As my first design/build project, I was anxious about the task of actually assembling the timber frame and getting it off the ground. Typically a post and beam structure is assembled one of two ways: either with a crane, or a large group of people (the prototypical Amish barn raising). Due to lack both money for a crane and manpower for an Amish workforce, we decided to invent a third method; using a gin pole, scaffolding, a few pulleys, an automotive jack, and patience. But before the construction began, the task of surveying the site for the PV panels and demolition of the existing garage began.
The crew from 2K solar was very helpful throughout the process, establishing the height, angle and direction the carriage house’s roof had to be to maximize solar gain. They also offered labor on the installation of roofing to expedite the process, a great help on such a monotonous task.
We carefully disassembled the existing garage so we could reuse as much of it as possible. The siding was saved to be reused as flooring in the loft. The old cedar shingles were used as mulch around the property, and the beams went into the house’s wood stove for heat over the winter. The large star was saved to be incorporated into the new building.
We decided to use green lumber both to save on construction costs, and because as the wood cured it would naturally shrink, tightening up the joints as it did so.
The process was simple enough. After careful measurement each mortise was drilled, chiseled…
…and test fit. Because the wood was green the first bent we put together (above) actually warped in the front. Because of this the front of the carriage house bows out slightly. We learned our lesson after that and cut the mortises right before assembly instead of ahead of time, which stopped the issue.
Raising the first bent was a challenge. It took three tries before we developed a system of chocking the base on the foundation piers, jacking the bent up to about 20° , and then raising it with the gin pole. The first two attempts were particularly disheartening, as the bent would rise to about 60° vertical, then loose traction at the base and swing forward, crashing down at the base of the pole. Luckily the bent held together throughout this abuse, and we were able to establish a system to raise the rest without issue.
Once the first bent was braced in place, we were able to use scaffolding and pulleys to raise the girders and plates into place, bracing them with dimensional lumber.
The process continued for the remainder of the summer, expanding the structure bay by bay.
By early fall, we were ready to raise the last bent into place.
After going vertical, the bents still had to be moved into final position, requiring careful positioning and adjustment of all the beams that had to tie into it.
Here our good friend Bob demonstrates the fine touch needed to carefully assemble the frame.
Because we did not have a crane and were worried about the logistics of raising a typical timber frame bent with rafters, we decided to light frame the roof vs the typical rafter and purlin system.
To this end we raised a series of “mini-bents” to support the ridge beam as well as the end of the dormer roof.
Under a foreboding early winter sky, we prepared to lift the final two timbers into place.
Because the original purpose of the structure was to support PV panels, the roof was finished first to allow for their installation. We were under a time constraint at this point as winter could bring snow at any moment, but we could not delay installation until spring as the NY State tax credit for solar was due to expire by the end of the year.
The structure was buttoned up just in time for snow. At the last minute it was decided to add additional space to the first floor. Originally, the carriage house’s function as a garage was to be purely superficial; as a massive spruce tree, and an adjacent septic system precluded access from the street. This changed, however, when the homeowner realized that with careful trimming and moving of some gardens, a narrow driveway could be constructed to it. With a change in use, an ad hoc addition was constructed to allow for more room to store tools and garden equipment, as well as two cars. From the beginning an addition was always provisioned for on this side, however it was not expected to be added for several years.
All windows used were salvage. Those on the front and south facing side are historic casements from a local home, while those on the rear and north sides are modern salvage from a local company. The artificial slate shingles used on the addition were also left over from a reroofing of the main house a few years previous.
The large horse weathervane is one of only two in existence. The homeowner noticed it on a farmhouse in Bucks County (PA), and was told it was designed by a family member and made by a local metal worker. After further conversation, they were able to commission another to be made. It also functions as a lightning rod, protecting the structure as well as providing information about the wind. In addition, the strap hinges holding up the doors are also one-off’s also sourced from Amish country, by another blacksmith. The doors themselves are held together using wood pins and mortise and tenon construction.
The small windows for the second floor, as well as those in the garage door are leaded glass from a local antique shop the homeowner requested to be incorporated into the design. They are also working to source an antique dutch door for the main entry. In addition, the furthest right window was nixed during construction as it was decided a greenhouse would be added to this corner at a later date, rendering the window superfluous. The opening was framed out however, allowing for the original intent to be preserved, as well as provisioning for its installation should the need ever arise. The lighting in this photo also emphasizes the desired effect of the board and batten siding, throwing heavy shadow lines across the building.
While construction was not without its challenges, it was a rewarding experience in the end. Having only worked building light frame structures beforehand, the transition to heavy timber was incredible. The craftsmanship required to have tight fitting joints gave me a much greater appreciation for older homes and barns employing this method, as well as awe at some of the massive buildings that were able to be constructed this way. Developing a system of assembly was also invigorating, as while the task seemed daunting (and perhaps impossible) at first, by the end I felt a seasoned veteran at raising a timber frame. The experience of designing and building this carriage house has given me a deep appreciation for the system. I hope to employ it on more buildings going into the future, as the strength, resiliency and the incredible aesthetics of the form render it vastly superior to current methods. The actual cost of materials was not much more then light framing, and while we used hand chisels on our project, modern mortise machines can make quick work of the majority of the labor we incurred. The majority of the work was done by only two people, on weekends, over the course of a year. The integration of sustainable technologies was also exciting. The PV panels currently produce about 95% of the homeowners electricity usage. A future installation of solar hot water heaters will reduce the load on the electric hot water heater used now, which will enable them to produce more electricity then they consume. With its function as an auxiliary structure, it was decided to not insulate, but the deep cavities of the timber frame leads itself well to it. With only a small amount of supports, the effects of thermal bridging, frequent bane of those looking for increased performance in wood buildings, is negligible. If using SIPs instead of conventional sheathing, thermal bridging is all but eliminated. I look forward to incorporating the lessons learned from this project into my future designs. As a preservationist, using old methods to construct vernacular new buildings is highly exciting. The ease at which a timber frame adapts to modern sustainable technologies is also incredible, something I hope to take with me into both renovations and new construction.