The Inner Envelope

I define the inner envelope of my tiny house as everything between the Zip panel (with its own vapor barrier) and the inner siding.

Walls: Total R Value 18

For rigidity of the structure, in the corners and key areas (about 20% of the entire structure) of my advanced framing, I placed a combo of 1 inch Owens Corning Foamular 250 (R Value 5)  and 2 inch Bonded Logic recycled cotton jean insulation (R value 8).  The last .5 inch is an air layer between the layer of stapled Ecofoil radiant barrier and my interior walls.

In all remaining walls I have 3.5 inch of Bonded Logic (R value 13) slightly pressed in with stapled Ecofoil and .5 inch airspace.

Dormer and Cathedral Ceiling: Total R Value 18

I have 3.5 inch of Bonded Logic (R value 13) slightly pressed in with stapled Ecofoil and .5 inch airspace.



Floor: Total R Value 33

Two layers of 1.5 inch Owens Corning (R Value 15), 3.5 inch Bonded Logic (R Value 13) and Ecofoil (R Value 5).


A Tiny House that Breathes?

Three years ago I was thinking about my future tiny house envelope and chose to incorporate biomimicry as much as I could. This traveling educational exhibit, traditionally designed, to educate others on sustainable lifestyles and building retrofits, rehabs and/or repurposed construction can still incorporate biomimetics in its product choices. My next tiny house will be far more organic in design, with eco-skins, almost imperceptible from its natural surroundings. But I digress.

Nature’s design as inspiration is not new (Sacred Geometry, Golden Mean, etc.). Biomimicry, Cradle to Cradle or LCA (life cycle analysis) concepts are basic inspiration for Smart Sustainable Design.

Deciding on a vented breathing roof and rain screened walls delayed my build a bit and it was well worth it. I began installing Benjamin Obdyke’s product, Homeslicker rainscreen in late Spring during a workshop I held for tiny house enthusiast’s, video below.

My siding applications were done in sections around the house over the summer.*

Later Rainscreen

Note in the middle picture that 3 inches of screen was folded around the edges to allow drainage but discourage insect infestation. More about how to install Homeslicker here.

Homeslicker is a nylon mesh matrix that comes in a 40″ x 46′ roll and has little vertical channels that direct rain flow down the walls surface. It is very easy to install (I’m not a builder) and provides about a 1/8″- 1/4″ air layer, when compressed, between my Zip panels and my metal or wood siding.

Homeslicker will protect your wall assembly from rot and mold, allow moisture to escape, a thermal break, and prevents damage from surfactants between your vapor and siding. A great solution for tiny housers!

*Check out a similar ventilated underlayment, CedarBreather, I installed on my roof here.

Article in Green Builder Media about the Silver Bullet: