CONDO OWNERSHIP
From Listings to Living
Two condos in the same building are listed at the same price. One says 1,050 square feet, the other 980. When you tour them, the "smaller" one feels larger: wider living room, a real dining nook, less hallway. Then the appraisal on the first unit comes back at 990 square feet, and the price per foot you thought you were paying no longer exists.
So how big is a condo? There is no standard size, but the best national data gives a useful range. The Census Bureau's 2025 figures put the median new multifamily unit built for sale, a group that includes condos and co-ops, at 1,170 square feet. Rental apartments in large buildings average 910 square feet, according to RentCafe's analysis of Yardi Matrix data. Studios run well below those figures and three-bedroom units well above, as the bedroom data below shows.
The more useful answer is that the number depends on how it was measured. Census figures for multifamily buildings include a share of hallways and lobbies, while an appraiser measures an apartment-style condo from the inside of its walls. Knowing which method produced the figure matters as much as the figure itself.
Leevli Editorial Team
No single dataset measures every existing condo in the country. The table shows the dated, sourced figures that come closest, and what each one actually measures.
| Dataset | Figure | What it measures |
|---|---|---|
| Census, new multifamily units built for sale, 2025 | Median 1,170 sq ft; average 1,383 sq ft | Newly completed units for sale as condos or co-ops, based on building square footage divided by units |
| Census, new multifamily units built for rent, 2025 | Median 1,000 sq ft; average 1,044 sq ft | Newly completed rental units, same method |
| RentCafe and Yardi Matrix, published August 2026 | Average 910 sq ft | Apartments in large buildings (50 or more units) tracked by Yardi Matrix |
| Census, new single-family homes completed, 2025 | Median 2,142 sq ft | Finished floor area of new houses, for comparison |
The Census figures come from the Highlights of 2025 Characteristics of New Housing, published July 1, 2026, and the underlying multifamily square footage table. That table's footnotes say units built for sale include condominiums and cooperatives, and may also include buildings sold whole. The for-sale median carries a relative standard error of 16 percent, because only about 23,000 of the 484,000 multifamily units completed in 2025 were built for sale. Treat it as a range, not a precise number.
The Census method inflates the per-unit figure compared with what you will see on an appraisal. Under the Survey of Construction definitions, multifamily square footage covers all finished floor space plus "associated living space," defined as hallways, elevator space, lobbies and any other indoor space used by the residents. The table's footnote adds that the per-unit average is total square feet of all floors, based on exterior dimensions, divided by the number of units. A new condo listed at 1,000 square feet of interior space could easily belong to a building that reports a larger per-unit figure to the Census.
The Census does not publish condo size by bedroom count, but it does publish the bedroom mix. Of the multifamily units built for sale and completed in 2025, 4 percent were efficiencies, 24 percent had one bedroom, 38 percent had two and 35 percent had three or more, according to the Census bedrooms table. Two-bedroom and larger plans make up most of new for-sale construction.
For size by bedroom, the closest dated figures come from rentals. RentCafe's August 2026 report, based on Yardi Matrix data for buildings with 50 or more units, lists these national averages:
| Unit type | Average size (RentCafe, 2026 report) |
|---|---|
| Studio | 460 sq ft |
| One bedroom | 735 sq ft |
| Two bedrooms | 1,095 sq ft |
| Three bedrooms | 1,355 sq ft |
| All units | 910 sq ft |
Condo floor plans in a given building may run larger or smaller than these averages, so use them as a reference for what a bedroom count typically buys, not as a promise. Studios are covered in depth in what a studio apartment is, including the building code minimums for an efficiency unit.
The Census size distribution shows how wide the range is. Of the multifamily units built for sale and completed in 2025, 32 percent were in buildings averaging under 1,000 square feet per unit, 18 percent fell between 1,000 and 1,199, 11 percent between 1,200 and 1,399, 12 percent between 1,400 and 1,799, and 27 percent averaged 1,800 square feet or more. That is a market with plenty of compact units and a large block of very large ones, not a single typical size.
Region matters too. The Census put the 2025 median for-sale unit at 932 square feet in the Northeast and 1,538 in the South, though both estimates carry wide error margins.
City-level data from RentCafe points the same way for newer rentals. Among apartments built from 2016 to 2025, Seattle had the smallest average at 645 square feet, followed by Portland at 665, and Brooklyn (714) and San Francisco (717) also ranked among the five smallest. If you are touring newer buildings in Seattle, from Ballard to downtown, or in Portland's Pearl District, the citywide averages suggest compact plans. The same applies to newer buildings anywhere in Brooklyn, Brooklyn Heights included. At the other end, Tallahassee led at 1,156 square feet and Fort Myers averaged 1,032. These are rental figures, not condo figures, but they show how much local building patterns shape unit size.
Legally, a condo is a form of ownership and an apartment is usually a rented unit, as our guide to condominium vs apartment explains, and the words describe the same kind of space. The size gap shows up in the data. Using the same Census method, the 2025 median new unit built for sale was 1,170 square feet, against 1,000 for units built for rent. On averages, the gap was 1,383 against 1,044.
Be careful comparing across datasets. RentCafe's 910-square-foot average and the Census 1,000-square-foot median for rentals are not measuring the same thing: one is an average of apartment floor plans in large buildings, the other a median based on building area per unit. Compare like with like. Words like "flat" do not change the math either, as our guide to the difference between an apartment and a flat shows.
For mortgages sold to Fannie Mae, the method depends on the building's design, not its ownership. Fannie Mae Selling Guide B4-1.3-05 requires appraisers to follow the ANSI Z765-2021 standard for attached and detached single-family dwellings, including townhomes and rowhouses. It also says the ANSI standard "cannot be used to measure apartment/multifamily buildings," and that for an apartment unit in a condo or co-op building, "the appraiser must use interior perimeter measurements."
Fannie Mae's updated measuring FAQs, dated September 4, 2025, add that the ANSI standard applies "irrespective of ownership type" to houses with detached or attached designs. So a townhouse-style condo is measured under ANSI, while a flat in a mid-rise is measured from the inside. Under ANSI, finished areas need a ceiling height of at least 7 feet, sloped ceilings must reach 7 feet over at least half the room and never drop below 5 feet in finished area, and any level partly below grade is reported as below-grade area rather than living area. Our home appraisal checklist covers how that plays out during the visit, and our guide to whether a condo is a single-family home explains how appraisers treat condos generally.
The legal size of your unit comes from the condominium documents. In Florida, Florida Statutes 718.104 requires the declaration to include a survey and a graphic description of the improvements detailed enough to identify each unit and "their relative locations and approximate dimensions." The boundaries in the declaration decide whether you own the drywall, the space inside the walls or only the air between them, which is explained in what a condo is and what you own. Other states set their own rules, so read the declaration for your building.
Fannie Mae's FAQs say square footage in appraisal reports is "already often different from other sources," and note that MLS and assessor figures may not have been derived using the ANSI standard. A developer's brochure might measure to the outside of exterior walls and the middle of shared walls. An assessor might use a different record. An appraiser measuring the interior perimeter will usually report a smaller number. None of them is lying; they are measuring different things.
Price per square foot is only as good as the square footage behind it. An illustrative example: a condo listed at $420,000 with 1,050 square feet works out to $400 per square foot. If the appraiser measures 980 square feet, the same price is about $428.57 per square foot. Compare two units in one building, also illustrative: $399,000 for 900 square feet is $443.33 per foot, while $450,000 for 1,100 square feet is $409.09. In this example the larger unit is cheaper per foot, which is why a single price-per-foot figure cannot value every plan in a building.
Appraisers adjust for size using sales of similar units, as our guide to what comps mean explains. Size can also affect what you pay each month, since the declaration sets each unit's share of common expenses; our guide to homeowners association dues shows how that share is calculated. For the resale and rental angle, see whether buying a condo is a good investment, and when the time comes, our guide to how to sell a condo.
If a condo feels too tight for your household, a two-unit property is one alternative some buyers weigh, explained in what a 2 family home is. If the measured size will decide your offer, ask your agent or an appraiser before you sign, and compare units on Leevli's listings.
Square footage on paper and space in daily life are different things, and owners who have lived with a floor plan know the difference.
Listings show the property, but they rarely explain the lived reality around it. On Leevli, a mover can explore the city, review neighborhood and building information, and ask a verified resident the specific questions that remain unanswered. That human layer helps readers know what to investigate before signing a lease, making an offer, or choosing between two addresses.
There is no single national average for all existing condos. For new construction, the Census Bureau put the median multifamily unit built for sale, which includes condos and co-ops, at 1,170 square feet in 2025, with an average of 1,383. Those figures include a share of hallways and lobbies, so the interior of a typical new unit is somewhat smaller.
The closest dated figures come from apartments. RentCafe's August 2026 report, based on Yardi Matrix data for large buildings, lists averages of 460 square feet for studios, 735 for one-bedrooms, 1,095 for two-bedrooms and 1,355 for three-bedrooms. Condo plans in a particular building can run larger or smaller, so check the floor plans for the units you are considering.
New ones tend to be. Under the same Census method, the 2025 median new unit built for sale was 1,170 square feet, compared with 1,000 for units built for rent. The averages were 1,383 and 1,044. An older condo converted from a rental building, though, usually keeps the floor plans of the apartments it used to be.
For loans sold to Fannie Mae, apartment-style condo units are measured using interior perimeter measurements, while townhouse-style and detached condos follow the ANSI Z765-2021 standard used for houses. Developers, listing agents and assessors may use other methods, which is why the same unit can show different square footage on the listing, the tax record and the appraisal.
Usually because the methods differ. An appraiser measuring an apartment-style condo uses the interior perimeter, while a listing figure may come from a developer's plan measured to exterior or center lines, or may include a balcony or storage. Fannie Mae's FAQs note that MLS and assessor figures may not follow the ANSI standard. Ask the appraiser how the unit was measured.
Studios are the smallest common plan, averaging 460 square feet in RentCafe's apartment data. At the other end, 27 percent of the multifamily units built for sale in 2025 were in buildings averaging 1,800 square feet or more per unit, according to the Census. Penthouses and combined units can be far larger; the national figures do not break them out.
It can. Each unit's share of the common expenses is set in the declaration, and the formula differs from one building to the next. Read the declaration's allocation section before you buy, ask whether special assessments are split the same way, and compare the dues on different floor plans in the same building before choosing a larger unit.
Yes. The Census put the 2025 median new unit built for sale at 932 square feet in the Northeast and 1,538 in the South, though both estimates carry wide error margins. RentCafe found apartments built from 2016 to 2025 averaging 645 square feet in Seattle and 1,156 in Tallahassee. Compare listings against local figures rather than a national average.
Only within limits. It works best for units in the same building measured the same way. A larger unit can cost less per foot than a smaller one in the same building, and floor, view, light and condition also move price. Appraisers rely on comparable sales and adjust for those differences rather than applying one rate per foot.
Comparing listing figures across buildings as if they were measured the same way. One building may count balconies or a share of the hallway while another reports interior space only. Ask how each figure was measured, compare price per foot within a single building, and measure the rooms you will actually furnish.
This article is informational and does not constitute legal, financial, tax or insurance advice.
