After shivering for 20 winters inside their drafty 1576 sq ft 1945 Garrison Colonial in Melrose, MA, owners David Fink and Barbara Simko requested a MassSave energy audit. The auditor stated that the house would be an excellent candidate for the National Grid DER program. Thus began their journey towards zero net energy.

The owners initially planned to remodel the house by replacing the kitchen and building an addition. Working with architect Steve Baczek and energy efficiency specialist Mike Duclos, the design gradually evolved via the National Grid DER program to one that did not add square footage. Instead, the project focused on energy efficiency, making super-insulation improvements per DER guidelines, lowering window heat loss, increasing window solar gain, and recovering living space occupied by obsolete mechanical systems.

The super-insulated all-electric DER renovation home includes full envelope insulation and air sealing, high solar gain triple pane windows, new doors, and new heating and ventilation equipment. The chimney and existing oil fired steam heating system were removed and replaced by two mini-split air source heat pumps. The existing gas hot water heater was replaced by an electric heat pump water heater. An HRV was added to recover exhaust air heat and provide adequate ventilation. A drain water heat recovery heat exchanger was installed in the basement to recover heat energy normally lost down the shower drains. Because the southern facing main roof was ideal for PV, a high efficiency PV array was added to solar power the house to reach the zero net energy goal. The project was completed in October 2013.

The DER project was one of six NESEA ZNEBA finalists in March 2015. For a 1 year time period starting on Jan 7th of 2014, actual performance exceeded zero net energy. Measured performance was:

• 9103 kWh – PV Energy Production (=100%)
• 8395 kWh – House Energy Usage (=92.2% of PV Production)
• 0708 kWh – Net Energy Surplus to Grid (=7.8% of PV Production)