Case Study #5 – Eighteen months to big cost savings: Applying 75 Years of Technology Improvements to Drastically Reduce a Home’s Energy Costs

Chuck and Collette's detailed records show annual utility savings of over $4000 from their efforts.

Fifteen years ago, Chuck and Collette bought the perfect house for two – a midcentury modern single-family residence located on a wonderful, wooded property in Lincoln. It was situated perfectly on the lot and sensibly built with the roof overhang designed to shade in summer and allow penetration of warm sunshine in winter.  As energy costs rose and concern over greenhouse gas emissions increased, however, this great 1950’s design was not enough. The CFREE subcommittee of Lincoln’s Green Energy Committee offered guidance to improve the energy efficiency of their perfect home.

A MassSave inspection came first with a thorough examination of the home’s envelope –walls, roof and windows. The next step was analysis with a thermal imaging camera. Although the Sizers had thoroughly sealed the house, there was still significant heat loss in winter, mostly through the roof, steel-frame windows, and the fireplace.

Better Comfort from New Roof Insulation

The 70-year-old rubber roof, in clear need of repair, was replaced and 6 inches of rigid insulation was installed, for an R-value of 33. This level of insulation immediately added to the comfort of the home while preserving the midcentury modern architectural design of the home.  Solar panels were now mounted, utilizing federal tax credit incentives to greatly reduce cost. In hindsight, a few more inches of roof insulation would have been beneficial in the long run and might not have been noticeable.

Awesome New Windows and Heat Pump!

These eight are windows work miracles on sunny winter days, letting in the sun's heat and keeping it in.

The steel frames on the original windows led to condensation and rotted windowsills. Many windows needed replacement. The eight large south-facing picture windows in the living room could not be replaced with standard windows without destroying the architectural features and ambiance of the room. Custom triple-pane Schuco glass assemblies ordered through European Architectural Supply were installed. These windows have an incredible R-value of 8! Good quality double-pane windows have less than half that.

The old gas furnace was limping.  The Sizers opted for full elimination of fossil fuel heat and hired NetZero to install a 3-ton Mitsubishi heat pump. The well-insulated roof and new windows keep most of the heat in in winter and the heat pump efficiently replaces what does get lost. Adding solar reduced the cost of utility bills to just under $1000/year.

The final purchase was the switch to an electric vehicle which charges overnight from a 110-volt outlet. The total dollars saved, including the savings on gasoline, have been regularly calculated at just over $4000 annually. Good planning and focus enabled completion of the whole project in just 18 months!

This case study was developed by CFREE (Carbon Free Residential - Everything Electric), a subcommittee of the Lincoln Green Energy Committee. CFREE provides guidance on how households can reduce use of fossil fuels and decrease greenhouse gas emissions to help Massachusetts meet statewide emissions limits set for 2030, 2040, and 2050. It also provides information about state and federal incentives that help reduce the cost of such changes. For guidance on such projects at your home, contact: Lincolngreencoach@gmail.com. For more information visit: lincolngreenenergy.org.