Deep Energy Retrofit (DER) Workshop January 12, 2013 Sustainable Living Resource Center Cottekill, NY Thank you Manna Jo Greene

Why DER is Needed … Fuel sources, therefore fuel prices are volatile, provides “hedge” Operating costs burden homeowners, money exits local economy Current weatherization/Home performance strategies (insulation placed between studs, 15% reductions, incremental benefit) vs. Deep Energy Retrofit strategies (install insulation to exterior, air seal, reduce mechanicals, 65 – 75% reductions, provides step function boost benefit) Benefits to preserving entrained energy of existing stock

Age of Existing US Housing Stock Almost 60 million housing units built before the first oil embargo in 1973 Most homes in the US could benefit from some sort of energy retrofit. There is a huge potential market for improvements. Source: American Housing Survey 2005 © Marc Rosenbaum - EnergySmiths

Candidates for DER … both built within the past 20 years Credit: Marilyn Kaplan Credit: Tony Abate

There are several strategies for implementing a DER; this Pilot focused on the exterior insulation strategy for the following advantages: Allows continuous, un-bridged insulation layer Facilitates exterior air barrier installation Can be installed while the home is occupied Thickness of insulation is not limited by wall thickness Eliminates the problems caused by blocking, bracing and other internal framing elements causing missed (un-insulated) wall cavities

Condensation Potential All buildings go through wetting and drying cycles. The drying ability must be greater than the wetting potential or moisture related problems will result. Chart shows the period of time during which the outdoor temperatures reach below indoor dew point, making condensation possible, and it will occur somewhere within wall and roof/attic assemblies. This is important because the building must be able to dry at a greater rate than it gets wet. Heat loss is the main moisture mover in winter, but as we insulate the building, we decrease conductive heat loss and therefore improve the drying potential of the building.

Temperature gradient across a wall Note that the temperature of the interior face of the sheathing is 20F – well below the dewpoint of the inside air. If air from the inside reaches the sheathing in any significant amount, condensation will occur. Air leakage through a small hole can move 100 times more water into a building cavity than is transported by vapor diffusion, so air barriers (AB) are more critical than vapor diffusion retarders (VDR) With 2 inches of polyiso at R-13 the interior face of the sheathing is 41F – little condensation risk. Applying exterior insulation (especially continuous high-R value insulation) will increase the winter temperature of wood sheathing underneath, decreasing the wetting potential, notice the ‘knee’ in the curve In Cold Climates, building durability is in a large part determined by how effectively the building exterior envelope handles moisture and temperature gradients. Thermal bridging causes cold spots on the interior side of exterior walls when the temperature of the wall is below the dew point of the indoor air. In winter, moisture is evaporated into relatively dry indoor air from people, cooking, basements… As air circulates over colder exterior elements (where the thermal bridges are) it cools and reaches dew point, dropping moisture and potentially causing moisture damage © Marc Rosenbaum - EnergySmiths

Foam (SPF) placed ON the wall is a strategy that reduces thermal Heat flow and R values in walls Foam (SPF) placed ON the wall is a strategy that reduces thermal bridging. 2x6 cellulose 18% wood Nominal R21, Actual R = 15.8 77% of nominal R21 2x6 cellulose 18% wood 4” SPF Nominal R45, Actual R = 41.0 90% of nominal R45 Credit: Marc Rosenbaum (Energysmiths)

Major Renovation Invokes Building Permit … eliminates “kicking the can”

Air Infiltration Measurements ACH before DER ACH after DER

Average Total MMBTU / Unit (4 Utica Houses)

Phase II … PON 2254, Exploratory Envelopes Develop repeatable strategies that scale Achieve following technical objectives: Whole house assembly, R > 25 Total air leakage, < 0.25 CFM50 / ssf Labor & material / ssf = $10 Combine strategies to optimize influence Acquire more data, 22 is more than 4, statistics

5 Building Science Contractors Selected, 22 homes Taitem Engineering (retrofit 4 houses) Snug Planet NAHB – Research Center (retrofit 3 - 4 houses) SIPA IBACOS (retrofit 8 houses, and 1 control) Green Homes America Verdae (retrofit 3 houses) Mulder Construction Levy Partnership (retrofit 3 houses, MF) Sto Corp

Material Intensive in both directions …

Reduced Mechanical Systems enables energy reductions

Continuous Mechanical Ventilation that works

Homeowner Engagement, More Emphasis needed on promoting “comfort” Air quality Safety (removal of auxiliary heat sources) Insurance premiums (no ice damming, falling ice) Building quality/integrity Value the ‘resilience’ of the solution Better sound attenuation (indoors is quiet) Improves longevity of equity investment Thermostat settings at occupant desired levels

Direct Benefits of Screwing 4” of Rigid to Exterior Works daytime, nighttime Works summer, winter Eliminates undesirable air leakage Employs local labor Invokes building permit, which brings house to code Works when grid is de-energized Works on cloudy days Works when wind is not blowing

Long Ways away from a “Program” … Allies Needed Regulators Bank appraisers Code officials, consistency Siding contractors Realtors Insurance underwriters Project agent Manufacturers discounts Slush fund investment to code comply homes Policies Needed Carbon taxes Fuel oil taxes to fund Bldg Science kBTu/ft2/yr threshold Reward for less

Contact… gap@nyserda.ny.gov http://nyserda.ny.gov/advanced-buildings Greg Pedrick, C.E.M. Buildings R&D Project Manager 17 Columbia Circle Albany, NY 12203 (518) 862-1090, x3378 gap@nyserda.ny.gov http://nyserda.ny.gov/advanced-buildings