Ordering My Tiny House SIPs

Iso Today I placed the order for my SIPs (structural insulated panels) with Patrick Sughrue of Structures Northwest. This means it’s time to schedule the wall-raising for my gypsy wagon. At this point it looks like it will be about three weeks out. Eeep! My tiny house build just got real!

floor plan of my gypsy wagon in SIPs

Ordering My Custom Vardo Trailer from Iron Eagle Trailers was a big step, but ordering my SIPs feels much more momentous to me. Patrick and I have been talking ever since we met at an open house at Caravan – The Tiny House Hotel last fall. At the time I was thinking about building my own SIPs, but Patrick convinced me it would be easier and more cost-effective to have them factory-built instead. So I spent the past few months noodling over them and it was pretty exciting to finally sign on the dotted line and write the check!

the front of my gypsy wagon - a cut out for my arched door

Patrick will be sending shop drawings for my review in the next couple days. Then my order will go to the factory where my panels will be manufactured to my exact specifications. When my wall panels arrive flat-packed they’ll already have the holes cut and the framing in place for my arched end walls, my wheelwells, My Arched Window, My Kitchen Windows, and My Beautiful Arched Door. In order to have them just right I double-checked all the measurements for my door and windows. I also had to have precise measurements from my trailer, so Laura and I paid an extra visit to Iron Eagle Trailers to take down measurements and check in with Rob. (By the way, if you let Rob know I sent you, he’ll give you $50 off your trailer order!)


Since it’s more difficult to modify SIPs in the field than it is to modify stick-built walls, I’ve made my final decisions about my window and door placement. It’s amazing to me how much I can dither over these choices, but I’m feeling pretty good about my decisions right now. My walls will be 8 feet tall instead of the 6 feet that is more common in vardos. I love the coziness of a short-walled vardo, but living in Sweet Pea, I’ve come to really appreciate the spaciousness of higher walls. Since the sheet goods come in 8-foot lengths it would create more waste if I chose shorter walls – and it wouldn’t cost any less. Going with 8-foot walls instead of 6-foot walls, I’m able to contain more space with less waste at the same cost. Seems like a good choice to me. I’ve centered the door and windows in their panels so my house will be symmetrical. I’ve enjoyed the process of designing my house both from the inside-out and the outside-in. I can’t wait to see how it feels to be inside the space!


SIPs are composed of two pieces of OSB (oriented strand board) glued to a piece of Styrofoam. Typically, I’m anti-Styrofoam. However, I believe that this is an appropriate use of the material. The very same things that make Styrofoam a lousy option for disposable packaging and single-use dishware make it great for a wall system – it takes approximately forever to biodegrade – which means it’s very durable. Additionally, it’s super lightweight (which is great for a mobile structure) and it has great insulation properties (which will reduce the long-term heating and cooling costs for my gypsy wagon). Yes, it has very high-embodied energy, and no, I probably wouldn’t use it for a ground-bound house (so many wonderful natural building options – like strawbale, which is like a natural version of a SIP!) However, I believe SIPs are an appropriate technology for tiny houses on wheels. The idea of using SIPs for a tiny house on wheels initially occurred to me four years ago, before I’d heard of anyone actually trying it. Now dozens of people have done it and I get to benefit from their pioneering efforts. (To read up on it, check out Jenna and Sean’s website Vagabode or their most recent post on TinyHomes.com To SIP or Not to SIP?)

the stern of my gypsy wagon (with a cut out for the arched window that started it all!

I’m so excited about my tiny house I’m not sure I’ll be able to sleep tonight! But I better because tomorrow is Earth Day and it’s going to be a big day. Dee’s book The Big Tiny comes out tomorrow and she’s in Washington, D.C. for the book release. There’s also a groundbreaking for the Breathe Building, a Living Building Challenge project I’ve been working on. So many great things to celebrate!

Besides, I need to get my rest because I have a lot of prep work to do in the next few weeks! Here are a few things on that list: Planing My Arched Rafters, Refinishing My Arched Door, Cleaning Up My Kitchen Windows, and Prepping My Skylights. Ready and go!

P.S. The other quote I got for SIPs was from Allen at Pacific Builders and I'm sure he would have done a great job, too. If I were building closer to their manufacturing facility in Montana, I probably would have picked them.