Many people associate Net-Zero homes (ones which produce as much energy as they use over the course of a year) with new construction… but not Stewart and Linda Herman. They purchased a 1907 foreclosure in South Minneapolis that was in typical foreclosure disrepair and in need of complete renovation to create their Net-Zero retirement home!
Their intention was “to turn an average old house, on a standard urban lot in a very cold city, into an affordable place to live, combining net-zero energy consumption with creature comforts and the ability to ‘age in place’.”
This ambitious goal was fraught with challenges… but one which they not only achieved but exceeded. After a 15-month renovation, the result was an all-electric house that surpassed net zero – producing 17,000 solar kW hours but using only 12,000!
To achieve this goal they had to get creative. Because of its location in a densely urban neighborhood with mature trees, passive solar was out of the question. Instead, they needed to drastically reduce energy consumption and generate electricity through photovoltaic panels.
Here is how they achieved BETTER THAN NET-ZERO…
- ‘PERSIST’ system wall insulation to R-40
- Foundation insulation effectively R-30 with cocoon-method foam sheet and spray foam
- New roofing system insulated to R-80 and supporting 42 solar collectors; an additional 12 collectors are on the garage
- Captured heat: exhaust from baths and kitchen warms incoming outside air through an enthalpy recovery ventilator (ERV); excess heat from geothermal heat exchanger pre-heats water; water heater heat pump captures heat from basement air
- Triple-glazed windows cut down on heat transfer in all seasons
- Result year one is net-positive : electricity consumption 12,000 kW hours with 17,000 kW hours generated by solar panels
From the street, it looks like a nicely updated Victorian cottage. Inside, it feels like a beautifully renovated old house… with a stunning new kitchen but also filled with original woodwork that maintains its original character. Just looking at it you would never know what an exceptional home this is. But when Stewart starts talking about this amazing project you realize how unique it is!
Are you as intrigued as I was? Learn more about this thoughtful and purposeful home transformation in the owner’s writings which he generously shared in the links below.
- 1907 Home of the Future – Old House Journal
- Decarbonizing Your Retirement as you “Age in Place” – Zero Energy Project
- Innovations in a 107-Year-Old Net Positive Victorian Retrofit – Zero Energy Project
Many thanks to Stewart and Linda Herman for so graciously sharing their story and photos!
Sharlene Hensrud, RE/MAX Results HomesMSP Team – shensrud@homesmsp.com – 612-419-0560
