Green Backyard Office: Repurposing a Century-Old Garage

Halifax, NS

Oct 20 2009 By Jennifer Corson | 0 comments

General Specs

Location: Halifax, NS
Living Space : 150 sqf

Architect: Jennifer Corson and Keith Robertson, Solterre Design
Builder: Michael Gorman and Martin Philbey

Site

  • Original driveway repurposed as garden beds
  • Dry-laid slate slabs create permeable patio
  • General Design and Construction

  • Existing shell of building left predominantly intact
  • Building Envelope

  • 4-in. IcyneneOpen-cell, low-density spray foam insulation that can be used in wall, floor, and roof assemblies. It has an R-value of about 3.6 per inch and a vapor permeability of about 10 perms at 5 inches thick. spray foam in walls and ceiling
  • 2-in. XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation. foam under concrete slab
  • Custom-built acrylic-sheet storm windows
  • HVAC

  • In-slab radiant heat connected to solar hot water collectors
  • Backup electric baseboard
  • Lighting

  • Natural daylightingUse of sunlight for daytime lighting needs. Daylighting strategies include solar orientation of windows as well as the use of skylights, clerestory windows, solar tubes, reflective surfaces, and interior glazing to allow light to move through a structure.
  • Interior Finishes

  • Locally sourced shiplap pine boards on walls
  • Exterior Finishes

  • Original unfinished cedar clapboards
  • Locally milled and salvaged materials and a focus on preservation and simplicity make this small remodel a big success

    When we purchased our circa-1896 farmhouse in 1994, one of the main attractions was the old garage. We quickly replaced its failing asphalt roof with new cedar shingles in 1995, but as much as we liked it, the garage remained a somewhat forgotten backdrop to our yard until we were forced to address structural issues in early 2008.

    Solve the big problems first
    The impetus of this project was a crumbling concrete slab and corresponding splayed walls. We jacked up the entire building to remove the rubble and form the new foundation. Luckily, the rest of the garage was in good enough shape to survive the jacking relatively intact. In fact, we hardly touched the cedar exterior—which likely had not seen paint for over 40 years—and left it unfinished.

    The initial approach was to “save” the garage. Once we had emptied it out in preparation for the renovation, we realized that it was just a place to store nothing of value. At the same time, we were outgrowing our architecture firm’s office around the corner, so this seemed like a perfect opportunity to solve more than one problem. We purchased a small garden tool bin to store the push-reel mower, rakes, and shovels, gave the rest of the contents to the recycling depot, donation shops, and neighbors, and began planning our new workspace.

    Design Approach: Sweat the Details, But Keep It Simple
    At Solterre Design, we enjoy getting into the details of a project but are generally minimalists. The original simplicity of the small garage and our conservation-minded design philosophy guided many of our decisions. With salvaged doors and windows, locally milled pine boards, and an acid-etched concrete slab, most of the new interior finishes are merely refinements of the original interior surfaces. The only modern details that stand out are the smooth plywood ceiling panels and the rich color of the dyed floor.

    Comfort Without Much Effort
    We had to decide whether or not to insulate the new slab. Comfort was a key concern, so we placed 2 in. of XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation. under the new concrete and installed radiant heat tubing; these will soon be fed by a pair of flat-plate solar collectors that have been knocking around our architectural salvage company, Renovator’s Resource. There will be no heat storage tank, just the volume of the collectors and the tubing in the slab; a simple, 50W, PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.-powered pump will circulate a glycol solution through the system. An electric baseboard will provide backup heat until we have the solar hydronic system worked out, and it will also pick up the slack in colder months when solar isn't enough.

    To help keep the heat in, we sprayed IcyneneOpen-cell, low-density spray foam insulation that can be used in wall, floor, and roof assemblies. It has an R-value of about 3.6 per inch and a vapor permeability of about 10 perms at 5 inches thick. between all of the rough-sawn 2x4 studs and rafters. We painted on a latex vapor retarder before applying the finish boards and plywood. The 24-in. spacing of the old framing was a good fit with the 4-ft. sheets of plywood we chose for the ceiling, requiring little cutting or additional blocking.

    The salvaged diamond-muntinA strip of wood or metal separating and holding panes of glass in a window sash. Each pane of glass (or each "insulated glazing unit") separated by a muntin is called a light. windows are not at all energy efficient, but our aesthetic and budget overruled a more modern option. We balanced this choice with a homemade second skin—basically, interior storm windows made from acrylic sheeting, insulated compression tape, and rare-earth magnets.

    Reasons and Means for Working Efficiently
    Because of the project’s modest size and because it ultimately became a business need and not just a personal one, it made sense to swiftly complete it in a matter of months. To make things easier, we enlisted people that we had worked closely with in the past—Michael Gorman and Martin Philbey, trusted carpenters who have worked with me at Renovator’s Resource.

    Lessons Learned

    Be careful, follow your intuition, and enjoy
    This project, although very small, became a research project. It was the first time our crew had acid-etched a slab. Unfortunately, the water drops IcyneneOpen-cell, low-density spray foam insulation that can be used in wall, floor, and roof assemblies. It has an R-value of about 3.6 per inch and a vapor permeability of about 10 perms at 5 inches thick. spray created multiple sealed water marks on the new concrete, preventing the acid stain to etch those spots. It is okay for our own small office, but we would have been very disappointed had this happened on a client’s project.

    It was also the smallest renovation our crew had ever attempted. The simplicity of the space was the guide on how to finish it, and matching the new walls to the existing ones proved quite easy. The success of the project certainly supported the value of a hands-on, minimalist design approach.

    The Taj (or "Garage Mahal," as we affectionately call it) has become our getaway. Any challenging work tasks—like writing, brainstorming, and quiet contemplation—occur away from our main Solterre office, just two blocks away, in the Taj. We have put a sign on the wall—WELIKEIT—that I had purchased at a local auction. I always planned to research its meaning; it’s likely a Mikma’q (a local First Nations’ group) name. Though on one quiet evening it came to me: “We Like It.” And we do.

    It is quite likely that our kids will rally to have it as their own getaway in a few years. We may have a battle on our hands then, as it is a special place.


    —Jennifer Corson, M. Arch., is a Partner at Solterre Design in Halifax, Nova Scotia. She is also a member of GreenBuildingAdvisor.com's team of advisors.

    Tags: , , , , , , , , , ,

    Image Credits:

    1. Jennifer Corson

    Register for a free account and join the conversation


    Get a free account and join the conversation!
    Become a GBA PRO!