Image Credit: Russell Campaigne
Image Credit: Russell Campaigne The angles of the house and garage create a funnel that draws cool breezes through the screened porch. Solar panels are in an inconspicuous location, high on the south roof.
Image Credit: Olson Photographic The core living area is open with plenty of south-facing windows, creating a bright, functional, and efficient space.
Image Credit: Olson Photographic Construction detail section view WAY AHEAD OF THE PACK: 22.5 MMBtu/year. It doesen't take extreme design to get an extremely practical and energy efficient home. A functional layout, well thought out mechanical systems, and serious attention to details resulted in a comfortable home with a traditional feel and 21st century performance.
#An Efficient Design and a Carefully Detailed Envelope Add up to Big Energy Savings
Craftsman bungalows are celebrated for being comfortable, practical and carefully crafted from local natural materials. This LEED Gold home in South Glastonbury, Connecticut, incorporates all of these qualities and more. To meet the homeowners’ goal of creating an enjoyable and economical place to retire, CK Architects penned an attractive, efficient, and adaptable plan. A meticulously detailed building envelope, a discretely mounted photovoltaic array, and a ground-source heat pump keep the home affordable.
Let nature work for you
Beneficial natural conditions paired with good design choices helped maximize the project’s sustainable features. An L-shaped house plan and a central screened porch let cooling breezes pass right through the house. An existing clearing made it easy to install the horizontal heat-pump loop and then cover it with a meadow of wildflowers. The landscaped portions of the site contain large beds of noninvasive, drought-tolerant plants, minimizing the need for irrigation and yard work.
Designed for easy living
Farmed white cedar shingles, fiber-cement siding, and cellular PVC trim ensure that the home’s exterior is low-maintenance and durable. CK Architects left the core living area open with plenty of south-facing windows, creating a bright, functional, and efficient space. Less frequently used, the guest rooms are deliberately isolated from the rest of the house, allowing John and Karen to reduce their heating demands when visitors aren’t around.
Early actions pay off
The build team’s commitment to environmental responsibility made joining the LEED for Homes pilot program an easy decision. Doing this early in the process guided smart choices on everything from initial site preparations to interior finishes. Architect Russell Campaigne estimated that the green building methods added about a 5% premium over a comparable home built to code. With utility bills for the first year averaging less than $100 a month (pretty good considering Connecticut has some of the highest electric rates in the country), it seems that the investment is paying off.
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Lessons Learned
Russell Campaigne referred to Energy Star guidelines when planning the insulation and air sealing for the house. Although the blown and batt fiberglass tested and ultimately performed very well, sprayed-in-place foam would have definitely been easier to install. After describing the difficulty in detailing the fiberglass correctly, Russell commented, "the contractor would have been happy to pay the extra cost of the foam."
He also found that the screened breezeway performed better than expected. Shade trees and the funnel shape of the house made it much cooler in summer and there was plenty of solar gain to help break the chill in the early months of spring.
Builder Bob Dykins' take on green building is that there needs to be more focus on methods that foster durability. On this project, planning siding laps to fall at the tops of windows, using strips of tarpaper as additional sill flashing over the siding below, and thoroughly air sealing below wall plates and around openings were a few simple steps that will make a long-term difference in the home's performance.
General Specs and Team
| Location: | South Glastonbury, CT |
|---|---|
| Bedrooms: | 5 |
| Bathrooms: | 2.5 |
| Living Space: | 2966 |
| Cost: | 250 |
Builder: Bob Dykins, Glastonbury Housesmiths
Architect/designer: Russell Campaigne, CK Architects
Engineer: E2 Engineers
Construction
Foundation: Poured concrete (50% slag) basement with 10-in. walls insulated with 2 3/8-in. exterior semi-rigid fiberglass board plus 2-in. interior rigid XPS foam (R-20 total);
Above-grade walls: 2x6, 16 in. o.c.; blown-in fiberglass (R-21)
Windows: double-pane, low-e, argon-filled; U-factor = .31 (R-3.2)
Roof: 2x10 and 2x12 rafters, 16 in. o.c.; vented; blown-in fiberglass insulation; cathedral ceiling R-30, flat ceiling R-43
Garage: detached
Energy
- Ground-source heat pump
- ERV (Venmar)
- Southern exposure and window layout provide 100% daylighting
- CFL lighting in most fixtures
- Energy Star appliances
- Spray-foam air sealing before fiberglass insulation install
Energy Specs
Heating/cooling: ground-source heat pump (Water Furnace; EER 30, COP 5) with horizontal ground loop
Water heating: Desuperheater with natural-gas backup
Annual energy use: 22.5 MMBtu
Water Efficiency
- Low-flow sink faucets and showerheads
- Drought-tolerant landscaping
Indoor Air Quality
- MERV 8 air filtration
- Central vacuum exhausted to exterior
- Prefinished hardwood floors
- Low-VOC finishes
- Low-formaldehyde composite-wood products
Green Materials and Resource Efficiency
- Engineered lumber
- Job-site recycling and ordering efficiency
- Prefinished bamboo flooring
- Composite doors and trim with recycled content
Alternate Energy Utilization
Photovoltaic system: 3.25 kW; cost, $12,500 after rebates
Certification
LEED for Homes score (points earned/available): gold (80.5/130)
HERS Index (new rating system): 33
7 Comments
If the HERS score is
If the HERS score is 33...doesn't that mean that it will use 67% less energy than the comparable built to code "reference home"?
Where does the 75% lower utility bill come from?
Another reason that it may be
Another reason that it may be misleading to claim 75% reduction in utility bills....The more efficient homes pay an additional utility dollar cost per unit penalty when you average in the base fees.
In other words even if you use 67% less energy..your bill will not be 67% less...you still have to add the base fees.
I like the Architecture, The
I like the Architecture, The detached garage and the careful use of windows.
Clarification of energy savings claims
John, you have a good point. The case study stated that there was a 75% energy savings over a comparable home. The reason that there might have been a difference between this number and the HERS score is that the HERS rating is a theoretical number whereas the 75% number was based on more than one year of actual energy bills. The flaw is that I did not present clear data for what represents the average home. I am editing the text to more clearly represent the data that we do have for this house. Thanks for your input.
$250/Sf
Is $250/SF for almost 3000Sf ($741,000) really sustainable?? CAn the average person in CT afford to live there?
framing techniques
is there a reason why you chose to space the studs 16" O.C as opposed to 24" ? also, is using a thicker foundation more efficient in costs and energy use?
Greenwashed
There's nothing green about the building products itemized. You just introduced a whole bunch of chemistry for the family to breathe and absorb through dermal exposure. I applaud the use of the ERV Venmar to help control the indoor humidity levels, but for the climate zone wouldn't an HRV be more appropriate? A merv 8 filter is a why bother solution to doing nothing at all. May be good for capturing large particulate like dog hair. A suggestion would be to incorporate a merv 13 at minimum and add activated carbon filtration to adsorb some of the emitting chemistry from the air.
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