Delaware, Licking and Fairfield County houses, by the numbers

Three counties sit beside Franklin County, and their houses are not one stock but three. This page sets out what the Census Bureau has counted in Delaware, Licking and Fairfield counties since 1940, what its American Community Survey estimates now, and what each county auditor's own parcel record holds, with the table, the year and the universe named in every sentence. It says which figures are complete counts and which are five-year survey estimates, because those are different measurements and are never run as one series here. It carries no prices, and says nothing about any one house.

Last updated September 2026 · The Census Bureau's decennial volumes, its 2020 to 2024 American Community Survey tables and its Building Permits Survey files, the Ohio Department of Development's 2025 county profiles, the Ohio Board of Building Standards' certification list and the three county auditors' own parcel records as downloaded on September 7, 2026 were read September 2026 · No prices on this page; the Estimate Builder carries those · Part of the knowledge base

What this page counts, and what it does not

Delaware County lies north of Franklin County, Licking County east and Fairfield County southeast, and their houses come out of three record keepers: the Census Bureau, for the decennial counts, the American Community Survey and the Building Permits Survey; the Ohio Department of Development's Office of Research, for the county profiles and the state's population table; and the Ohio Board of Building Standards, for the certified residential building departments. Every figure below names its publisher, because none has a second one: a state agency reprinting the Bureau's counts is that count read twice.

Two kinds of measurement run through the page and they are never mixed. A decennial census count is complete and carries no margin of error; an American Community Survey five-year estimate carries one on every line. The Bureau's estimate that 4,365 Delaware County housing units were built in 2020 or later, table B25034 at the 2020 to 2024 vintage, carries a margin of plus or minus 547; its 2020 census count of 81,854 housing units there carries none. The Ohio Department of Development's 2025 county profiles print survey housing figures without naming the survey or its vintage, and those are the 2019 to 2023 estimates: the Delaware profile's year-built block totals 84,215 housing units where the Bureau's 2020 to 2024 file gives 86,269.

Not here: prices or values of any kind, or anything about one house. Water and sewer belong to the places rather than the counties, and this site holds those histories for the city of Delaware, Dublin, Westerville and Gahanna.

Three counties, 1940 to 2020

The Census Bureau counted 8,072 housing units in Delaware County in 1940 and 81,854 in 2020, 10.1 times as many; 19,818 in Licking County and 72,709, 3.7 times as many; and 14,572 in Fairfield County and 62,466, 4.3 times as many. Those are decennial counts of housing units, 1940 from the Bureau's 1990 volume for Ohio and 2020 from its 2020 census redistricting file. Delaware County's is recent growth: the Ohio Department of Development's reprint of the census series gives it 27,381 people in 1880 and 26,780 sixty years later in 1940, and the 2020 census counted 214,124.

Since 1990 the three have not grown alike. Between the 1990 and 2020 censuses Delaware County added 57,477 housing units on the Bureau's counts, Fairfield County 23,452 and Licking County 22,677. In the Ohio Department of Development's table of population counts and estimates, Delaware County's change from 2010 to 2020 was 22.9 percent, which that table ranks first among Ohio's counties, with Fairfield fifth at 8.7 percent and Licking sixth at 7.2 percent. The rank is that agency's own; the Census Bureau publishes no release naming any Ohio county the state's fastest growing.

One caution about that table: its own note says many 2020 figures have been revised, so its 2020 column is not the census count. And 2000 is left out of the series above, because three different figures for each county are in print: the count as first published, the Bureau's revised count in its 2010 volume, and a third in the state's indicators table.

When the houses were built

The plainest single number is the median year built. In the Census Bureau's table B25035 at the 2020 to 2024 American Community Survey five-year vintage, universe housing units, it is 2000 in Delaware County, 1984 in Fairfield County and 1980 in Licking County, against 1970 for Ohio. The distribution behind it is table B25034, Year Structure Built, at the same vintage and universe, where the year built is when the building was first constructed and not when it was remodeled.

The newer end of that table separates them again: it puts 61,862 of Delaware County's 86,269 housing units, about 72 percent, in the lines built 1990 or later, while 36,750 of Licking County's 73,273, about half, were built in 1979 or earlier and 29,725 of Fairfield County's 64,036, about 46 percent.

Each county auditor keeps a parcel record of its own, counting houses the office classes as single family rather than housing units. Filtered to the Ohio Administrative Code's six land-use codes for a one-family dwelling, 510 through 515, with a year built on file, the records as downloaded on September 7, 2026 hold 65,039 single-family houses in Delaware County, 53,446 in Licking County and 47,140 in Fairfield County. The count by decade built is the one measure defined the same way in all three, so it is the only one set side by side here.

On that measure Delaware County's houses are the newest: 22.08 percent were built in the 1990s and 27.35 percent in the 2000s. Licking County's are spread more evenly across the decades than Delaware County's: 14.19 percent in the 1990s and 14.18 percent in the 2000s, with 9.01 percent in the 1950s, 11.13 in the 1960s and 11.39 in the 1970s. Fairfield County reads 17.21 percent in the 1990s and 14.17 in the 2000s.

One warning goes with that. All three offices default an unknown year built to a round year, so the 1900s row in each record is mostly houses whose building year the office does not know: 5,489 of Fairfield County's 5,685 houses in that row carry exactly 1900, 2,374 of Delaware County's 2,668 carry 1901 and 1,913 of Licking County's 2,600 carry 1900, which is why no figure for that decade prints here as a count of houses built between 1900 and 1909. The decade built is the hinge of the page on windows and glass in a Central Ohio house by era.

Plumbing, on two universes

The Census Bureau publishes two plumbing tables that answer different questions. Table B25047, Plumbing Facilities for All Housing Units, at the 2020 to 2024 vintage, counts 714 of Delaware County's 86,269 housing units, 1,028 of Licking County's 73,273 and 712 of Fairfield County's 64,036 as lacking complete plumbing facilities: 0.8, 1.4 and 1.1 percent against 2.0 percent for Ohio, with every margin of error a quarter or more of its own estimate. Table B25048 asks the same question of occupied housing units only, at the same vintage, and gives 178, 142 and 131, about 0.2 percent each. The gap is not a disagreement: housing units are occupied units plus vacant units, so the difference between the two counts is the vacant units.

The definition moved as well. In the Bureau's 2024 subject definitions, complete plumbing facilities are hot and cold running water and a bathtub or shower, both inside the unit, and a flush toilet is not part of it. The 1990 census used a different definition, hot and cold piped water, a flush toilet and a bathtub or shower, all three inside the unit, and on that definition its Table 66 for Ohio, universe all housing units, counted 54 in Delaware County, 302 in Licking County and 250 in Fairfield County as lacking them. The two are not one series.

Bathrooms, the last time anybody counted

The 1980 census is the last one that asked how many bathrooms a house had. In the Census Bureau's 1980 detailed housing volume for Ohio, Table 94, universe year-round housing units and estimates based on a sample, 27,365 of Licking County's 44,576 year-round housing units, about 61 percent, had exactly one complete bathroom. Fairfield County read 18,692 of 33,565, about 56 percent, at one and 8,227, about a quarter, at two or more, and Delaware County already stood apart, with 5,197 of its 18,779, about 28 percent, at two or more.

That universe is narrower than the housing unit count of the same census: year-round housing units are all occupied units plus vacant units available or intended for year-round use, so Fairfield County's 33,565 in the bathroom table sits below the 33,883 housing units the 1980 census counted there, and the two must not be subtracted. The state page on bathrooms per house in Ohio carries the Ohio, Columbus and Franklin County lines from the same table.

Since 1980 the only bath counts are the auditors'. In the Fairfield County Auditor's record as downloaded on September 7, 2026, 69.53 percent of the single-family houses carry two or more full baths, 28.45 percent of the 1950s houses and 91.62 percent of the 1990s ones; the office prints that field on its own parcel report against the label Number of Full Baths, and no document says whether it counts rooms or fixture groups. In the Delaware County Auditor's record downloaded the same day, 88.91 percent carry two or more, 32.32 percent of the 1950s houses and 97.66 percent of the 1990s ones, on a field nothing the county publishes defines. The two fields are not known to count the same thing, which is why they stay in separate sentences; Licking County's published record has no bath field at all.

How the houses are heated

House heating fuel is table B25040, universe occupied housing units. At the 2020 to 2024 vintage the Census Bureau puts 55,636 of Delaware County's 82,287 occupied housing units, about 68 percent, on utility gas and 20,023, about a quarter, on electricity; Licking County reads 44,874 of 68,620 on utility gas, about 65 percent, and Fairfield County 36,110 of 60,357, about 60 percent. What separates the three from Franklin County is the bottled line: at the same table and universe, bottled or tank gas heats 8.4 percent of Licking County's occupied homes, 7.5 percent of Fairfield County's and 5.8 percent of Delaware County's, against 1.5 percent in Franklin County. Coal has all but gone: the coal or coke line reads zero occupied homes in Delaware and Fairfield counties and one in Licking County, and those zeros carry a margin of plus or minus 30, which means the survey found none in its sample rather than that none exists. Where that coal came from is the subject of the page on the Hocking Valley coal towns that heated Columbus, and the heating page holds the Franklin County series.

Only one of the three auditors records a fuel. The Fairfield County Auditor's September 7, 2026 download ships the office's own field-value dictionary inside it, and against that dictionary 77.98 percent of the county's single-family houses carry the fuel value labeled gas and 16.48 percent the one labeled electric. The electric value peaks among houses built in the 1970s at 58.62 percent, a decade in which gas falls to 35.01 percent, and gas is back to 94.25 percent among houses built in the 2020s. Delaware County's heating field has two values, one on 99.89 percent of its houses, and Licking County's record has none.

How they are held, and what they are

At the 2020 to 2024 five-year vintage the Census Bureau's tenure table, B25003, universe occupied housing units, puts 78.5 percent of Delaware County's occupied homes, 74.9 percent of Fairfield County's and 73.7 percent of Licking County's in owner occupancy, against 52.8 percent in Franklin County. Table B25024, Units in Structure, universe housing units, puts one-unit detached houses at 78.7 percent of Fairfield County's stock, 76.0 percent of Licking County's and 74.3 percent of Delaware County's, against 52.0 percent in Franklin County, and counts 3,502 mobile homes in Licking County.

Size splits them as sharply as age does. In table B25041, Bedrooms, at that same vintage, universe housing units, 36,814 of Delaware County's 86,269 housing units, about 43 percent, have four or more bedrooms, against about 30 percent in Fairfield County and about 26 percent in Licking County; in table B25017, Rooms, at the same vintage, 26,943 of Delaware County's units, about 31 percent, have nine or more rooms, against about 20 percent in Fairfield County and 17 percent in Licking County. A room in those tables is never a bathroom: the Bureau's subject definitions exclude bathrooms from the room count.

New houses authorized, and who enforces the code

The Census Bureau's Building Permits Survey counts a permit and not a house. The Bureau describes it as statistics on new privately-owned residential construction, and its county file carries totals only for the counties whose permit offices are requested to report. In its annual files, Delaware County places authorized 1,979 one-unit buildings in 2024 against 852 in 2015, and never fewer than 1,144 in any year since 2016, while Licking County places authorized fewer in each year after 2021: 361 in 2021, 268 in 2022, 174 in 2023 and 156 in 2024. Fairfield County's latest figure needs a caveat of its own: of the 452 one-unit buildings the survey reports there for 2024, only 196 came from permit-issuing places and the rest were imputed.

Which department enforces the residential code differs too. On the Ohio Board of Building Standards' Residential Building Department Certification List, whose pages are stamped August 16, 2023, Delaware County holds a certified residential building department, with five sub-departments under it, and Licking County one with ten. Fairfield County has no county entry on that list, and its own building department says it does not regulate one-, two- and three-family structures. Its municipal section carries Lancaster, which the Ohio Department of Development's 2025 profile gives as the Fairfield County seat, along with Pickerington and Baltimore, so a place inside that county can have a certified residential department of its own even though the county does not. The list is a certification record: it says which departments are certified, not which one reviewed any house, and nothing about the parts of a county outside one. The page on which building code a Central Ohio house was built under holds the rest.

Where this touches a bathroom

The decade a house was built is the only thing in these tables that speaks to its bathrooms, and it speaks through two records that do not share a definition: the 1980 census count on a year-round universe, and two auditors' undefined full-bath fields, each describing the house as the office has it today rather than as it was built. The state series and the Bureau's bathroom definitions are on the bathrooms per house page, and Franklin County's auditor series on the Central Ohio bathroom page.

What this page cannot say

Every auditor figure above comes from a valuation record, current as of whenever the office last reviewed the parcel, so it describes the house as the office has it now: a house recorded as built in 1925 with two full baths has two full baths on file today, and nothing says what it was built with. None of the three records says what equipment is behind a heat or fuel value, or whether the wiring, the plumbing or the insulation has ever been changed. And nothing here is about any one house: no parcel record was opened to write it.

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.

• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table-based summary file, table B25034 Year Structure Built (acsdt5y2024-b25034.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year table-based summary file, table shells (ACS20245YR_Table_Shells.txt), 2024 vintage, released 2025; read September 2026.
• U.S. Census Bureau, 2020 Census Redistricting Data (P.L. 94-171) Summary File, Ohio, geographic header file, 2021; read September 2026.
• Ohio Department of Development, Office of Research, Ohio County Profiles, 2025 Edition: Delaware County, 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2019-2023 five-year estimates, table B25034 Year Structure Built (acsdt5y2023-b25034.dat), 2024; read September 2026.
• U.S. Census Bureau, 1990 Census of Population and Housing, Population and Housing Unit Counts, Ohio (1990 CPH-2-37), Table 3, Population and Housing Units: 1940 to 1990, undated; read September 2026.
• Ohio Department of Development, Office of Research, Ohio County Indicators, Table 1: Population Counts and Estimates, 2000-2024, May 2025; read September 2026.
• U.S. Census Bureau, 2010 Census, Population and Housing Unit Counts, Ohio (CPH-2-37), Table 4, Population and Housing Units: 1970 to 2010, August 2012; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25035 Median Year Structure Built (acsdt5y2024-b25035.dat), 2025; read September 2026.
• Ohio Laws and Administrative Rules (codes.ohio.gov), Ohio Administrative Code, rule 5703-25-10, Classification of real property, undated; read September 2026.
• Delaware County Auditor's GIS Office, Parcel: Delaware County GIS Data Hub dataset and CSV export, August 28, 2026; read September 2026.
• Licking County Auditor, Parcels feature service, Auditor folder (field list and record count), July 10, 2026; read September 2026.
• Fairfield County Auditor, Fairfield County CAMA and Layout Download (extract job AA407), including the office code tables and the field-value dictionary AEDIT.DAT, August 20, 2026; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25047 Plumbing Facilities for All Housing Units (acsdt5y2024-b25047.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25048 Plumbing Facilities for Occupied Housing Units (acsdt5y2024-b25048.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey and Puerto Rico Community Survey 2024 Subject Definitions, 2025; read September 2026.
• U.S. Census Bureau, 1990 Census of Housing, Detailed Housing Characteristics: Ohio (CH-2-37), Table 66, Structural Characteristics: 1990, undated; read September 2026.
• U.S. Census Bureau, 1980 Census of Housing, Volume 1, Chapter B, Detailed Housing Characteristics: Ohio (HC80-1-B37), Table 94, Equipment and Plumbing Facilities for Counties: 1980, July 1983; read September 2026.
• Fairfield County Auditor, Public parcel report, Dwelling Characteristics table (the labels the office prints beside its own field values), undated; read September 2026.
• Delaware County Auditor's GIS Office, Parcel feature service (field list and record count), undated; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25040 House Heating Fuel (acsdt5y2024-b25040.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25003 Tenure (acsdt5y2024-b25003.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25024 Units in Structure (acsdt5y2024-b25024.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25041 Bedrooms (acsdt5y2024-b25041.dat), 2025; read September 2026.
• U.S. Census Bureau, American Community Survey 2020-2024 five-year estimates, table B25017 Rooms (acsdt5y2024-b25017.dat), 2025; read September 2026.
• U.S. Census Bureau, Building Permits Survey, county annual data files 2015 to 2024 (co2015a.txt to co2024a.txt), 2025; read September 2026.
• U.S. Census Bureau, Building Permits Survey program page, undated; read September 2026.
• U.S. Census Bureau, Residential Building Permits Survey Documentation: County ASCII Files, February 9, 2022; read September 2026.
• Ohio Board of Building Standards, Ohio Department of Commerce, Residential Building Department Certification List, pages stamped August 16, 2023; read September 2026.
• Ohio Department of Development, Office of Research, Ohio County Profiles, 2025 Edition: Fairfield County, 2025; read September 2026.

Common questions