Sustainability Matters

Why sustainable?

Why anything else?!?

A definition of sustainability - "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." from "Our Common Future," United Nations, 1987.

In what way is the Cubit sustainable?

Small Physical Footprint
-temporarily permanent installation: requires no permanent foundation, no septic tie-in, no grid connection, no fixed well
-easy to heat: small square footage and energy-efficient envelope translates to low BTU requirement.

Energy Efficient Envelope
-consists of SIP walls (R-24 roof, walls & floor) & low-emissivity argon-filled double pane insulated glass

Natural & Simple systems
-photovoltaic solar electricity: 12-volt electrical system is designed to run lights, charge laptops, cell phones and audio equipment, and run a few electrical appliances
-rainwater catchment: directly taps an otherwise unused source of water
-passive solar heat: south-facing windows utilize solar heat gain in the winter
-natural ventilation: windows are designed to catch and direct breezes for natural cooling in summertime
-natural daylighting - natural light is utilized to reduce lighting load
-compost toilet & greywater system: low-impact systems to manage human waste, and turn the waste into a useful product (compost and irrigation for a garden)

Sustainable Materials
-salvaged lumber used for windows and doors
-siding and trim was locally harvested & milled lumber
-EPS SIPs - waste product (saved from the dumpster) recyclable, durable - SIPs provide efficient insulation with minimal thermal breaks

Cubit Construction

The foundation of the Cubit is a steel trailer. This allows the house to be moved when necessary, and also helps to lessen the ecological footprint of the house by not requiring a permanent foundation.


The panels were hauled on the trailer across Vermont to the construction site.



The floor was built upside-down on the trailer and then flipped over. It required lots of levers and rigging - next time, I will build the floor right-side up!


SIP walls are precut, according to shop drawings, and then framing lumber is added afterwards.

The SIP walls are pre-built on the platform, and framing lumber is installed and screwed in place.

Once the walls were built on the deck, they were then raised (with help from my father and Herb Bates) and secured in place. Firefly, my dog, was also very helpful with the construction.


The roof panels were hoisted onto the walls using ramps and straps.



After the walls are assembled, foam is injected into holes drilled in the panels. This helps to seal the envelope of the building, and create a continuous insulation barrier.


The walls are wrapped in tar paper in order to help weather-proof the walls.


Siding is applied over the tar paper. The siding is built out from the walls, with a 1/4" space behind it to allow for vapor venting and prevent rot.


The siding is secured with screws in order to strengthen its fastening to the walls for transport over the road. Everything must be designed to withstand 70 mph winds!

After the construction was complete, it was time to move the trailer - it was a trick getting it out of a tight space!

The Cubit trailer, secured and ready to haul!!!

Energy Efficient Doors and Windows: Design and Build

Windows and doors are an indispensable element to building a house. They provide ventilation, light, heat from sunlight, and a means to enter and exit a space. They also function to protect the interior space from the outside elements. In order for doors and windows to be energy-efficient, they must create a tight seal at their edges and insulate from the cold, as well as functioning (opening and closing) to provide ventilation.

Designing windows and doors and building them from scratch was the most challenging aspect of this project. Not only did I have to design a window design which seals out the elements and provides optimum insulation and sunlight, but I also needed to acquire materials and design a shop process for milling the windows to precise tolerances needed to assure proper operation of the window unit.

Designing a full set of custom windows was too much of a task. If I did this project again, I would acquire salvaged windows, and then design my house around them!

The joinery for the window was was fun to design:

The window joinery took three tries to get right. Mock-ups of the joinery were important for me, in order to understand how the rails and stiles fit together. The window joint is a double-lap joint.

The joinery is pegged (square pegs in round holes) in order to make it stronger and more stable. The peg holes are offset in order to draw the joints tighter, so that clamps are not required for the assembly (I don't own enough clamps to clamp all of these windows!)

Here are the finished windows units, ready to be installed. The glass units are 3/4" double pane insulated glass, with low-emissivity coating.

The doors have a square mortise and tenon. The tenons are cut on a table saw and the mortises cut with a square-mortise machine (a drill press with a square bit). Precise milling of the wood is critical to ensure a consistent and tight fit for the joints.

Small-scale Manufacturing Processes

When I made my windows, in order to streamline the process for manufacturing 9 window units, I developed my processes to be easily repeatable. The window sashes required multiple passes on the planer, and multiple passes through the table saw: first to cut the profile of the sash, and then to cut the joints at the corners. Each precision setup on the table saw would be run however many times were needed (sometimes up to 36 times) before breaking down the setup and making a new setup. Special jigs had to be made, which attached to the table saw, in order to keep the operations precise.

Jigs are important; when the same cut must be made tens or hundreds of times, making a jig saves a tremendous amount of time, saving the measure, cut, measure, cut process. I applied this principle a number of times: cutting the siding (every piece cut to 72 1/4" inches), manufacturing the trim (every one had to have the same lap cut in it), milling the windows, and cutting the joinery for the doors.

Recycled & waste materials

When milling the features of my house, I used reclaimed materials whenever possible.

The doors are milled from 220 year old lumber: hard pine floor joists which came out of a 1790's cape which was disassembled and moved. The timber was harvested on the present site of Timberlee Park, my childhood home (a 1970's neighborhood development), and was milled at the Cooperage, a local sawmill.

The window sashes are milled out of wall studs which came from my brother's 1948 home. The studs were beautiful, clear, straight-grained douglas fir with 20 growth rings per inch. These framing studs, which today would be grown from fast-growing spruce, were harvested in a time when old-growth forests were more abundant. One would be hard-pressed to find wood this nice in a lumberyard today, even at a steep price.

The jambs of the windows are made from reclaimed waste wood: timber cut-offs from a timber-frame jobsite.

The walls are built from scraps of SIPs (structural insulated panels) which I salvaged from a SIP manufacturer's yard. The scraps were bound for the dumpster, and by building my house out of them, I was giving them a second chance at life.

Moved my tiny house!

Yesterday, I hauled cubit over the mountain. 150 miles, from Ashby, MA to Saratoga Springs, NY. The move went well, and incident-free (we did crack a taillight bottoming out at the end of the driveway).


The house is now situated at Empire State College at 111 West Avenue in Saratoga Springs, where it will be on display until December 13, 2010.

Interior pics, as of tonight

Progress has been getting in the way

It has been months since I have updated these pages, mostly because I have been too busy building my tiny house!

The windows have been built and installed - hoo boy what a project!!! I am quite pleased with the results though. More on that later...

The exterior trim was next, and also a very challenging project (still yet incomplete) full of tiny details - never would I choose to do things the easy way.

This picture is a week old:



The loft has been in place for some time, but I have started with interior furnishings, which is making it feel like a house - it is interesting dwelling within the space, getting a feel for it.

I am frantically preparing for my exhibition at Empire State College, which goes up November 13. (yikes!)

I will update this blog further soon. I promise.

Raising the Walls

I have raised the east and south walls of my house! I had some help in the raising from my dad and from Herb Bates. It took days for me to cut, fabricate and build walls and to prepare for raising. When it finally came time to raise the walls, though, it happened in a matter of minutes, and then we were standing in the space of a structure!

I will post a video of the raising soon, but here is a photo:

Building the Walls

I'm building walls today. Over the past week, I have cut & routed them, and yesterday and today I am assembling them with all of the structural lumber - this is the time-consuming part.





These are the box-posts and box header for the south wall. Each one took about an hour to assemble. They will be filled with foam after they are installed. Also note the box of Cheez-it for lunch.





I am assembling the walls on the trailer floor. Shown is the east wall (the most complicated wall) and the south wall on top (2 panels, and I will be adding 2 box posts and 1 box header).

After they are assembled, I will raise the two walls, and I will be able to stand inside my house!

Flipping the Floor

I built my 8x13 floor panel upside down, and had to flip it yesterday, by myself (in pouring rain).














It went well (the last 2 seconds were pretty exciting, but it landed where it was supposed to, with no damage to person or property).

Thank god for simple machines! Levers, ramps & pulleys. A 2x6 can be your friend!

Burning Styrofoam

I have been using the hot knife for the past couple days to fabricate the wall panels.

Burning EPS has a distinctive odor. It reminds me of the smell of Kathmandu in the evening; at the end of the business day, many shopkeepers kept a ritual where they would burn the trash from their day in the gutter. It's a nostalgic smell, that burning plastic aroma (especially when combined with the smell of cheap cigarettes that my crew-mates used to smoke on site). Ah, memories.

But actually, the burning foam, with its thick smoke and smell, made of pure petroleum-derived hydrocarbons, is composed of approximately the same elements as wood smoke: carbon, oxygen and hydrogen. Its smoke is less harmful than smoke from a pine fire.

Styrofoam may not seem to have much "green" cred, being a non-organic petroleum product, but it does have a couple things going for it:

It does create a super-efficient building envelope. My walls, when I'm done, will be as tight as a drum. Air leakage will be minimal, and the insulation value meets or exceeds requirements for such a tiny building. I expect that it won't be difficult to heat my tiny house.

Another benefit of EPS is that it is a durable use of petroleum. I drove to the worksite this morning burning a non-renewable resource (a situation I hope to remedy this summer when I start brewing bio-diesel from vegetable oil). Once petroleum is burnt, it's gone, and the carbon enters the atmosphere. My walls, on the other hand, utilize that same resource daily throughout the life of the building. As long as the walls are standing, the carbon that they are made of is, in the parlance of the green movement, "sequestered", meaning trapped, and providing me with a daily benefit.

Exploring the use of EPS foam in my building envelope is an interesting exercise in sustainability. The panels I am using are waste panels from an inefficient production process; I am saving them from becoming landfill or being incinerated in a waste-to-energy facility. The panels are a durable product which have a net benefit by saving energy over the course of their life-cycle. Large-scale usage of this product may or may not be ultimately sustainable, depending on the design of the manufacturing process. However, for my project, I feel pretty good about using SIPs, and I'm learning a lot in the process.

The sustainability of consuming petroleum products on the large scale that we do is highly questionable. Petroleum, though it is a non-renewable resource, is quite an amazing product. The versatile molecules can be cracked and recombined in a myriad of ways, resulting in an array of products that benefit us every day. Limited, judicious usage of petroleum products can be beneficial. Exploring sustainable alternative to petroleum such as biofuels and soy-based foam products is well worthwhile.

SIP Wall Mockup

Finally, I acquired a hot knife, and construction has resumed.

Here is the tool:








And here is the wall mockup I made with it:









This is an illustration of the corner where the walls & floor meet. Of particular interest is the box post at the corner, built from 2x material, and filled with expanding foam to reduce thermal bridging. Also shown is a surface spline joint, the method of joining two panels with OSB splines.






Here is a drawing showing the corner box post.

Hot Knife

I have this tool that is hanging my project up: a foam-cutting hot knife. I need it to progress to the next step of assembling my envelope. The tool consists of an electric heating element that creates enough heat to melt the EPS foam cores of the structural insulated panels, in order to create voids to insert framing lumber into the panels.

I could buy the tool, but that is $150 or $200 that I'd rather not spend for a single-use tool.

I have been foiled in two attempts to make such a tool: first, some unsuccesful trials with a torch-heated metal bar nixed the idea of a propane-heated element; second, I tried bending heating elements from an electric stove, with dubious results.

I think that I finally found a place that I can rent a hot knife: Winter Panel in Brattleboro VT. I'll be going through tomorrow, and I'll pick it up.

I'm chomping at the bit to get some structure up in the air, and to see this project start to take shape!!!

CUBIT

Could
U
Build
It
Tinier?

Cutting Panels

Now that my trailer is situated and the materials are unloaded, I have started to cut SIPs for the wall panels!

There are two specialized tools I need for cutting & prepping panels: a panel saw and a hot knife.

The panel saw is a pretty cool tool that I recently acquired. Wall panels are 6 1/2" thick, and the roof panels are 8 1/4". In order to make a cut this deep with a power saw, I need a different type of blade than a standard circular saw. Even the largest hand-held circular saws available, besides costing $700, can make only a 6 1/4" deep cut, leaving 2" of panel uncut on roof panels. Another option I thought about was cutting the OSB on one side, flipping the panel & cutting the OSB on the other side, leaving only 2" foam to cut with a handsaw. But an 8'x8' panel weighs about 225 lbs, so I would like to avoid as much as I can flipping the panels.

Enter the beam-cutting saw: This tool is half circular saw, half chainsaw. The top half is my old Makita circular saw (recently replaced with a new DeWalt circular saw). The blade of the saw is where the action is: it is a 12" chain bar attachment called a Prazi Beam Cutter, purchased online for $135, which is run by the circular saw head.




I fitted the saw with a dust collector shroud that attaches to my shop-vac and collects a lot of the little white styrofoam beads from the cut. The saw is working out great, and it's fun to use!

I am now trying to track down a 5 1/2" wide hot knife: this tool has a heating element that is used to melt the styrofoam cores of the panels, in order to create voids to install wood framing lumber into the panels as structurally required. This tool is available commercially for purchase for $180, but I've never done things the easy way - I am attempting to make one myself. I will post my progress on that endeavor...stay tuned!

Comin' Over the Mountain

I loaded my trailer full of SIPs in Bennington, VT. I figured the load of SIPs at about 3100 lbs, plus 875 lbs trailer weight: just under 2 tons. A small load by road standards, where a tandem semi-trailer might weigh up to 40 tons. Still, if a 2 ton load fell on you, you'd know it. So I treated the load with an appropriate dose of respect.

My friend Sue Bates has offered me a plot of land on which to park my trailer to build my tiny house. The building site is in Ashby, Massachusetts, a nice little spot behind Sue's barn, next to the garden. To get there, I need to haul my fully-loaded trailer 90 miles. We would travel VT Route 9, from Bennington up over Hogback Mountain to Brattleboro, and then into New Hampshire to Ashby. This stretch of road, full of twists and turns, up & down the Green Mountains, happens to be my all-time favorite road; I've driven probably 200 times in my life, and I haven't gotten sick of it yet. I never pulled a trailer over the mountains, though. I was looking forward to it!

Though my trusty diesel Jetta serves me well as a work-truck, this load is a little beyond what Sparky could handle. My father, Bob, kindly volunteered his Toyota Highlander for the job. Though he feigned reluctance at times, I know that he actually loves playing trucker (he does have reason to be a little gun-shy: he once blew up the transmission on a borrowed truck, driving a horse-trailer halfway across the country; I did everything I could to re-assure him that his Toyota could handle it). He drove over to Bennington to meet me in the yard of Timberline Panel Company, we secured the load with ratchet straps and pulled out onto the road, the Toyota Highlander, the loaded trailer, and Sparky as the chase car.


The load towed quite well going up the mountains. We passed our friends Fred & Roberta, headed the other way, on their way out to vacation. We pulled over to say hi and check the load. Our packing job worked well, and the load had not shifted at all. The trailer was handling its maiden voyage admirably!


We had good weather on the way up the mountain, but as we crested the Green Mountains at Hogback Mountain, the sky was darkening, and as we headed down the other side it began to rain. On the way down the mountain with the trailer pushing from behind, the load "wagged the dog" according to Dad, and gave a bit of a ride to the tow vehicle.

In Brattleboro, after driving through the rain for 30 miles, we decided to pull over in the Fire Department parking lot to tarp our load (of course, it promptly stopped raining). The underside of the load was dripping wet and dirty from road dirt. It made me sure that I would have to weather-proof the underside of Cubit.

The load made it all the way over the mountains with no mishaps. The next trick was to get the trailer into its yard, between the barn and the fencepost, which were about 8 1/2 feet apart (the trailer is 8'-1" wide).

After turning and backing and pulling forward and backing and turning about 28 times, and sinking into the soft soil of the flower bed, we decided to break open the load and hand-carry the panels into the yard (not my favorite choice, as some of the panels were upwards of 200 lbs). But that's what we did, with the help of Herbert Bates (it was a good thing that he happened to be there, otherwise we'd still be backing and pulling forward and backing again). Once we lightened the load, we were able to back the trailer into place. Who knew that after 90 uneventful miles, the last 150 feet would take the most work?

It was exciting to get the trailer to where it will be built, and the panels staged and ready for cutting! Here's a photo of the yard:


Now I have a bit of work prepping the yard and setting up tools, and then I start cutting the panels!

New Tools

On Thursday, I visited another former employer, Jon Harris. Years ago, I worked with Jon in his cabinet-making shop, and we became friends, so I like to drop in on him every now & again and see how things are going.

The last time I saw Jon was maybe 2 years ago, when I helped him to prop up a falling-down shed off the back of his barn. Inside the barn, Jon had a couple of tools sitting under a tarp, and we struck a deal where I bought the tools from him. I hadn't been by to see Jon in the past couple years in order to pick up the tools, but I gave him a call the other day, and sure enough, he said those tools were still sitting there in the barn.

There were two tools: one was a Delta drill press, which is a good tool, and will come in handy. The other, though, is the tool that I am really excited about: it is an Inca combination jointer/planer. It has the capability of squaring lumber and then planing it to finish thickness. This tool will be indispensible to the building of my windows, because I will be building the windows from reclaimed lumber. So when I get this tool working, I will be able to use it to mill all of my lumber to accurate size and squareness, so that I can then cut the precision joinery that will be required for my window sashes.


This is a photo of the Inca as it was loaded in the back seat of Sparky, my trusty little VW diesel Jetta, my "truck".

The Cubit's Trailer

I picked up the trailer, the foundation of my tiny house, on Wednesday.

The trailer was fabricated by Brian Nilsen, who has a metal fabrication shop in his 2-bay garage on a bend in the road between Cambridge and Greenwich, NY. I designed the trailer with Brian, and he & I figured out a lot of the details together: spacing of members, placement of wheels, required suspension clearance underneath the deck, etc... Brian was great to work with, very reasonably priced, a stand-up businessman & all-around good guy. He did a great job building this trailer. He was extremely helpful right up until I drove the trailer off his yard, and I'm sure that he will be a big help in the future, too, with any metal fabrication needs that come up for me.

The specs of the trailer are as follows:
Length: 19'-6"
Width: 8'-1"
Ball height: 16"
Deck Height: 22"
Axles: (2) @ 71" long
Unladen weight: 875 lb
Weight capacity (GVW): 4400 lb (1100 lb per tire x 4)


This is the drawing that I provided for Brian.

The finished road height of the overall structure will be around 13'-0", under the 13'-5" road height maximum.

It is a deck-over trailer; that is, the wheels are entirely underneath the deck, so there is no need for fenders to be built into the house. In fact, the whole double-axle undercarriage is easily removable: remove 6 bolts and it's free. I will salvage 4 jacks from the junkyard, one for each corner, so the whole structure may be lifted, the undercarriage removed, and the house dropped on 4 sono-tube footings, so the house is temporarily permanent (or is that permanently temporary?)

It was exciting to see the first full-size manifestation of my house. I stood on the empty trailer, and got an idea of what it will be like to stand in my tiny house.

I picked the trailer and hauled it to Bennington VT, where I dropped it off in the yard of my former employer, Vermont Timber Frames and Timberline Panel Company.

The manufacturing process of Timberline SIPs is a hydraulic press which creates 8'x24' Structural Insulated Panel. The large size of the SIPs helps speed installation of large surfaces such as industrial roofs. For smaller applications, however, such as SIP or timber frame homes, the 8'x24' panel can be difficult to use efficiently. Sometimes large pieces are cut off and left unused. They often re-sell these to consumers who are building smaller buildings at a discount rate. As a former employee of Timberline, I have been given the benefit of being able to use them to build my house, and thus save them from sitting in the yard as waste. So I will be hauling away enough to build my house with! Thank you Timberline!

SIP Shop Drawings

These are the shop drawings that I will use for cutting and framing the SIP walls. I will be building from waste SIPs, so I will be adding seams where I join smaller panels together.