Energy Efficiency and Windows in Historic Properties

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​​​​​​​​​If you are wondering how to make your historic building more energy efficient, there are some new resources available to you. The technology for enhancing the energy efficiency of historic buildings is getting better all the time.

Did you know? To identify the best options for improving a historic building's energy performance, an energy audit is typically a great place to start. In Phoenix, residential customers of Arizona Public Service and Salt River Project are eligible for $99 energy audits. An energy auditor uses a number of instruments to evaluate the function, efficiency and interactions of the energy systems in a building. A comprehensive home assessment report will help you decide which upgrades make the most sense to pursue, and will identify any additional rebates available to you to make these improvements.

Energy efficiency solutions: Most energy audits will recommend easy improvements you can make to increase energy efficiency without spending much money or time. These include replacing incandescent light bulbs with compact fluorescent bulbs, adjusting thermostats, curing water leaks, replacing high flow shower heads, adding window treatments, and planting shade trees. Other "big ticket" work items may or may not be worthwhile for your building. Some improvements are worth the investment and provide a quick payback while others can take 10 years or more to recover initial costs. Larger work items can include duct sealing, installation of an energy efficient heat pump or air conditioner, addition of insulation, duct sealing, installation of energy efficient water heaters and appliances, and retrofits or replacement of windows. Energy rebates are available for some of these improvements through energy providers.

What about historic windows? Although conventional wisdom may call for their replacement, energy auditors usually find a number of other energy efficiency measures that are more important and cost effective to deal with first. Sometimes windows do need to be replaced. But there are also other excellent and more cost-effective solutions available to greatly improve the energy efficiency of existing historic windows. This includes window repairs and weatherization measures; interior insulated blinds, curtains and shades; window films; and installation of thicker glass into existing window frames and sashes.

​Resources: The city of Phoenix Historic Preservation Office is committed to providing historic property owners with more resources to make their historic properties more energy efficient: