Framing your Tiny House – Wood Studs, SIPs and Steel, Oh My!

When it comes down to framing your tiny house, there are generally three options (Minus cardboard – and yes, that’s a real thing – look it up!).

  1. Standard Wood Framing
  2. Structurally Insulated Panels (AKA – SIPs)
  3. Steel
  4. What should you choose? Each has their pro’s and con’s. Let’s check them out!

    Standard Wood Framing (2×4 stud construction)

    Pros:

    • People have been building with stud construction for countless years, so finding a qualified person to frame your tiny house will be easier than using any other method. Just make sure they’re familiar with residential codes! Having your entire house framed with some mistakes can be a disaster.
    • Stick framing is cheap. The cost of wood stud framing from Lowe’s or Home Depot will be significantly less in most cases than buying steel or SIPs.
    • This form of construction allows for a lot of adaptation and changes. You’re definitely not “stuck” with a layout or design plan once things get moving. Want an extra window? No problem! You can cut a few studs, add the appropriate headers, jack/king studs and cut out your window. The same applies with most changes.
    • No additional code approvals. This doesn’t necessarily apply to tiny house framing; but why not be as close to residential code as possible? After all, with issues surrounding approval in some jurisdictions for Tiny Homes, you want to ensure that whatever you have built for you will stand up against the local building code!
    • Problems can be fixed with relative “ease”. Standard wood framing has a lot of parts to it (studs, sheathing, etc.), meaning that if you ultimately have a problem that causes damage to your home, you won’t be replacing major components of your framing/walls/roof to resolve the issue. Let’s say, for example, that you have a problem with moisture coming through a window and leeching heavily into some wall sheathing. That’s OK! You can take out what’s damaged and replace it, and not have to replace major sections of an entire wall (which might affect your exterior, insulation AND interior!)

    Cons:

    • Stick framing is slow. Compared so SIPs or Steel framing (Although, with Steel framing it may depend on who your supplier is with regards to the time it will take to put together!) framing a wood stud home can be very time consuming. You have to measure and cut, measure and cut, measure and cut. You have to be sure you have appropriate blocking, spacing and placement to ensure that you can properly attach structural sheathing, etc. This sounds like a nightmare!!! Fortunately, we’ve mastered the art of Stick framing and can generally have an entire Tiny house wall framing complete in 1-2 days! (If you want to learn about how you can do this, you’ll have to attend one of our workshops!)
    • Some people will claim that Insulation is an issue here, and we will agree, and disagree at the same time. Firstly, wood DOES leech R-Value of insulation, however it’s absolutely not a conductor of heat/cold as steel is. Yes, you will lose some insulating benefits of a home by having wood studs, but there are ways to combat this. For instance, Huber engineering offers sheathing that has rigid foam insulation sandwiched between the stud and the sheathing. This essentially negates and R-Value loss from wood framing. Using spray-foam insulation will combat most of this anyway! Spray foam insulation is much more effective at keeping the heat in, the cold out, or vice-versa.
    • Stick framing isn’t straight! Yes, this is absolutely possible. If your builder (or you, if you are a DIY’er) isn’t careful, it’s possible to end up with a wall that isn’t straight. When you buy wood studs from your local supplier (Home Depot, Lowes or the local lumber yard) you’re likely to get some studs that have a higher than “normal” level of moisture inside them. As these studs dry, they may warp. This can cause real problems when framing your house. Also, compared to 10-15 years ago, most of the lumber you buy at the local big-box stores just isn’t up to par with the quality it used to be. You’ll undoubtedly find some studs in a bundle that you purchase that aren’t very straight. We suggest that you buy from a local big-box store (Lowe’s or Home Depot) and be picky with the wood you use! Make sure it’s dry, and if it isn’t straight, don’t use it! You can return it and get something else. When ordering your framing studs, account for an extra 15%. This will be good enough (generally) for waste and warped/bad studs.
    • Stick framing is heavy!!! Yes, it’s heavier than the option of Steel, and this can lead to repercussions. For instance, you may need a heavier-duty trailer. This is an extra expense. You may need a truck with a heavier towing capacity, this can be an extra expense.
    • Structurally Insulated Panels (AKA SIPs)

      Pros:

      • SIP construction is fast. If you have a builder who’s familiar with SIP construction, they can generally get your tiny house assembled in as little as a day!
      • SIPs are air-tight. With minimal places for air to leech through the walls, SIP construction can be extremely air-tight, which will ultimately aid in reducing your costs to heat or cool your home.
      • SIPs have great insulation value….SOMETIMES. If you get SIPs with Polyurethane foam sandwiched in-between the wood panels, then you’ll see a R-Value of roughly 7 per inch. Other types of foam (Expanded Polystrene), for example, can have a surprisingly low R-Value of only 3.5 per inch – which with a 3.5 inch SIP panel, is only an R-Value of 12.25 – lower than you’d get with standard R-13 roll insulation you can buy off the shelf at Home Depot/Lowes! The benefit however, even with a lower R-Value is that you will get less thermal bridging, since the dimensional lumber that you use will be far less than used with standard wood framing construction.
      • SIPS will save you money over time. Because you have SIPs, you will use less to heat or cool your home over standard wood framing. While it may take many years to see the benefit of this, eventually you’ll see that you have used less resources to maintain a comfortable living space for yourself with using SIP frame construction over wood frame construction.
      • SIPs are super strong. Because of the bonding strength of SIP panels wood to foam, you’ll find superior racking & shear wall strength with SIP construction.
      • SIPs resist mold and insects. This is true of most structures that use Spray Foam (which is what’s generally found in the SIP panel!). Mold can lead to costly repairs, as well as health problems, so this is a big benefit! This does however only apply to the foam, and not the wood of the panels. These things can get moldy, so ensure that you’re home is built correctly!

      Cons:

      • SIPs are strange! There are a lot of builders that don’t know how to work with or install SIPs! Make sure that you are getting a builder with the experience necessary to make your project go smoothly!
      • SIPs require a lot of attention. SIP Panels require that you pay very close attention to seams and gaps. If you do not get the proper seals and gaps filled once you have assembled your SIP panels, you may ultimately have issues with these panels. Give each SIP panel installation (especially at the roof) the attention it needs to ensure a quality, complete installation
      • Some SIPs… Suck. Not all Structurally insulated panels are manufactured equally. Make sure that you, or your builder, are buying QUALITY panels from a reputable manufacturer! Buyer beware here!
      • SIPS don’t allow for a lot of flexibility or change. Although possible, modifications to an initial project and/or layout can be very costly to you. Be aware that some changes (window or door layout, for example) may require you to order new SIP panels from your manufacturer and delay your build time. Make sure if you’re using SIPs to build your Tiny Home, that you’ve made your final decisions prior to you (or your builder) ordering your panels.
      • SIPs require a lot of planning! Because you are limited in flexibility and changes, you need to ensure that you have done all of your planning (and we mean ALL of your planning!) up front. Remember that this planning doesn’t just include the layout of your windows and doors, but for electrical as well. Most SIP manufacturers will have a channel set for you to run your electrical, so make sure this is planned will in advance!
      • SIPs may require extra ventilation. Because of how air-tight your tiny home may be with SIP construction, you may need to install additional ventilation or air-exchange systems. These can be costly! Some HRVs (Heat Return Vents) can cost you as much as $1000.00!! You can bypass some of this by opening a window. But keep in mind that sometimes the weather outside may prevent you from doing this as often as you may need to!
      • SIP Fixes can be a total nightmare (By total nightmare, we mean…… total nightmare!). If you have a moisture problem on your roof, for example, that has ruined your SIP panel; you may find that you’re not only replacing an entire panel, but also that section of the roof and interior (and maybe even electrical or plumbing depending on your design/layout). This can be a very significant cost to you, and may take weeks to fix!
      • SIPs can take a long time to order. Some manufacturers of SIP panels can be 10-12 weeks out from building and delivering your SIP panels. Be aware of this when you’re looking into your build schedule and plan accordingly!

      Steel Framing

      Pros:

      • Steel framing is light. Steel framing can be as much as 60% lighter than traditional wood framing. This can save you cost on a trailer that doesn’t need to have a heavy a load option, as well as giving you other options for types of vehicles to tow your tiny home.
      • Steel framing is straight. Traditional stick framing can have pieces of wood that warp or are not straight. Steel framing is generally straight (and will remain straight) allowing for a more consistent build.
      • Steel framing is strong…. If you use the right stuff! The stuff you buy at Home Depot/Lowes isn’t the right kind of steel to build a tiny home. That steel/aluminum isn’t as strong as necessary. But, the kind of steel framing we build with is an extremely strong, light gauge steel.
      • Steel framing is green. In many cases, steel framing can be recycled or is made from recycled materials.
      • Steel framing is fire resistant. This is pretty self-explanatory! Wood burns a lot better than steel!

      Cons:

      • Steel framing is new to some builders. Not all builders are familiar with the steps involved to build a tiny home with steel framing.
      • Steel framing can’t be changed easily. When getting your tiny house framed with steel, it will require that you provide engineered drawings to the steel manufacturer. This means that you’re generally “set-in-stone” with your design and layout of walls and windows. So, try to pick a flexible layout or at least be very certain with your layout before ordering steel framing!
      • Steel is as NOT energy efficient. Steel is a conductor of heat and cold – not an insulator. You can mitigate this to some degree by using great spray foam insulation, and insuring that you get the foam into the channels and right into all nooks & crannies!
      • Steel is expensive. Steel can be 2-3 times more expensive than wood framing. In some cases, your labor costs can be less, but Steel materials are significantly more expensive than wood stud framing.

      So, what do we like to use?

      Our base tiny house shell, and other builds are wood frame construction. But that doesn’t mean we don’t do Steel or SIPs. Sometimes a customer will request one or the other, or sometimes we can find a reason to shift to a different building method.

      How do you feel about wood framing, SIPs or Steel framing?

      What have you used in your tiny home build and what was your experience?

  • Taluh

    What is the lightest material? Thank you!