For more information, call or write:Oak Park Historic Preservation CommissionCommunity Planning &

Development Department Village of Oak Park123 Madison StreetOak Park, IL 60302708.358.5417planning@oak-park.us

Visit www.oak-park.us

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This brochure has been financed (in part)with federal funds from the Departmentof the Interior, administered by theIllinois Historic Preservation Agency.However, the contents and opinions donot necessarily reflect the views or poli-cies of the Department of the Interiornor the Illinois Historic Preservation

Agency, nor does the mention of trade names or com-mercial products constitute endorsement or recom-mendation by the Department of the Interior nor theIllinois Historic Preservation Agency.

This program receives Federal financial assistance foridentification and protection of historic propertiesunder Title VI of the Civil Rights Act of 1964, Section504 of the Rehabilitation Act of 1973, and the AgeDiscrimination Act of 1975, as amended, the U. S.Department of the Interior prohibits discrimination onthe basis of race, color, national origin, or disability orage in its federally assisted programs. If you believeyou have been discriminated against in any program,activity, or facility as described above, or if you desirefurther information, please write to:

Office for Equal OpportunityNational Park Service

P. O. Box 37127Washington, D.C. 20013-7127

orEqual Employment Opportunity Officer

Illinois Historic Preservation Agency1 Old State Capitol Plaza

Springfield, IL 62701

Historic Windows How Repair Can Save Money,Preserve Character and ImproveEnergy Efficiency

Simulated divided light windows, which havegrilles permanently applied to the exterior of the glass, offer a good substitute for historic wood muntins. Avoid flat grillesplaced between windowpanes or only on the interior, because they poorly replicate the aesthetic qualities of a historic window.

Summary

One of the basic tenets of preservation is torepair something first, when possible, ratherthan replace. After all, the old windows youmay consider for replacement have beenprotecting your house for up to a century.Most replacement windows, particularly vinylproducts, are only guaranteed for a few years.Preservation experts joke that there is a goodreason they call them “replacement windows”— you have to replace them over and overagain, unlike some historic windows that havelasted 100 years with regular maintenance.

It could take 20 or 30 years to get back inenergy savings what you spend on windowreplacements. Most people just don’t stayin a home long enough to recoup themoney they spent.

Beth Parks, Associate Professor of Physics atColgate University

Why historic windows matter

Windows are significant character-defin-ing elements of historic buildings. Their

design, craftsmanship and aesthetic quali-ties often make them worthy of preservation.People often do not realize that windows domore than let in light and air. The wrong win-dow can stand out like a black eye on an his-toric home. This is especially true when onetype of window is replaced with another type,such as replacing a double-hung for instancewith a casement or sliding window.

Some people decide to replace windowsin pursuit of better energy efficiency, conven-ience and lower maintenance. Most local res-idents have received a telephone call or mailerurging them to consider replacement windowsto make an old home more energy efficientwith less maintenance. These promotionsimply that swapping old wood or metal win-dows with vinyl or aluminum replacementswill automatically save you money in lowerenergy costs.

But like all components of historic build-ings, windows need regular maintenance toextend their useful life. Even if windows are

deteriorated, it can often be cheaper toreglaze, caulk, weather-strip or scrape andpaint the old windows, which are made ofold-growth wood, a denser, longer-lastingmaterial than wood harvested today. Theaddition of a storm window can protect ahome’s historic windows and extend theirlife for decades. Properly maintained historicwood windows with weather-stripping andstorm windows can improve their energyefficiency and are comparable to the energyefficiency of many new windows.

Of course, some window components maybe so rotted or otherwise deteriorated thatreplacement is necessary. In that case, build-ing owners are urged to replace windows orwindow parts as needed with windows thatmatch the style, size and materials of theoriginals.

Under local ordinance, owners of buildingswithin Oak Park’s historic districts, or ofbuildings designated as Historic Landmarksthroughout the Village, are required to getpermits before replacing windows. The Oak

Park Historic Preservation Commission offersfree advice and helpful literature that can guideyou to the best choices for your historic home.

A preservation-friendly approach:Retain, repair, replace.

Try to repair what you have. Investigate thehistoric windows to determine the problemsand their causes. Only after weighing theaesthetic, performance, energy efficiency,cost and long-term durability aspects of pro-posed work can an informed decision bemade whether to repair or replace windows.

If you cannot feasibly repair it, replace itwith the same thing. Consider the impactof the new windows on the appearance ofthe building. Replacement windows shouldmatch the historic windows in their materials,operation and design.

If you cannot replace it with the same thing,replace it with something that is similar inappearance. Wood windows are offered withaluminum or vinyl cladding on the exterior,which helps reduce the maintenance.

Windows only account for up to 10 percent of a building’s energy costs.Insulating your roof will save 80 percentof all energy savings possible. Caulkingthe exterior of the window frames willblock airflows. Reglazing, painting andweather-stripping saves more energy thannew double-glazed windows.

Vince Michael, Director of the Historic PreservationProgram, School of the Art Institute of Chicago

A master plan should becreated for the phasedrepair or replacement ofwindows in apartmentbuildings and condo-miniums. Such a masterplan should identify

existing and proposed conditions, andprovide design standards for systematicfuture repair or replacement work. Avoidthe haphazard replacement of windows inseparate living units.

Oak Park Architectural Review GuidelinesSource: National Trust for Historic Preservation

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