Skip to content

Personal tools

Home > Preservation > Energy Efficiency and Sustainability > Lyman Estate Weatherization and Energy Efficiency Project

Lyman Estate Weatherization and Energy Efficiency Project

Lyman window removal
Removing the Palladian window at the Lyman Estate mansion in Waltham, Mass. The window will undergo conservation and be re-installed as part of an energy retrofit.

The Lyman Estate mansion underwent preservation work and system upgrades to become an energy efficient historic building. The project aimed to reduce energy consumption by fifty percent while still adhering to the preservation philosophy that defines Historic New England. We hope to demonstrate how historic homeowners can achieve significant savings in energy without sacrificing the elements and details that give character to their buildings. The project followed these basic steps:

  • testing
  • window conservation instead of replacement
  • sensitive use of storm windows
  • air sealing and careful use of insulation
  • more efficient heating systems, equipment, and smarter use.

We are also exploring other options for future improvements such as alternative energy use, building controls, and gray water irrigation.

Testing and Energy Audits

An energy audit is an assessment of the many different factors that contribute to the energy efficiency of a structure. Although it can take many forms, an audit should look at the facility’s energy use to understand consumption and identify conservation measures that might help the homeowner save money. Energy conservation measures typically focus on decreasing the amount of air getting into the building, because cold air will be drawn into a warm building, making it more difficult to heat, and smart use of insulation. An energy auditor might use blower doors, a giant fan that helps determine how much the building is leaking air, and infrared cameras that help pinpoint otherwise undetectable areas of air leakage and heat loss.

Establishing a baseline of energy consumption was important for the Lyman weatherization project. If we are to achieve a fifty-percent reduction in energy then we need to understand our history of use. An auditor analyzed the energy data, performed blower door tests, and crunched the numbers on the work we were proposing in order to estimate the benefits on energy consumption. Although this established the baseline, we performed these tests at different stages of the project to understand how each conservation measure affects energy efficiency. This information will prove very valuable to homeowners trying to determine how to begin this process.

Windows out
The Lyman Estate windows have been removed for conservation.
Air Sealing and Insulation

Air sealing and insulation go hand in hand as weatherization measures. Smart, controlled use of both techniques can drastically change the energy consumption of a building. But buyer beware: historic buildings are very, very different from modern buildings and any action you take should be carefully considered. The biggest pitfall in a historic house is the promise of wall insulation. Homeowners predicting big savings enlist contractors to fill their walls with insulation. But if the conditions are not right and the wall construction does not include proper water barriers, homeowners run a high risk for mold, mildew, and rot.

Although wall insulation was not part of the project, air sealing and insulation were major components. In keeping with our preservation philosophy, these techniques were executed in a way that is reversible in the future. That means we will be able to remove any materials we add some time in the future and be left with the original historic fabric unharmed. Some products used in home efficiency projects are new. Their long-term performance is not yet understood, and they are designed to be permanent and not reversible. We insulated the attic to “cap” off the building and help contain heat. We are experimenting with air sealing techniques that are reversible and therefore suitable for historic properties.

Efficient Heating Systems, Equipment, and Smarter Use

As part of the weatherization project we worked to improve the heating plant of the mansion at the Lyman Estate using the following measures:

  • Converting the fuel source from fuel oil to natural gas
  • Improving duct work and installing smarter thermostats to get the most out of the heat
  • Upgrading catering kitchen equipment for efficiency and performance

Most importantly we need to analyze how we use the spaces and how we manage energy. Our basic approach to energy efficiency at the historic properties can be found on our White Papers section.

Read project updates in Lyman Estate News.

Lyman Estate Weatherization and Energy Efficiency Project