Building a Non-Toxic Tiny House: Some Considerations

Some preliminary considerations if building a tiny home with all natural materials:

1. Choosing Plans

my house
There are not a lot of companies selling technical drawings for non-toxic tiny homes. I only know of one: Tiny Green Cabins. Because I wanted a more modern style, I bought conventional plans from Leaf House. I wanted to change the layout to make the living room bigger, which entailed changing almost every other aspect of the design. In a tiny house, one change in the floor plans can change everything. This ends up costing a lot more not just in time spent redrawing plans, but in recalculating all the supplies: lumber, the electrical system, the plumbing system, (custom) window sizes etc. A lot of time (months) was spent calculating and ordering supplies. A week was probably spent on window placement and sizes alone. In order to reduce costs, you might want to start with pre-fab window sizes (or salvaged windows) and design around that. But it's way more efficient cost-wise to buy plans that are almost exactly how you want things to look.

the floor plan for my house
Just the change over to non-toxic materials  demands the following: changes to the framing in the flooring, changes to the thickness of the walls, ceiling, and floors (since insulation will be thicker), and changes to the weight. Not to mention non-toxic materials are generally twice the cost of conventional! You will also need to recalculate quantities of materials if using conventional plans, as you change from plywood to MgO board, and from foam (or SIPs), to cotton or wool insulation.



2. A Builder who Understands Chemical Sensitivities

I can't even imagine building with someone who did not have experience with natural building as well as a complete buy-in to the idea. Some tiny house builders I recommend are Jim from Tiny Green Cabins (MN, USA), and Safeshelters (CA, USA).Though many people now are choosing to go with someone local or someone very skilled. If they are open to the idea of green building and having you choose every material I would prefer a skilled builder over a "green buider".

3. Trailer Weight

the beginning of my house
A big SNAFU was that the plans we bought were designed for a trailer rated at 10,000 lbs, but when you switch from conventional to natural materials you may add a lot of weight. MgO board is much heavier that drywall and plywood; MgO siding or HardiePlank is heavier than wood siding; cotton and wool are heavier than foam insulation; and tiles or hardwood are heavier than vinyl or laminate flooring. A composting toilet is also fairly heavy.



4. Metal v. Wood

my poplar frame, should have used
cedar or maple
Metal versus wood framing is a really important consideration. To oversimplify the issue, metal framing involves using a thermal break of either foam or bubble wrap. It gets a bit more complicated than that, but this discussion by Tiny Green Cabins should help. Another possibility is to build the walls out of metal. For someone who cannot tolerate wood or MgO board this is an interesting new option. Check out this post to learn more about that. Consider that having metal walls, including foil inside your walls can aggravate EMF issues and causes a lot of difficulties with moisture management.




5. Mobile Home v. Travel Trailer Registration

MgO walls going in
This was one of the most confusing aspects of the build. Regulations vary from Province to Province and I'm assuming from State to State as well. In BC to get your house registered as a mobile home you have to have it built by a certified mobile home builder. Now, how exactly you get certified is not something you can easily find out, and multiple calls to government offices only resulted in completely different accounts, most of it wrong information. I am assuming that it is only large companies that can afford this paperwork and fees which means you are not going to be able to build a non-toxic mobile home in BC - which is ridiculous. If you can find the work around here please let me know, and this is something we all need to work to change. Not getting mobile home certification means not being able to park and live at a mobile home park which is unfortunate.

You can easily get certified as a travel trailer in BC (Ubuilt Travel Trailer is the specific designation) and this will also cause a lot of confusion at ICBC). You must find out the requirement before building, though there are not many requirements, i.e. one is the height, and another is a light on the back. There is an inspection sheet that is filled out at a mechanic that is certified to do this. Please make sure you do get the checklist for travel trailer before you build. It does have to be able to be moved so there are requirements for having it on the road. Then you take that sheet to ICBC and hope that someone there figures it out (took me 5 trips to ICBC in total). You can then get house insurance as a mobile home or as a travel trailer.

The requirements for a mobile home are much more thorough (if you are a mobile home certified builder) and must be contemplated before building. For example, with travel trailer certification, there was no requirement about grey water and black water tanks (and it turned out we did not need those tanks at all). No rules about composting toilets. There is a silver seal electrical inspection that you can choose to do if you plan on parking it somewhere legal.

If you are having someone in the US build it get them the checklist for your province though it will likely be the same as the requirements in the US. You can import a travel trailer which is a bit of paperwork and might involve you going down to the border to do the paperwork.

6. Choosing Materials

Poplar wood on the interior too (should have used maple)
It's hard to overestimate the time it takes - not just to re-draw plans to accommodate chemical-free materials - but to source and order those materials. I think we spent two months sourcing just the basic materials. You will have to do the leg work here as it's not possible to generalize where to procure non-toxic materials in every area. Every area will have a different supplier for MgO board, lumber, natural insulation, and the list goes on.

Factor in another couple of months to order samples and test materials for your own sensitivities. If you get sick easily, this will be a long and protracted stage as you find out what you can't tolerate by getting sick over and over. There needs to be time for recovery between testing. Definitely err on the side of caution as your sensitivities will increase once in a clean environment. It was a happy mistake that the finishing was left to me after delivery. the testing of wood stains/sealers/paints/tiles/tile sealers/shower materials has been a very long process and it has been much easier to do this slowly over time. Materials that I didn't react to when testing but now do include: cotton batt insulation (if you react to new clothing you will react to that), MgO board (I am on the fence about it - a few extremely sensitive people have said there is a slight reaction to it) and I have become much more sensitive to all paints and wood glues.

7. Time to Offgass
the view from my kitchen
Many materials and appliances will need to offgas before use. I didn't do that well in my house for the first couple months so I would say even with the best materials there is wiring, there is plumbing and plumbing glue, there is wood glue, there will be some silicone in the walls - these all need some time to offgas. We left the appliances running for a month before use.

I was lucky that I could move in immediately and left the window open for the first few weeks. Some people need a year to offgas a new house, even when every material was carefully selected.



Separate posts on tiny house systemscomposting toilet and grey water, custom non-toxic shower...

SaveSave

10 comments:

  1. Great post! So is it all offgassed and safe now?

    ReplyDelete
    Replies
    1. yeah after 2 months it was fine

      Delete
    2. Do you know anything about Rolux insulation? Supposedly used for hospitals and babies. It sounded really good until I dug deeper and they use 8% formaldehyde in the adhesives, BUT of course they claim they bake it out so there is no offgassing. Who knows? It's such a game. I'm doing some small projects and thought I'd try the denim insulation on part and the Rolux on the other. The denim sounds like it's too thin to be helpful, and your issues with the offgassing is a concern.

      Delete
    3. Sorry for my dyslexia - Roxul is the brand.

      Delete
    4. denim is preferable over roxul, wool is better. i have updated the post on insulation with all the latest

      Delete
  2. Hello We build tiny homes and would love to have a chem free home to offer ppl!
    please contact us at turtleislandtinyhomes@gmail.com

    thanks M

    ReplyDelete
  3. I want to build a toxin free home in the future, but I don't want a tiny house. Has anyone heard of any options for toxin free normal sized house builders and architects?

    ReplyDelete
    Replies
    1. There are builders that specialize in eco building. Check for one in your area.

      Delete
  4. I am looking for some land on which to olace my 1975 viking mobile home. It has outgassed. I live in an hoa ib san marcos,ca. My lot has a great view, etc. Just want to be on my own land. I can have this transported and finish working on it. Thank you for this information and all of your efforts.

    ReplyDelete
  5. I am looking for some land on which to olace my 1975 viking mobile home. It has outgassed. I live in an hoa ib san marcos,ca. My lot has a great view, etc. Just want to be on my own land. I can have this transported and finish working on it. Thank you for this information and all of your efforts.

    ReplyDelete