What Elements Should Be Used To Determine Window Replacement Versus Repair

The Value and Care of Celebrated Windows: Studies + Research

The memory of original windows has always been a high priority in preservation. A renewed emphasis on saving energy is shaping stringent new policies and mandating prescriptive building codes while voluntary ratings are incentivizing tight building envelopes and efficient appliances. Original windows remaining in historic buildings whose maintenance has been neglected over time are first on the listing to be replaced.

Preservationists know that low-tech historic windows that were made to exist durable and easily maintained correspond real energy and resource conservation over time. But where is the quantification of this knowledge to supply the forms required to run across current rating and code thresholds?

Existing window efficiency and repair effectiveness studies take been performed for decades and proceed today. Many studies objectively demonstrate the viability of original window repair. The effort to quantify restored window thermal performance and reduce textile and manufacturing impacts to the environs has made a difference in how the building industry has responded to existing window repair. Retentiveness of historic windows have get incorporated into efficiency ratings and building codes. Existing areas of qualified celebrated buildings to remain are exempt from energy codes. Building codes include a "operation" method for assay of the overall thermal performance of the building envelope, as opposed to the "prescription" method that requires the functioning of each private function to meet specific standards.

All the studies listted here examine the examination results of original window repair and other conservation strategies with new window replacement to compare energy efficiency and impacts on the surroundings.

xiii Things to Know About Retrofitting Celebrated Windows

JuliaRocchi discusses how historic windows ofttimes get the arraign for a edifice's energy loss in this commodity from the National Trust. In it, Ms. Rocchi identifies issues and goals that consumers should consider when determining how to repair therir windows.The article includes a slide show, which is shared here .

Ms. Rocchi also promotes the National Trust report from the Preservation Green Lab in Seattle, "Saving Windows, Saving Money: Evaluating the Energy Operation of Window Retrofit and Replacement" (reviewed below) which is as well useful when planning historic window repair.

National Trust for Historic Preservation Window Evaluation

A study produced by the National Trust for Celebrated Preservation Green Lab provides cost guidance for homeowners weighing the financial and energy tradeoffs between replacing or repairing older, less efficient windows. This report, "Saving Windows, Saving Coin: Evaluating the Energy Performance of Window Retrofit and Replacement", builds on previous research by examining multiple window improvement options, comparing them to replacement windows across multiple climate regions.

Report cover of Saving Windows, Saving Money Primal findings offer homeowners, contractors, architects and others with compelling testify of the merits of retrofitting windows as opposed to outright replacement:

Retrofit measures can achieve performance results comparable to new replacement windows. This report shows that there are readily available retrofit measures that can achieve free energy savings close to new, high operation replacement windows when the operation for each upgrade option is taken into account.
About every retrofit option Offers a better Return on Investment (ROI) than replacement windows. Findings from the cost analysis showed that new, loftier functioning windows are by far the most expensive measure, costing at least double that of common retrofit options when considering materials, installation and full general construction unremarkably required for an existing habitation. In all climate zones analyzed, cellular shades, interior storm panels and various outside storm window configurations offer a college average return on investment compared to new, efficient replacement windows.
The Bottom Line. Retrofitting windows with high performance enhancements can result in substantial energy savings across a variety of climate zones. Selecting options that retain and retrofit existing windows are the nigh toll effective manner to achieve these energy savings and to lower a home's carbon footprint. Retrofits extend the life of existing windows, avoid production of new materials, reduce waste matter and preserve a habitation's grapheme.

Window Preservation Standards Collaborative

In the Autumn of 2010, the pinnacle preservation trades people in North America and Europe met for the International Preservation Trades Workshop in Frankfort, Kentucky. Five window experts, Duffy Hoffman, John Leeke, Jim Turner, David Gibney and Bob Yapp met and decided it was time to create national standards for the repair and weatherization of onetime and historic windows. TheWINDOW PRESERVATION STANDARDS COLLABORATIVE was conceived.

Using cut-edge window testing technology, the Collaborative's tests are verifying "what most people in historic preservation have known for years, old and historic windows can cost effectively be made as or more energy efficient than new, disposable replacement windows." The Collaborative recently published a manual for the assessment and preservation of historic wood windows, reviewed below.

"Window Preservation Standards" Available

The national Window Preservation Standards book catalogs specific methods for the assessment, maintenance, repair, preservation and weatherization of older and historic wooden windows. Many detailed methods, procedures and materials are included, as well as basic strategies for saving older and celebrated windows.

Window Preservation Standards book cover The Standards were developed and written by more than 100 window specialists who collaborated from all beyond the U.s. and Canada.

Topics include the Window Preservation Standards Collaborative, guiding principles for window preservation piece of work, window part names and definitions, organizing and planning window preservation projects, and how to utilize the Standards.

Methods include surveying and assessing conditions, glazing, painting, wood repairs, weatherization updates, storm windows and maintenance with many more than. Each treatment standard has a brief description of a specific method with appropriate employ, a step-by-step procedure that shows what is washed and materials are listed. A special department describes how to judge the graphic symbol of the completed work with easy observations and simple tests to assure the best quality work.

The results of free energy performance testing done at the 2022 National Window Preservation Elevation are included. It confirms what is already known: Save the primary sash and frame, add weatherstripping and a storm to make the window run into or exceed current performance standards for air infiltration. All the details are in the book, including which energy upgrade methods worked all-time.

The Window Preservation Standards book is a not-profit projection done in partnership with the Preservation Trades Network, Kentucky Heritage Quango and Kentucky Preservation. Ordering information tin can exist establish hither.

Window Repair and Retrofit Studies

"Window Repair, Rehabilitation and Replacement" , Peter Bakery, P.E.

This report was prepared for Building America, Building Technologies Plan, Function of Energy Efficiency and Renewable Energy, U.South. Section of Energy to evaluate advanced retrofit measures. A balanced approach is presented to guide contractors and homeowners to decide whether to repair or supplant considering many factors, one of which is historic preservation. November 2022

"A Comparative Written report of the Cumulative Energy Apply of Historical Versus Gimmicky Windows" By Frank Shirley, AIA, Fred Gamble, PhD, Jarod Galvin, RA, LEED AP

This study compares the life-bike costs of two residential window systems in a pre-1940 house in Boston, Massachusetts. One is an original double-hung window with a new triple-rail storm unit. The other is a new, vinyl, double-hung replacement window. Results are obtained from an algorithm that yields the total nowadays value of all costs associated with a window system over its entire life, including acquisition, installation, maintenance, and energy. Dec 2010

"Field Evaluation of Depression-E Tempest Windows" Past S. Craig Drumheller- NAHB Research Center, Christian Kohler- Lawrence Berkeley National Laboratory, Stefanie Minen-Utilivate Technologies

A field evaluation comparison the operation of low emittance (low-e) tempest windows with both standard clear storm windows and no storm windows was performed in a common cold climate. Vi homes with single pane windows were monitored over the menstruum of one heating season. The homes were monitored with no storm windows and with new storm windows. Simple paybacks for the addition of the storm windows were ten years for the clear glass and four.v years for the depression-east tempest windows. December 2007

"The Effects of Energy Efficiency Treatments on Historic Windows" past Larry Kinney and Amy Ellsworth January 2022

This report focused on empirical testing of the energy efficiency and economy of a range of options for upgrading the energy operation of historic windows. The study involved retrofitting windows in a exam home in a historic district in Boulder, Colorado. It included testing in a window laboratory facility adult for the written report.

"Thermal Performance of Traditional Windows" by Dr. Paul Baker for Historic Scotland Revised September 2010

Technical Newspaper 1 tested the employ of curtains, shutters, blinds, and secondary glazing. All were shown to reduce the heat loss through the glazing to varying degrees. Secondary glazing was institute to be the most constructive overall option, every bit it reduced rut loss through the window past 63%. Timber shutters are the nigh effective option of the traditional methods, reducing heat loss by 51%; defunction reduced heat loss by 14%; a Victorian roller blind reduced heat loss by 28%; a modernistic roller blind reduced heat loss past 22%. The greatest reductions in rut loss came from combining these measures (i.due east. blinds, shutters and curtains all closed) and past adding extra insulation to these options.

"Slim-profile double-glazing in listed buildings: Re-measuring the thermal performance" past Nicholas Heath & Paul Baker, Historic Scotland 2022

Technical Report 23 assesses the effectiveness of two inexpensive and minimally invasive methods for improving the thermal operation of single glazed windows. This technical paper demonstrates that a range of options, including minimally invasive and inexpensive methods, can play a worthwhile role in the overall thermal improvement of buildings.

"Of Paint and Windows - Replace or Repair"by Bob Yapp

Bob Yap Blogs Main craftsman Bob Yapp writes nearly all things restoring windows.

"Thermal Performance of Celebrated Windows" past Chris Wood, www.buildingconservation.com (England)

"Edifice Regulations and Historic Buildings: balancing the needs for free energy conservation with those of building conservation"The English Heritage Interim Guidance article touches on all parts of preservation and conservation of power and fuel, and the chapter on windows is very relevant.

"Repair or Supervene upon Windows in Historic Buildings: Arriving at a Sustainable Solution" The Heritage Canada file contains two articles, one from Andrew Powter and Craig Sims discussing how to arrive at a decision to supervene upon or repair original windows, and Susan Turner explains the sustainable nature of window repair rather than replacement.

"The Effects of Energy Efficiency Treatments on Historic Windows" is an empirical study recently completed past the Middle for Resource Conservation in Boulder Colorado. The report involved retrofitting windows in a test home in a historic district and investigated and so compared the energy efficiency and economic system of eleven different preservation treatment options with that of new vinyl windows. Most of the proposed treatments were able to outperform a new vinyl window.

"Life Cycle Of Window Materials - A Comparative Cess" by Asif, Davidson and Muneer. A comparative life cycle assessment of the environmental touch of different window materials is included for its interesting materials energy toll assay.

"Domestic Retrofitting Strategies in the U.k.: Effectiveness vs. Affordability" is an interesting presentation of the effectiveness of dissimilar energy retrofitting strategies, including shutters.

"What Replacement Windows Can't Replace: The Real Cost of Replacing Historic Windows" Walter Sedovic and Jill Gotthelf provide an excellent give-and-take of the comparative value of window replacement versus repair. Many aspects of sustainability are considered.

"Testing the energy functioning of forest windows in Cold Climates" by Brad James, Andrew Shapiro, Steve Flemish region and Dr. David Hemenway is a thoroughly researched paper that concludes that historic windows should not be replaced for energy considerations alone, every bit retrofitted and replacement windows perform similarly.

"Lincoln Hall Windows Research Written report: A Case Written report of Options for Treatment for Windows at Lincoln Hall, University Of Illinois, Urbana Champaign" This report provides empirical data to assess window repair or replacement options for a proposed LEED Gold project, addressing the existing windows in terms of energy consumption.

Window Replacements in the Media