can design you a foundation that is more efficient in its use of concrete and rebar, versus a factory engineered stem wall design, such that the hiring of the engineer pays for itself.

One thing you have to realize about the structure of a Quonset hut and its foundation, which isn’t immediately obvious, is that in addition to the gravitational force of the building pushing straight down on the foundation, the arched shape also exerts an outward, lateral thrust at its base. The slab foundation that is most commonly used with a Quonset hut is actually under tension, serving to tie the sides of the arch at the base, preventing the bottom of the arch from spreading or springing outward. Depending on the size of the hut, some of the factory foundation designs I have seen actually require quite a bit of extra rebar in the slab, helping the concrete to compensate for this outward thrust.

In order for your engineer to be able to design your foundation properly, you will need to get “reactions” for your building from your manufacturer, in lieu of ordering your building with their standard foundation design. These reactions consist of a table of engineering data that is unique to your building, which your engineer will use to design the foundation to resist the outward thrust and meet all relevant safety codes. You need to make it clear to your salesperson that you will need reactions for a custom foundation. Typically, you will also want to make sure to order base plates with the building, since the alternative to base plates, the “keyway foundation”, isn’t really suited to a stem wall setup.

It will definitely be less expense and trouble to just go with a standard foundation design if at all possible. But if for whatever reason you need to go with a custom foundation design, such as setting the building up a bit and/or allowing for a crawlspace underneath a wood framed floor, it is definitely doable, as long as you get the reactions and get a qualified local engineer on your team. Another scenario is a sloping site, where it might be simpler to pour side walls to set your Quonset hut upon, rather than grading/retaining a large area in order to do a more conventional slab foundation.

Can my Quonset hut have a crawl space or basement instead of a slab foundation?

Short answer: Yes you can.

If you want a wood framed floor with a crawl space or basement below it, you will need to set the Quonset hut on a concrete wall, which will need to be custom engineered. The Quonset hut manufacturers will only provide a foundation design for a flat slab or low walls. They will not engineer basements, tall walls, or other nonstandard designs. You would need to tell your sales person your intentions at the time of purchase, and instead of a stamped, engineered drawing with the arch and its foundation design, you will get a stamped, engineered drawing with the arch and the engineering data (called “reactions”) that your engineer will be required to use to design the foundation system for your crawlspace or basement scenario appropriately.

Concrete block is not as strong as concrete, and typical block is only 8″ wide, which is too narrow for a Quonset hut base plate. Thus a solid concrete wall is usually your best bet, and I would recommend a minimum wall thickness of 12″, again because of the base plate, although the thickness and rebar specifications should ultimately be determined by your local engineer.

The code minimum height for a crawl space is 18″. This means the arch will need to be lifted up an amount equal to the thickness of your floor framing + 18″, at a minimum. See the other question and answer about building a Quonset hut on a stem wall for more detail on how to go about this and what some of the pros and cons are.

Can you nest two huts, one inside the other?

This question comes up from time to time in my Facebook group.

It seems like a good idea at first but if you have actually built one of these buildings, you would quickly realize its impracticality. When you put a Quonset together, you have to only tighten the bolts “finger tight” on the first pass, and then go back over it to tighten it. So the space you would need in between the outer and inner shell would have to be large enough for a person to physically climb in there.

You are going to lose a LOT of square footage in your building if you are making the inner shell that much smaller than the outer shell. While you’re imagining climbing in there, have a look at this picture of me on the ladder, tightening the bolts on our Q25 workshop. Some of the bolts you can tighten from the top of the arch, and some from standing on the ground at the base plate. But there are a lot of bolts that are in between. How are you going to get a ladder in there, or how are you going to get to those bolts if you are trying to work in this super constrained limited space?

Ok, so by now you’re thinking, “but can’t I just order the arches and somehow just use it like it were installing siding or like ceiling panels?” Yes you could, but now you are going to have to build some kind of framework inside the outer hut, to bolt or screw the inner hut to, to hold it up. Isn’t that the whole idea that you were trying to avoid by adding this inner arch in the first place?

You can buy really high quality corrugated galvalume siding for about $1.50/s.f. that will at least match (or nearly match) the color and finish of your galvalume building. This is a fraction of what you would pay for a second hut to make your ceiling out of.

Sure, with enough ingenuity, you could probably figure out a way to do this. There is no limit to human ingenuity. I personally once thought this shell-inside-the-shell idea was a brilliant solution and I had this very conversation with people at SteelMaster when I was buying my building. Once we had built our first buildings I realize how impractical it would be to try.

Can I get a construction loan from a bank for a Quonset House?

Unfortunately, the answer to this question is usually (but not universally) no. Let’s look at some of the reasons banks dislike loaning on Quonset hut homes.

As part of the lending process, banks look at recent sales prices of similar homes in the same area. “Similar” typically refers to overall square footage, number of bedrooms and baths, lot size, and other general characteristics. Because Quonset homes are atypical, they are going to count “Quonset-ness” as one of their criteria for their comps. Few places have a critical mass of Quonset homes yet.

The Secondary Mortgage Market.
Frequently, when banks originate mortgage loans, they do so with the strategy of turning around and reselling the loans on the secondary mortgage market. They bundle batches of mortgages together and sell them to other banks and financial institutions, who then continue to collect the interest payments etc. as an investment strategy. The buyers (and therefore the sellers) in this secondary market really, really just want everything to be as boring and normal as possible. Not all banks participate in the secondary market, though! Often, credit unions and smaller local banks make home loans with the intent of holding the loan in their portfolio for the life of the loan. These are the institutions you should be speaking with. 

DIY Builds.
A bank’s worst nightmare is handing over hundreds of thousands of dollars to a complete amateur who has never built a house before, and then getting stuck later with a huge mess on their hands when they have to foreclose because the amateur got in over his head. They are a business after all, and they have to contemplate the worst case scenario. Fine then, suppose you’re reasonably skilled, have worked construction before, and are really confident about building your own house? I have total faith in you! Unfortunately, and it’s not personal, the bank does not. Banks can’t take your word for it, because banks don’t take anyone’s word for anything. Their underwriters need every aspect of a loan application to be independently, objectively verifiable. The only way they will be comfortable with your project is for you to have a licensed general contractor on board – and this is regardless of whether it’s a Quonset or a conventional build. In my experience, the vast majority of people looking to build a Quonset House are wanting to do some version of a DIY build, and this fact definitely contributes to the difficulty of getting a bank loan.

Code Compliance & Life Safety.
If you haven’t gotten the picture yet, banks are extremely risk-averse. They will not only want the house built right (see #3 above) they will want minimum standards of safety to be met with your design. Like it or not, pretty much the only way they can check this box is for the house to meet the minimum standards set forth in the building code. One way for them to be more comfortable with this is for the home to have professionally designed plans that are thorough, and well detailed – even better if you have a licensed architect on your team. The combination of a licensed G.C. as described above, with a thorough, well laid out, code-compliant set of plans, are things you should expect any lender to ask for.

Where do I get the coupling nuts & hardware to attach my framing?

You can get the coupling nuts on Amazon, here. The price tends to be very competitive for these on Amazon.

The 5/16-18 threaded rods, as of this writing, tend to be much more common on Amazon in (very expensive) stainless steel. What you basically want are these (Amazon). But you can often pick up the threaded rods at a big box store or even a local hardware store. Check your length! They sometimes sell them precut at 1′ lengths, but that may not be long enough for you, depending on what you are doing and how much depth for insulation you need.

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Working with Earl

What goes into a set of construction drawings for a Quonset hut home?

A full set of construction drawings includes the following:

  • Site plan, showing property boundaries, easements, rights-of-way, required setbacks, locations of septic system & well, and related site information, along with the position of the building on the property;
  • Slab plan, which combines the info from the manufacturer’s foundation plan with the necessary info about plumbing drains and electrical conduits that will need to be set in place before your slab is poured;
  • Floor plans, which give the basic layout and dimensions;
  • Cross-sections through the building, giving heights and vertical relationships of elements within the building;
  • Exterior elevations, primarily showing the end walls along with a complete listing of all doors and windows with their sizes and types (these are called the door and window schedules);
  • Construction details, typically 2-3 sheets of drawings, depending on the complexity of the project;
  • Lighting & electrical plans, showing basic fixture layout and switching. Panel schedules and additional system information can be included if required for permits but may incur an upcharge;

The above are included in a typical set of plans. Additional items that may be required for your permits can include:

  • Energy Code Compliance: Some states have their own system for this, such as California’s Title-24, or Florida or Washington’s respective energy codes, but most jurisdictions follow the energy compliance requirements of the International Building Code. Typically, whatever the method is, the necessary compliance reports can be created by a consultant for a few hundred dollars, and we can help you coordinate this to go with the plans.
  • HVAC System Design: In some cases this is linked to the above energy analysis; in many cases the permitting authority will require what are termed the Manual J report, Manual S report, and Manual D report. I found an article online describing these reports, here. These may sound complicated but they are really not a big deal, and my team and I can most likely produce these for you as part of our services if needed.
  • Septic System Design & Permitting: Nearly every jurisdiction I have ever worked in requires a separate permit to be issued for the septic system before they will issue the building permit for the house. The logic goes that they will not issue a building permit for a structure that doesn’t have an approved place to which to flush the waste. Usually the septic permits are issued by some version of a county health department, whereas the building permit will be issued by the building department. The two departments compare notes to see what permits have been approved on which parcels. The septic permitting is something I don’t get super involved in as it usually requires some kind of soil percolation testing and a local septic system designer who knows the ins and outs of the local county procedures. Typically I take location info for the system, as provided by the septic system designer, and incorporate it into the site plan.
  • Solar Energy System Design & Permitting: This one is more similar to the septic as described above; I do not design the system but work with you and a vendor of your choice to coordinate my architectural plans with their solar system design. And similar to the septic, it helps if this is someone who is familiar with the ins and outs of your local permitting requirements.
  • Fire Sprinkler System Design & Permitting: If your project requires residential fire sprinklers, the typical mechanism is for this system to be approved not by the building department, but by the fire department. With few exceptions, nearly all new residential builds in California now require fire sprinklers – even if they are way out in the middle of the empty desert! I will help you coordinate with a local provider.

I am very thorough with my construction documents; it is something I take great pride in.

How long does it take to design and build a Quonset hut house? What is the process?

The length of time to design and build a new home can vary greatly, and there are a lot of factors that come into play. It’s important to remember that although you may think your Quonset hut home will be small and simple, and thus it shouldn’t take more than a few weeks or months to design and build, it is still a custom home that you are undertaking to build, and a custom home of any size is no small undertaking. Design and construction of a good custom home takes time.

Quonset Home Design Process

I always start the design process by creating a 3D model of the design, showing the arch panels in their exact size and shape, which allows me to model literally every component in the building to accurate scale. It is crucial to understand the exact three-dimensional geometry of the curve of your hut in order to create an overall composition of spaces that is both beautiful and functional, not to mention in order to get the technical details right. Once we have the essentials of the design worked out in the 3D model, we refine the plans, sections, and elevations as 2D drawings. Lastly, as we refine the drawings still further, we create the technical construction details. Clients often want to revise and change things as we go, which is totally appropriate to the task at hand, but also requires additional time and effort.

I meet frequently with my clients throughout the design process. The best ideas never spring fully formed onto the page; the best ideas require a process of refinement. In fact, the simpler and more elegant the design solution, the greater amount of refinement and editing it required to get there.

Quonset Hut Home Construction

Once designed, the project moves to construction. It’s important to remember that the construction of even a small, simple custom home still requires all the various subcontracted trades to show up, in the proper sequence, to do their job, however minimal it might be. All these companies have many other projects competing for time in their schedule. Since certain things have to happen in a specific sequence in order to build a home, it is challenging at best to try to get a construction project to go quickly. Various phases of the project require inspections as well, which takes time and can cause delay. Some components will have to be special ordered, which again takes time. All of this coordination, scheduling, and ordering takes time whether it’s a smaller job or a larger job.

You should not expect this to be a fast process, just because you perceive your small, simple custom home build to be, well, small and simple.

Bottom line: the design process is often 6-9 months; building permits can add 3-6 months depending on the jurisdiction, although this can vary greatly also. Construction can take anywhere from 6 months (extremely fast) to a year (more common) or longer.

Do you sell Quonset hut kits? Can I get a quote from you on a building?

No, I do not sell Quonset huts — I am strictly a designer. I suggest you contact SteelMaster USA for a quote on your building. Tell them I sent you!

Do you do construction? Can you build my project for me?

Many readers have seen my blog posts about our ongoing Quonset construction at the Quompound, and written to ask me if I can build their project for them. In short, no, I am not a contractor and I do not build the Quonset homes that I design for my clients.

I have extensive construction background and was a licensed general contractor, along with being a licensed architect, when we lived in California. When we left California and moved to Arizona, I relinquished my general contractor’s license, but have kept up my architect’s license. I believe my construction background (especially my own experience building our Quonset huts at the Quompound) makes me a more knowledgeable designer when it comes to the work I do for my clients, and I am grateful for that experience, but I have no intention to develop a construction business at this point.

I can, however, recommend two separate individuals with small crews who travel the U.S. erecting Quonset huts for people.They are:

Joshua Merrell: phone 731-220-5197
Danny Forbess: phone 641-521-4507

Both of these guys have been extremely helpful members of the Facebook Group, and many, many people in the group have said good things about both of them. From what I gather they are not what you would think of as “full service” general contractors, but rather that they both specialize in erecting just the Quonset hut. But, you should speak with each of them directly about what services they currently offer.