Do 3.5 inches matter?

It’s been a few weeks, and my trailer has arrived.  It’s of course taken longer than expected, with truck repairs and holidays getting in the way of prompt initiation of work.   I ended up opting for a design used by another tiny home builder who had purchased a trailer from the same dealer.   (By the way, not only does my sister know my tiny home compatriot and trailer designer, Colin, but he also built his house at another friend’s shop.  Very helpful guy) 

I wasn’t exactly sure how it would turn out, and hoped for the best.  It’s sturdy and clean looking.  The drop axles may make it hard to take the trailer over big bumps, but lower the bed by about 4 inches, which will allow me to sit up in my loft bed.  Otherwise, it’s a pretty standard flatbed with extensions on the side.  

tada!

My friends at Vital Systems Natural Building & Design are generously letting me occupy a covered space in their yard for the duration of the build, so here's the trailer at the shop, loaded down with materials for the framing and sheathing.   I can't thank them enough for a roof over my head, with electricity to boot.  Makes my life a lot easier.

But the question at hand (Do 3.5 inches matter?) really comes down to the age-old battle between the simple, affordable, and lean options, or complex, more time consuming/expensive, but potentially improved options.   My three constraints are weight, size, and budget, all of which leave room for a great deal of creativity.  

Since I know about 20 builders and plumbers and electricians, added to the natural building guys, everyone, including my cousins, is now giving me great additional design ideas, better material suggestions, and more storage space options.  All of which entail more $$ and/or time, but could really add to the functionality of the home.   The question of the week is, do 3.5 inches in floor height and about 10 fewer joists make a big difference in the long run?  The max height of the house is 13.5 feet, so every inch in floor height takes an inch away from the loft head room.  Every extra piece of wood adds to the total weight of the house, also a limited resource.

Here’s the logistics:  I laid out a sub floor to support my joists for the real floor on top of the trailer ribs (see picture below).  The only reason to add a floor above the current trailer bed is to make room for floor insulation.  This is actually important to do, even in the milder climes of the California Coast Range.

HOWEVER, as Tony from Vital Systems pointed out, there’s room under those flat boards to create a sub floor cavity for insulation.   The draw back:  complex, and could take me a few days to work it out, and includes a lot more drilling into the frame.  The benefit:  I get 3.5 more inches in height to play with, and the trailer’s a bit lighter.  Not much, but some.

After bolting down the “sub floor” to the angle iron, I’m not so excited about putting 50 more holes in even thicker steel of the trailer frame.  Framing out the floor on top of the trailer bed would take me a day.  The other option, who knows, with all the special cuts and crawling around under the trailer.  Then there's the plumbing to think about.  Would there still be room for it?  ARGH, decisions.