Image Credit: Peter Yost The existing 12 by 12 foot kitchen has four doorways and three large windows. The stove and refrigerator locations were not planned; the appliances "ended up" in each space. This is looking at the west wall of the kitchen with the porch visible through the kitchen door and window.
Image Credit: Peter Yost On the east wall of the kitchen, the sink countertop space is the ONLY countertop in the entire kitchen.
Image Credit: Peter Yost The kitchen addition started with demo of the back porch and the 2nd floor gable exterior (failing stucco and lathe). Note the new kitchen back door; this door was purchased for swing and hinge setup for the new kitchen addition back door but installed temporarily inside and out backwards in the existing kitchen.
Image Credit: Peter Yost Sono-tube piers extending below the frost line make up the SIPS kitchen addition foundation. The SIPS floor/pier foundation was selected to minimize use of concrete and to make it easy for weekend warriors to get the foundation done.
Image Credit: Peter Yost Pressure-treated Parallam beams are installed on the PT posts, which are rebar-cored to the concrete piers. Note the blue capillary break membrane just under the posts, isolating the concrete from the wood in the assembly.
Image Credit: Peter Yost Using retired climbing gear to cinch the SIPS floor panels firmly together. And a big sigh of relief as the floor panels line up perfectly with respect to the the existing kitchen's floor assembly.
Image Credit: Peter Yost A rubber gasket, two beads of sealant, and then later an interior bead of sealant form the air seal detail where the SIPS floor meet the SIPS wall panels. It's a belt-and-suspenders and then some approach to address the Achille's Heel of SIPS assemblies: air sealing panel joints.
Image Credit: Peter Yost 3+ carpenters (Hey, I was mostly taking pictures...) installed all of the SIPS panels in less than a day, including the roof panels without a crane or lull.
Image Credit: Peter Yost The dollops of spray foam prove that the keyhole channel cored into every Winter Panel SIP joint is air sealed. You drill holes through the interior plywood spline then spray foam insulation into one hole until spray foam expands out the adjacent hole. You can also see the spray foam where the floor and wall SIPs meet the existing split-faced concrete block.
Image Credit: Peter Yost The SIPS addition was weathertight in about a day and a half from foundation to roof membrane and wall housewrap.
Image Credit: Peter Yost With the SIP addition weathertight, demolition of the west wall concrete block in the existing kitchen is done, block by block.
Image Credit: Peter Yost With the old kitchen wall down, the girls explore the new space and the renovation crew takes a break. Each phase of the project was carefully timed to accommodate the office "day jobs" of the crew and the family schedule.
Image Credit: Peter Yost Ready for gypsum board. Note the final interior sealant at the roof-wall joint and the membrane strips at each panel joint.
Image Credit: Peter Yost Pre-finished red birch flooring matches the existing kitchen floor well. We pretty much had to run the new flooring perpendicular to the existing to span the block wall section at the old wall plane.
Image Credit: Peter Yost Both the window opening and the window unit are flashed. With the very low drying potential of the SIP panels, it's really important to back-vent the cladding installation (furring strips used here) to maximize the drying potential of the assembly to the exterior.
Image Credit: Peter Yost All the kitchen wiring (outlets, interior lighting, exterior lighting) was carefully planned to avoid any routing of the SIPs, including this baseboard raceway.
Image Credit: Peter Yost During renovation of the west bedroom just above the kitchen, access to the knee wall space was planned to accommodate subsequent installation of the high performance kitchen exhaust fan.
Image Credit: Peter Yost The weatherlock mudroom just off the kitchen addition is just about a New England necessity.
Image Credit: Peter Yost **A multitasking island** The long central island has room for cooking and entertaining.
Image Credit: Daniel Morrison **A little space can go a long way** The SIP addition extends the kitchen only about six feet, but results in a spacious room.
Image Credit: Daniel Morrison The dimensions of the kitchen addition were designed to a two-foot module to minimize SIP cut-off and cut-out waste, integrate with existing roof rake details, and to accommodate a 5 by 5.5 foot mudroom as part of the addition.
Image Credit: Steve Baczek
Converting a back porch to living space makes a cramped kitchen roomy — and adds a mudroom to boot
Old houses didn’t need big kitchens because they weren’t the central gathering spot that today’s kitchens are. The 12-ft. by 12-ft. kitchen in the house my wife, Chris, and I bought ten years ago was just such a space: small and dark. It was pretty typical for a 100-year-old New England home, but it was challenging for how a kitchen works in the 21st century.
We needed more space, more natural light, and better placement of the workstations, but the four doors and three windows limited our options. The most logical approach to designing a more functional kitchen was to expand out the back side of the house, but what would the configuration be? It was really helpful to work with architect Steve Baczek, who provided us with about six different options for the locations of major stations: sink, stove, refrigerator, dining, food prep. Interestingly, the layout that looked best involved the least reworking of major systems: space heating, electrical, and plumbing.
Choosing a building system
I have to admit something here: I am a member in good standing of both the Recovering Remodelers Association and the Wannabe Building Scientist Society. I want our home to be cost-effective, safe, and energy-efficient, but if I get to use new techniques, new tools, or new materials, I probably can’t resist “experimenting.” And I need projects that I can do largely on my own and that are staged according to lots of weekend and vacation work.
I had never built with structural insulated panels (SIP) before, and the kitchen/mudroom addition seemed like a perfect fit with a pier foundation I could do on my own. I knew that the toughest part of SIP construction is air sealing the panel joints, so I went with our local Winter Panel system because I like the panel joint detail the best and because the company manufactures polyiso foam panels, the highest R-per-inch on the market.
Resource efficient by design
Perhaps the trickiest part of this project was working out the dimensions to fit the existing west wall configuration and to minimize SIP cutoff waste. We pushed the addition just as far as we could to the south, right up against the downstairs bathroom window. This meant a pretty tight mudroom (6×6 outside dimensions), but it made the overall length exactly 18 ft., a 2-ft. module. In terms of the width, we had to honor the distance to the detached garage and make sure that the shed roof of the addition could still tuck under the existing rake of the west gable on the north end. It turns out that a 6-ft. width gave us the 2-ft. module on the floor, walls, and roof panels with a 4-in-12 pitch. It would be really tight at the north corner of the addition at the existing rake, but we double-checked this several times and even did a rough mock-up to ensure we had the room. We also ended up with less gypsum board cutoff waste on the interior.
The new home center
Our family has gone from avoiding the kitchen to living in it. The new space is great not only for cooking and dining, but also for homework and family game night. The large island draws the new and old spaces together, and the mudroom is a great weatherlock all year round. Although the kitchen addition and other work on our home have expanded the conditioned space by about 20%, our energy bills continue to decline each time we tackle yet another high-performance renovation.
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An R-38 floor is still cold
The heat loss from the R-38 SIP floor in the addition is no greater than the heat loss from the R-38 walls and roof. The only problem is that we don't walk on the walls and roof. When we step from the kitchen floor over the basement to the kitchen floor of the addition in the middle of winter, the 5+ degree surface temperature drop is more than a bit uncomfortable in a home with a no-shoes-inside policy. Just as soon as I can get the lumber stock off the racks I built under the kitchen addition, I will be adding another layer of polyiso rigid insulation to the underside of the kitchen addition floor.
Too many windows
In the kitchen (and the front home office, for that matter), we went with large double-hung windows (2.5 by 5) in the addition, with a pattern that matches the existing kitchen window layout. That adds up to 25% of the total exterior wall area of the kitchen, and it is simply too much. We love the way the banks of windows make the kitchen feel, but the heat loss in winter and solar gain (especially to the west) in summer is a feel we like a lot less.
If we had it to do over again, we would take out at least one if not both of the west wall kitchen addition windows. On the other hand, maybe really high-performance window treatments for both heat loss and solar gain will be available soon and give us the best of both worlds.
General Specs and Team
|Additional Notes:||The original kitchen was 144 sq. ft.; the addition is 72 sq. ft. of kitchen space and 36 sq. ft. of mudroom. The approximately $18,000 cost of the kitchen addition/renovation does not include the author's labor or the appliances (stovetop, oven, refrigerator).|
Construction crew: Christian Yost, Tom Henze, Ron Benson, Dave Gauthier (Winter Panel), Peter Yost Roofing: Walker & Sons, Hinsdale, N.H.
Foundation: Concrete piers, Parallam beams
Floor, walls, roof: 6.5-in. SIPs
Wall cladding: Back-vented, factory-primed, finger-jointed cedar lap siding
Roof cladding: Galvalume standing seam metal roofing
Windows: Marvin Integrity double-hung metal-clad wood
Refrigerator: Energy Star Amana (bottom freezer)
Windows: U-factor = 0.32; SHGC = 0.28; VT = 0.48
Floor, walls, roof: R-38 polyisocyanurate foam
Kitchen faucet: Brizo SmartTouch electronic touch/motion sensor activation
Dishwasher: Energy Star Frigidaire
Indoor Air Quality
- 150-cfm high-performance Fantech exhaust fan
Green Materials and Resource Efficiency
- Pier foundation
- Salvaged maple trim
- Kitchen cabinets reused in garage and basement
- Kitchen sink donated to ReNew Salvage for resale
- Existing stove reused in family apartment complex
- Locally quarried and finished granite countertop