Low impact sunroom in Rhode Island

Great details make this addition better for the pocketbook and the environment

The owners of this traditional RI home wanted to replace a cramped enclosed porch with a comfortable multipurpose addition, better views of a nearby river and a better expression of their eclectic taste. Although the clients’ initial plans didn’t specifically focus on green building, Joseph Cracco, of Modern Yankee Builders, challenged himself to raise the project’s level of sustainability without raising the cost. The result is a bright and airy family room, an expanded second floor office and a new basement that perform better than the family had imagined possible.

You could say that the motto of Joe’s team was “tread lightly”. Almost 19 tons of concrete were reclaimed by grinding the old foundation into gravel for road beds. The rest of the construction debris was hauled to New England Recycling, in Taunton, MA, where about 84% of it was separated for reuse. After the original porch was carefully deconstructed, the new work shared as much of the original footprint as possible. Site disturbance was kept to a minimum - existing bushes were temporarily moved then replanted; turf was quickly re-established in some areas and replaced with planting beds in others; the new gas line was even tunneled to avoid digging a trench in the front yard.

Modern Yankee Builders did all this - on top of the steps they took to make the addition durable and energy efficient. The structure is built with advanced framing on top of a thoroughly waterproofed ICF basement. To allow for the decorative rafters and sheathing inside the new space, and to create a good thermal break, XPS insulation was installed outside of the roof deck. The whole exterior got a well sealed drainage plane and air barrier. After that, Sleepers, CDX, a self adhesive water shield and 30 year asphalt shingles created a fully vented roof surface and hard-wearing FSC certified cedar shingles wrapped the walls. Joe’s dedication and attention to detail paid off. The homeowners got a place they can be proud of for years to come, with little added burden on the budget or the environment.

Team:
Builder: Joseph C. Cracco, Modern Yankee Builders
Architect/Designer: Katrin Boening and Sean Solley, Solleydesign

Specs:
Location: Barrington, RI
Completed:2007
Cost: $180,000 including site work and landscaping
Size: 635sq.ft.(275 sq.ft. room added to basement, 275sq.ft. 1st floor family room/mudroom, 85sq.ft. additional space added to existing 2nd floor office)

Construction:
Foundation type and R-value: ICF basement (R-22)
Wall construction and R-value: 2x6,24” o.c., XPS sandwiched within headers (R-10), fiberglass batts (R-19)
Windows: double glazed, low-E (R-2.9, SHGC - .29)
Roof construction and R-value : 2x6 T&G roof decking over exposed rafters, 4” XPS foam board with taped seams(R-24), 5/8” OSB sheathing and 2x sleepers over rigid foam

Energy specs:
Heating equipment: new hydronic baseboard tied into existing loops on each floor of house
Air conditioning: (only in existing top floor) variable speed air handler, condenser (13 SEER)

Water efficiency measures used in this project
- Reduced lawn area (less irrigation demand)

Energy efficiency measures used in this project
- Bank of windows providing ample daylighting and natural cooling
- ICF foundation
- Continuous XPS installed above roof decking (virtually no thermal bridging)
- Rigid foam insulation built into window and door headers
- Extremely thorough air sealing
- Electronic programmable thermostat
- Variable speed air handler with 13 SEER condenser

Green materials and/or resource efficiency used in this project
- Ensured durability through meticulous detailing of drainage and ventilation
- Sided with FSC certified cedar shingles
- Demolished foundation was ground into gravel for reuse
- Other construction debris was hauled to a regional recycling center with an 84% recovery rate

Indoor air quality measures used in this project
- Temporary filters covered HVAC returns during construction
- MERV 11 filters fitted to AC returns after construction was complete
- All materials kept dry during construction (just-in-time delivery, tarps above and below any stored lumber)
- Formaldehyde-free Advantech OSB subfloor

Lessons Learned:
Modern Yankee’s trek to the 2007 International Builders’ Show left them pleasantly surprised at how sustainable their standard practices already were. They still logged plenty of hours of research for this addition. This not only made the results better than the clients had asked for, but further integrated green concepts into Modern Yankee’s “business as usual”, proving that quality, affordability and sustainability can all go hand in hand.

1970s Home Goes Net Zero

A deep energy retrofit that outperforms most new homes

Intensive renovation has made this modest ranch house in the suburbs of Boulder, Colorado an example of what any green builder strives for - a net zero energy home. With an extreme insulation retrofit, a 6 kW photovoltaic array, and an evacuated tube solar hot water system, the build team expects this house to produce 130% of its own energy needs. A grid tied system allows the excess electricity to be “stored” until occasional winter cold snaps demand that the 9-kW modulating electric boiler fills in.
Motivated owners, a dedicated group of designers, consultants and builders and state renewable energy incentives, allowed the project to shoot for lofty goals. Carefully balancing the value of individual improvements by looking at them as parts of a bigger system was crucial. Energy use monitoring and computer modeling helped maximize overall efficiency of the home. A Web Energy Logger (WEL) was permanently installed to monitor performance and plan for future energy upgrades.
Starting from the ground up makes it relatively easy to insulate structures like the 700ft addition included in this project. Retrofitting existing buildings is not always as straightforward. Together, Eric Doub of Ecofutures Building, and owners John and Vicky Graham decided that wrapping the home with additional 2x4 framing and sprayed polyurethane foam would be the least intrusive method. Although some of the work replaced upgrades that were only 5 years old, and the cost was on par with a typical high end renovation, continually rising energy costs made John and Vicky’s choice to create their energy efficient dream home, a great long term investment.

Team:
Builder: Eric Doub, Ecofutures Building, Inc.
Architect/Designer: Andy Johnson, DAJ Design

Specs:
Location: Boulder, Colorado
Completed: 2006 - 2007
Bedrooms: 3
Bathrooms: 3
Cost ($/sf): $81/sq.ft.basement remodel, $250/sq.ft. main floor and addition (including renewable energy systems)
Size: 1000 sq.ft. basement, 1000 sq.ft. existing main floor, 700 sq.ft. addition

Existing:
Foundation type and R-value : concrete walls covered with 1” XPS on interior (R-5)
Wall construction and R-value: existing 2x4 framing filled with blown cellulose, 2x4 framing added to exterior and filled with Icynene spray foam (R-28 total)
Windows: Duxton foam-filled fiberglass window frames with 2 layers Heat Mirror, Krypton/Argon filled (R-7.1)
Roof construction and R-value: 8” open cell foam -(SPF) and 12” blown cellulose (r-70)
Garage: attached; thermal and air separation

Addition:
Foundation type and R-value: 6” ICF crawlspace (R-30)
Wall construction and R-value: 2'x6' frame, faced with 1 ½" resilient channel on interior creating a 7" wall cavity filled with Icynene spray-foam (R-27)
Windows: Duxton foam-filled fiberglass window frames with 2 layers Heat Mirror, Krypton/Argon filled (R-7.1)
Roof construction and R-value: SIP roof (R-42) with 3.5" SPF in dropped ceiling (R-50 total)

Energy specs:
Conditioning equipment:
- Operable windows and motorized skylight for ventilation and cooling
- Solar hot water - 180 evacuated tubes, 2 - 168 gallon, insulated storage tanks (R-80)
- Backup from on-demand 9-kW modulating electric boiler
- EPA-approved wood-burning fireplace
Water heating equipment: Same as space heating
Projected total electricity consumption: 6,300 kWh/yr
Projected total electricity production: 9,600 kWh/yr
Actual : June 2008 ~300kW surplus (sold back to utility company)

Water efficiency measures used in this project
- Dual flush toilet
- Xeriscaping
- Drip irrigation

Energy efficiency measures used in this project
- Natural daylighting
- CFLs throughout home
- Direct-from-solar-tank hot water dispenser to reduce energy demand in cooking
- Insulation far above recommended standards
- EnergyStar rated ceiling fan
- Existing Energy Star washer and dryer, plus clothesline
- Separate switch to eliminate phantom loads from electronics

Green materials and/or resource efficiency
- 90% (by weight) of construction waste either recycled or repurposed
- FSC-certified lumber for framing
- Recycled plastic decking
- Water-based floor finish
- Clay plaster
- Concrete and sorghum-based countertops
- Oriented-strand board subfloor

Indoor air quality measures
- Energy Recovery Ventilator (ERV)
- Linoleum tile with low-VOC adhesives
- Formaldehyde-free cabinets
- Low-and zero VOC paints and stains
- Natural wool carpet
- Natural clay plaster walls absorb odors, sounds, & indoor air pollutants

Alternate Energy Utilization
Photovoltaic power: Grid connected solar PV (6 kW)
Cost: $25,000
Solar water heating: Evacuated tube solar hot water system provides 90%–100% of domestic hot water as well as space heating using in-slab radiant tubes
Cost: $34,000

Green Building Product Sources:
OptiMiser, Web Energy Logger
American Clay Plaster

Lessons Learned:
Aside from the obvious utility cost savings, this remodel aims for the goal of passive survivability - the ability of a building to remain habitable when utility disruption occurs during extreme outside temperatures. The actual performance of the home falls slightly short of projections - something that builder Eric Doub believes could be tempered by the use of movable window insulation. “My recommendation is to have at least some cellular shades, if just to reduce convective heat transfer.” That’s getting pretty deep into the details of energy efficiency. Good Job Eric!