Windows and glass in a Central Ohio house, era by era, and the rules a window meets today

A window is a frame, a sash, glass and hardware, and each changed on its own schedule. This page reads those eras from the documents that date them, each labeled with the geography it covers: the National Park Service's briefs describe the country, the Energy Information Administration counts the country and a five-state census division, and only the code is Ohio's. Nothing measures what windows a Central Ohio house actually has, so no share is given for one. What is exact is what the rules ask of a window now, in the Residential Code of Ohio's own section numbers and in the federal glazing standard's own words.

Last updated September 2026 · National Park Service preservation briefs, the Residential Code of Ohio's own rule text, the federal glazing standard, a 1936 patent, two Ohio Historical Markers, two Columbus city directories and the 2020 Residential Energy Consumption Survey were read September 2026 · No prices on this page; the Estimate Builder carries those · Part of the knowledge base

What a window is, and how this page reads the eras

Almost every dated statement below is national, because the documents that date it are national: the National Park Service's preservation briefs describe American buildings, the safety glazing standard is federal, and the Energy Information Administration counts windows for the country and for a five-state census division. Only the code is Ohio's.

Nothing measures what windows a Central Ohio house has. The Franklin County Auditor's dwelling extract carries 44 columns, among them style, stories, exterior wall, heat and year built, and not one names a window or its glazing. The Census Bureau's Characteristics of New Housing carries no window item either. What a window can and cannot tell about a house's age, including the Park Service's warning that sash styles associate with periods only on a site-specific, regionally oriented basis, is on the era and style page.

The wooden sash and its parts

The National Park Service says the first windows in early American houses were casement windows, hinged at the side and opening outward, and that single- and double-hung windows were introduced at the beginning of the eighteenth century. That is Preservation Brief 9, published in 1981 and national.

The same brief names the parts. The lower sash comes out once the interior stop is off; the upper sash is held by a parting bead set into a groove in the center of the stile; and the sash cords run over pulleys to weights in a pocket the Park Service says is frequently accessible through a door on the face of the frame near the sill. It calls replacing those cords with new rope cords or with chains one of the most common work items on a wooden window frame. Ohio adds vocabulary rather than dates: the state's own inventory manual names double-hung sash by their lights, one over one to twelve over twelve, and that language is on the era and style page.

The steel window, 1890 to 1950

The National Park Service says historic steel windows dominated the metal window market from 1890 to 1950, the span of its Preservation Brief 13, published in 1984 and national. Metal windows were available as early as 1860 from catalogs published by architectural supply firms, it says, but did not become popular until after 1890, because technology borrowed from the rolling industry allowed mass production and a series of urban fires led to strict fire codes for industrial and multi-story commercial and office buildings. Rolled sections made the sash, the frame and the subframe alike, and with wire glass added a fire-resistant window resulted; the brief says these windows are found almost exclusively in masonry or concrete buildings.

Rolled steel casements were popular in the 1920s for cottage style residences and Gothic style campus architecture, the Park Service says, and more streamlined ones in the 1930s for institutional and small industrial buildings; Ohio's own dating of Tudor and English Revival casements, about 1910 to 1940, is on the era and style page. The Park Service says metal double-hung windows were early examples of a building product adapted to meet stringent new fire code requirements for manufacturing and high-rise buildings in urban areas, and that, soon supplanted in industrial buildings by less expensive pivot windows, they regained popularity in the 1940s for use in speculative suburban housing; the brief does not say where.

Rolled steel stayed in extensive use until after the Second World War, the Park Service says, when cheaper, non-corroding aluminum windows became increasingly popular; it recorded aluminum as dominating the market in 1984, the year it published the brief.

Ohio's glass towns, and Columbus's sash mills

Ohio made window glass, and two Ohio Historical Markers say where. The marker in Findlay, in northwest Ohio, credits the gas boom that began with the town's first natural gas well in 1884 and the Great Karg Well of 1886 with drawing eight window glass factories there, among other glass works; the marker in Fostoria, in Seneca County, says more than a dozen companies made glass there between 1887 and 1920, windows among their products. Both towns are northwest Ohio, not Central Ohio. Toledo's plate and sheet glass is on the page on what Ohio made for houses, and what heated Columbus itself is on the Hocking Valley page and the heating page.

Columbus milled its own sash and doors. The Columbus city directory G. J. Brand and Co. published for 1879 carried a classified heading for sash, door and blind manufacturers with nine firms listed under it, five of them on or at the corner of Water and Spring streets by the river; the directory R. L. Polk and Co. published for 1913 still carried headings for sash, doors and blinds, but the firms under them were by then lumber and supply companies. Both are trade directories, which is why both publishers are named and why the nine is a count of listings.

Insulating glass, glass block and coatings

Insulating glass has a primary record: United States Patent 2,030,869, for a multi-ply glass sheet glazing unit, applied for on October 12, 1934 and granted on February 18, 1936 to Charles D. Haven of Milwaukee. As printed by the United States Patent and Trademark Office it names the assignee as The Thermopane Company of Toledo, Ohio, a corporation of Ohio, and says the product had already been manufactured and sold commercially by that company under the trade name Thermopane. Toledo is northwest Ohio, and the record does not say how or when the product later passed to another company.

The Owens-Illinois Glass Company sold glass block as Insulux, and the Smithsonian Libraries and Archives holds the company's own sales literature for it, dated from 1937 and including a 1939 piece addressed to the home. Ohio's residential code still carries Section 607 for glass unit masonry: hollow units partially evacuated, with a minimum average glass face thickness of three-sixteenths of an inch; a standard unit not less than three and seven-eighths inches thick; an interior standard-unit panel no larger than 250 square feet; and the use of reclaimed units, which the code prohibits. Ohio also excepts glass unit masonry built to Section 607 from the human impact load test other glazing must pass, and its energy chapter gives glazed block a default U-factor of 0.60 where the product carries no rated label.

Lawrence Berkeley National Laboratory says low-emissivity coatings had been around since the Second World War in specialty applications such as oven windows, and that federal funding after the energy crisis of the early 1970s went into whether the same technology could make building windows more efficient. It dates the first commercial low-emissivity product to 1981, a transparent film installed between the panes of a multi-pane window, and says that by 1988, 20 percent of all windows sold in the United States carried such a coating.

Frames, panes and the storm window

The Energy Information Administration's 2020 Residential Energy Consumption Survey put double-pane glass in 77.95 million American homes, single-pane in 43.51 million and triple-pane in 2.07 million, out of 123.53 million primary occupied homes; it recorded frame material as metal or aluminum in 47.40 million homes, wood in 40.31 million and vinyl in 31.85 million, with composite and fiberglass behind them.

The region inverts part of that. In the East North Central census division, the five-state group of Ohio, Indiana, Illinois, Michigan and Wisconsin, the same survey put single-pane glass in 5.77 million homes, double-pane in 12.43 million and triple-pane in 350,000, out of 18.55 million homes, and found wood the commonest window frame material there, in 7.47 million homes, ahead of vinyl at 5.79 million and metal or aluminum at 4.62 million. Wood leads regionally where metal leads nationally. Neither is an Ohio figure: five states is the smallest geography the survey publishes that contains Ohio.

Vinyl has no arrival date in this record. The earliest federal mention found is a list: by 1981 the National Park Service was naming vinyl among the materials a storm window frame could be made of, alongside wood, aluminum and plastic. That is a date by which vinyl existed in ordinary use, in a passage about storm windows, not a date of arrival.

The storm window has a measured figure. The Park Service says a single-glazed storm window may only raise a single-pane window's thermal resistance to R2, twice that of the single-glazed window alone, and that clear, non-tinted, low-emissivity glass in the storm window raises it further; that is from its 2011 brief on energy efficiency in historic buildings, which is national. The same agency's older pair of U-values for a single-glazed wooden window is on the page on how Central Ohio houses were built.

One more figure carries two dates. Preservation Brief 9 of 1981 cites the 1977 ASHRAE Fundamentals for its window U-values and puts a double-glazed metal window with no thermal break at about 0.6, worse than the 0.44 to 0.49 the same passage gives a single-glazed wooden window with a storm window added. Both dates belong to that figure: it is 1977 engineering quoted in a 1981 federal brief, not a window sold now.

What the rules ask of a window today

Ohio prints its residential sections without the model code's R prefix, so a plan review here says 308.4, not R308.4. The rules holding the window sections took effect on July 1, 2019, and each prints its own earlier dates, chapter 3 running back to May 27, 2006 and the energy chapter to January 1, 2008. Which edition a given house was built under is settled by a plan approval rather than by a year, and the page on which code a house was built under owns that; how Columbus came to inspect what is built is on the page on the city's inspection offices.

Ohio names seven hazardous locations for glazing, in Sections 308.4.1 through 308.4.7: in doors; next to doors; in large windows near a walking surface; in guards and railings; at wet surfaces; next to stairs and ramps; and next to the bottom stair landing. Section 308.4.3, the large-window rule, catches a postwar picture window: a pane larger than 9 square feet whose bottom edge is under 18 inches above the floor and whose top edge is over 36 inches, with a walking surface within 36 inches of it. The era and style page carries the picture window as a feature of the Ohio ranch.

Ohio sends the test itself to the federal standard, and asks in Section 308.1 that every pane in a hazardous location carry a manufacturer's designation, visible in the final installation, naming who applied it, the type of glass and the safety glazing standard it meets, acid etched, sandblasted, ceramic-fired, laser etched or embossed. That is the small mark in the corner of a shower panel.

Ohio's energy table puts every Central Ohio county in climate zone 5A, Franklin, Delaware, Licking, Fairfield, Madison, Union, Pickaway, Morrow and Knox among them, and caps a new house's skylight U-factor there at 0.55 while asking nothing at all of the solar heat gain coefficient. The window U-factor for that zone is on the page on how Central Ohio houses were built, and the three counties beside Franklin are on the counties page.

The federal safety glazing standard

The Consumer Product Safety Commission issued the Safety Standard for Architectural Glazing Materials on January 6, 1977; it took effect on July 6, 1977, with a later date of January 6, 1980 for glazing in assemblies meant to retard the passage of fire. Codified at 16 CFR part 1201, it covers glazing in five architectural products: storm doors or combination doors, doors both exterior and interior, bathtub doors and enclosures, shower doors and enclosures, and sliding glass doors of the patio type. An ordinary window is not on that list, and Ohio's hazardous-location sections are what reach one.

Shower doors and enclosures and bathtub doors and enclosures are Category II products under that standard, the heavier of its two impact classes. The Commission amended the standard on March 23, 2016, replacing its own 1977 test procedures with those of the voluntary standard ANSI Z97.1-2015; no document read for this page gives that amendment an effective date. The Commission also defines the two kinds of glass a modern bathroom is glazed with: tempered glass is specially heat treated or chemically treated glass that cannot be cut, drilled, ground or polished after treatment without fracture. What tempered glass means for a shower door is on the shower doors and glass page.

A window in a bathroom, and what the record does not settle

Paint on an old window is a hazards subject rather than a window one: what the federal renovation rule says about window work is on the lead paint and asbestos page, with the rest of the house's hazards on the page on what goes wrong in a Central Ohio house.

A window at a tub or shower meets Ohio's wet-surface rule. Section 308.4.5 counts glazing in walls, enclosures or fences containing or facing hot tubs, spas, whirlpools, saunas, steam rooms, bathtubs, showers and swimming pools as a hazardous location where its bottom exposed edge is less than 60 inches above any standing or walking surface; its exception is glazing more than 60 inches, measured horizontally, from the water's edge of the tub or the edge of the shower. Ohio's code treats a bathroom's window and its fan as alternatives, in Section 303.3, which the bathroom electrical page owns; what a fan has to move is on the ventilation page.

The record settles less than a reader might hope. There is no Columbus date for any window material: the two directories show sash and door milling in the city in 1879 and in 1913, and nine listings under an 1879 heading is a count of listings, not a census of operating mills. No local record dates the arrival of the steel casement, the aluminum frame or the vinyl frame in Columbus, and no national date should be read as one.

Sources

Every figure, date and quotation on this page comes from one of these documents, read on the date given. Where two of them disagree, the page says so.

• Franklin County Auditor, Outside User Files: 2026-08-15 Appraisal, Tab-Delimited (Dwelling.txt), column header row, undated; read September 2026.
• U.S. Census Bureau, Characteristics of New Housing, current annual characteristics tables (2025 data), July 1, 2026; read September 2026.
• National Park Service, U.S. Department of the Interior, Preservation Briefs 9: The Repair of Historic Wooden Windows, 1981; read September 2026.
• National Park Service, U.S. Department of the Interior, Preservation Briefs (the index page that dates each brief), undated; read September 2026.
• National Park Service, U.S. Department of the Interior, Preservation Briefs 13: The Repair and Thermal Upgrading of Historic Steel Windows, 1984; read September 2026.
• Ohio Historical Marker program, Ohio History Connection, Marker 21-32, The Glass Industry of Findlay (Hancock County), undated; read September 2026.
• Ohio Historical Marker program, Ohio History Connection, Marker 5-74, Fostoria, Ohio - Home of Fostoria Glass (Seneca County), undated; read September 2026.
• G. J. Brand and Co., Columbus (read on the Internet Archive), Columbus City Directory for 1879, 1879; read September 2026.
• R. L. Polk and Co. (read on the Internet Archive), Columbus, Ohio City Directory, 1913, 1913; read September 2026.
• United States Patent and Trademark Office, U.S. Patent 2,030,869, Multi-ply glass sheet glazing unit (Charles D. Haven), February 18, 1936; read September 2026.
• National Park Service, U.S. Department of the Interior, Preservation Briefs 3: Improving Energy Efficiency in Historic Buildings, 2011; read September 2026.
• Smithsonian Libraries and Archives, [Collected sales literature on Insulux glass blocks], Owens-Illinois Glass Company, 1937; read September 2026.
• Ohio Board of Building Standards (Residential Code of Ohio, at codes.ohio.gov), Ohio Administrative Code rule 4101:8-6-01, Wall construction (Section 607, Glass Unit Masonry), effective July 1, 2019; read September 2026.
• Ohio Board of Building Standards (Residential Code of Ohio, at codes.ohio.gov), Ohio Administrative Code rule 4101:8-3-01, Building planning, effective July 1, 2019; read September 2026.
• Ohio Board of Building Standards (Residential Code of Ohio, at codes.ohio.gov), Ohio Administrative Code rule 4101:8-11-01, Energy efficiency, effective July 1, 2019; read September 2026.
• Lawrence Berkeley National Laboratory, Building Technology and Urban Systems (U.S. Department of Energy), Low-e Windows and Five Decades of Development, undated; read September 2026.
• U.S. Energy Information Administration, 2020 Residential Energy Consumption Survey, Table HC2.7, Structural and geographic characteristics of homes in the Northeast and Midwest regions, March 2023; read September 2026.
• Ohio Board of Building Standards (Residential Code of Ohio, at codes.ohio.gov), Ohio Administrative Code rule 4101:8-1-01, Administration, effective July 1, 2019; read September 2026.
• Office of the Federal Register, National Archives and Records Administration (eCFR), 16 CFR Part 1201, Safety Standard for Architectural Glazing Materials, January 6, 1977, as amended through March 23, 2016; read September 2026.
• U.S. Consumer Product Safety Commission, Final Rule to Amend the Safety Standard for Architectural Glazing Materials, March 2016; read September 2026.

Common questions