Energy Efficiency in Historic Properties

​​​​​​​​​​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:

• City of Phoenix Guide to Window Repair and Replacement for Historic Properties. The City of Phoenix Historic Preservation Office has created this guide under the direction of the Historic Preservation Commission's Window Advisory Committee. This committee consisted of a wide range of community representatives, contractors and architects. The Historic Preservation Commission also reviewed and approved the guide on August 15, 2011.
• Grants: The City offers matching grants to property owners to improve energy efficiency in historic windows. Grant eligible work items include repairs that make existing historic windows more weather tight, the addition of window films that reduce solar heat gain, retrofits of historic window sashes with thicker single pane glass, hard coat low E glass or dual pane units, and window insulation measures.
  
• Other Energy Efficiency Resources:​
  • Arizona Public Service Residential Energy Saving Options​ and Salt River Project Energy Savings Programs​​ - Find out how to qualify for rebates to make your building more energy efficient.
  • Weatherizing and Improvin​g the Energy Efficiency of Historic Buildings - Explore the National Park Service's new website to discover cost-effective measures to make a historic building's envelope more energy efficient while also having a minimal impact on the historic building's design and materials.
  • Green Stories​ - Visit this website offered by the National Trust for Historic Preservation to find out how historic buildings are the "greenest" type of building.
    
  • National Park Service Preservation Brief 3: Improving Energy Efficiency in Historic Buildings​ - Find out how you can improve the energy efficiency of your historic building.
    
  • National Park Service Preservation Brief 9: The Repair of Historic Wooden Windows ​- Find out how you can repair your wooden windows and weatherize them.
  • National Park Service Preservation Brief 13: The Repair and Thermal Upgrading of Historic Steel Windows ​- Find out how to repair and thermally upgrade your historic steel windows.
  • Technical Historic Preservation Bulletins by the Phoenix Historic Preservation Office​ - This includes more guidance on repairing steel casement and wood windows, and information on paint removal, cleaning and re-pointing of masonry buildings.