Thoughts from “getting started” to “what I learned”

posted in: Uncategorized | 0

(An edited version of this appeared on Tiny House Blog in December 2012)

IMG_0282I recently completed a tiny house for my personal residence in Asheville, North Carolina, and wanted to share a description, a few pictures and a video of it with other tiny house enthusiasts. I include a lot of detail to help others learn from my thought processes.

I’ve wanted to build my own house since childhood, and became fascinated with tiny houses upon discovering Lester Walker’s book Tiny, Tiny Houses in the late 1980’s. At the time I owned a small, post-war house in Austin, Texas, and it always felt so huge and inefficient. The rest of life distracted me for a long time, all the while I constantly dreamed about, researched and drew tiny houses for fun. After leaving a toxic job and traveling for awhile, I decided it was time to follow this life goal and build my little house.

I chose to build a fixed house, rather than a trailer-based dwelling, for several reasons:

  • I’m an urbanite and I’d rather live in town so I can walk or ride a bicycle to get places than drive a car very far. But it’s pretty hilly here in Asheville and harder to find an in-town backyard into which you can physically move a tiny house on a trailer.
  • I didn’t want to worry about getting caught violating housing codes by living in what the local governments would consider a recreation vehicle.
  • I didn’t want to own, or need to rent or borrow, a large truck each time I needed to move a trailer-based house.
  • A fixed house provides equity, potential rental income and better resale value.
  • I wanted the creature comforts of a large shower and full-size range.
  • I wanted outdoor rooms with more permanent features, such as a porch and a patio with landscaping and a garden.
  • The rebel in me wanted to push the bounds of how small of a house the building codes would allow, and I enjoy learning the associated complexities.
I started the design process by really thinking about how I live my life, such as:
  • how I use and share space
  • how much time I spend indoors and outsideIMG_1297
  • what makes a space comfortable
    • room size and dimensions
    • room height
    • window and door locations
    • furniture placement
    • traffic patterns and elbow room
  • what features are important
    • how much I want to cook
    • shower versus bathtub
  • what are my needs versus my wants versus society’s expectations.
In conjunction, I researched the size constraints and other relevant factors in the local and state building codes:
  • The City of Asheville, for example, requires that:
    • “Every dwelling shall contain at least 150 square feet of floor space for the first occupant thereof and at least 100 additional square feet of floor area per additional occupant.” That’s pretty small by conventional standards.
  • The State of North Carolina specifies, among other requirements, that:
    • “Every dwelling unit shall have at least one habitable room that shall have not less than 120 square feet of gross floor area.”
    • “Habitable rooms shall not be less than 7 feet in any horizontal dimension”, except kitchens.
    • “Each dwelling unit shall be provided with a kitchen area and every kitchen area shall be provided with a sink.”
    • “Every kitchen shall have not less than 50 square feet of gross floor area.”
    • “Every dwelling unit shall be provided with a water closet, lavatory, and a bathtub or shower.” Yes, two sinks; one in the kitchen, one in the bathroom.
With this basic information, I played around with building shapes and dimensions to create a layout:IMG_1292
  • For simplicity of construction, I chose a rectangular footprint.
  • I also chose separate rooms for the “one habitable room” and the “kitchen area”.
  • Then, I included a bathroom with a large (36” x 48”) shower pan and enough space to dry off without bumping into the lavatory and toilet.
  • I wanted to include a vaulted ceiling with a small loft at one end of the building.
  • For simplicity, I made the kitchen and bathroom the same length which allowed the interior wall to provide support for smaller ceiling framing and create a little more headroom in the loft.

The result was a layout 12 feet wide by 20 feet long with 10 feet high walls and a steep roof (14 vertical to 12 horizontal pitch). This created a gross footprint of 240 square feet and a gross loft area of 100 feet, part of which became a closet.A legally permitted house in Asheville could be smaller than mine. Another tiny house was built in town last year with a 12 feet wide by 18 feet long (216 square feet) footprint. A design might even approach the city’s 150 square feet minimum limit by interpreting the code language to allow the “kitchen area” to be part of the “one habitable room” (and receiving concurrence from the permitting officials).

Next, I thought about how site constraints affected the construction methods with respect to the building performance goals. For example, in performance, I wanted a very energy efficient building shell. But the site is a little challenging because it slopes up steeply from the street and the house is at the back corner of the lot. I considered structural insulated panels (SIPs), but the panels can each weigh several hundred pounds or more and installation would have required a very tall and expensive crane to lift them into place. IMG_0686I chose to use conventional “stick-built” construction with spray-foam insulation instead because I could hand-carry all building materials up the hill, construction was by standard methods, and the spray foam could be installed up to a couple of hundred feet from the contractor’s truck.

I tried to build as much of the house myself as possible. A friend and I hand-dug the crawlspace and footer trench, installed the reinforcing steel and poured the concrete for the footer. I hired a contractor to lay the concrete block foundation and I was his helper. I installed the foundation stucco. I hired a framer to help me erect the building shell and porch and a contractor to install the roof shingles (I didn’t want the risk of falling off and getting hurt). I installed the windows and doors, DSCN0036miscellaneous framing and exterior siding and trim myself, with a little help from a neighbor on some siding. I hired contractors to install the electrical and plumbing systems, spay-foam insulation and conventional interior drywall. I painted the whole building and installed the wood floor, shower tile, custom storage cubbies in the bathroom, kitchen cabinets and appliances, interior trim, patio stone, etcetera. Lastly, I contracted a local artisan welder to create a beautiful custom railing for the loft, including a latchable bi-fold gate and a hinged ladder that allows access to the electrical panel.

Some of the things I learned in the building process include:

  • When I submitted the permit application, the plan reviewer immediately informed me that any loft space accessed by a ladder could only be used as “storage” even though he anticipated it would be used to “store a bed”.
  • The plan reviewer also rejected my proposed use of a wood-burning stove because code does not allow an open-combustion device in a sleeping room and my design only had one habitable room which is, by default, the sleeping room.
  • Pouring concrete properly is very physical, very difficult and requires a lot of skill. I did a mediocre job, but next time I will hire a contractor.
  • The same wisdom applies to installing a concrete block foundation and stucco.
  • At the last minute during framing, I amended the permit to include a front bay large enough to sleep in and to give the building a more attractive face. My use of knee braces as an architectural feature to support the bay, rather than piers like those used for a deck, could not be approved “proscriptively” by the building code, so I was required to submit a design certified by a professional engineer or architect. As an engineer, I designed and certified it myself.
After living in the house for a few months, I’ve also learned (and confirmed) a few things about the design process:
  • Passive ventilation works better than I anticipated. An open window or two near the peak of the vaulted ceiling creates a nice breeze through lower windows in the other rooms and keeps the interior temperature noticeably cooler than outside.
  • Passive solar gain works nicely too. I don’t get so much sun that the house overheats, but on a chilly day I can keep the loft window open and crack a lower window for fresh air flow.
  • Spray-foam insulation make a very tight and energy efficient building shell. But the key is that the foam virtually eliminates air leaks, which is significantly more important than the R-value of the foam which is about the same as conventional fiberglass insulation. We’ve already had some cold weather in Asheville this fall, with a few nights around freezing, and the house heats very easily.
On the whole, the design and construction process was really fun, albeit physically demanding and included a number of head-scratching, problem-solving situations.