Renton Homes With Basements: Where the County Records Them

Renton homes with basements are common on the hills and rare on the plateau. Four in five Renton Hill homes have one, and fewer than one in five in the Highlands. Listings mention a basement one home at a time, and the word can mean a finished family room, a crawlspace-height cellar or a garage tucked under the house. The King County Assessor records the basement area, the finished area, any basement garage and whether the basement is a daylight basement for every home it values, so we read the whole record.

At The Rache Team we have guided Renton buyers and sellers for more than 26 years. For this guide we pulled the Assessor’s residential building file in October 2026 and measured the same 12,266 single-family homes in our six neighborhoods that we used for our guide to Renton home sizes by neighborhood. This is housing stock, not inspection advice: the record says where basements are, not what condition they are in.

How We Counted Renton Homes With Basements

The Assessor’s residential building file lists the main house on each parcel with four basement fields: total basement area, finished basement area, basement garage area and a yes or no daylight basement flag. We counted a home as having a basement when its total basement area is above zero, and as having a finished basement when any of that area is finished. Neighborhoods are sorted with the Assessor’s own area codes, loaded by parcel so newer plats with a blank zip code are included. Condos and apartments are not in these figures.

Four things to keep in mind as you read:

• Finished basement is part of the recorded living area. As our home sizes guide showed, the county’s total living area is the above-ground floors plus finished basement on almost every record. Unfinished basement is not counted.
• A basement garage sits inside the basement figure. In all 2,151 homes with a basement garage, the garage area is part of the total basement area. A recorded basement can be mostly or entirely a garage, and 86 Highlands homes have a basement that is nothing but garage.
• The daylight flag has gaps. A daylight basement, in the usual sense, has at least one wall open to the yard at ground level. Of the 5,199 homes with a basement, the daylight field is blank on 970. The gaps are worst in Skyway (27% blank) and on Talbot Hill (23%). Where we give a daylight share, it is the share of homes where the county filled in the field.
• The record shows area, not condition. Ceiling height, moisture and permits for a finished lower level are not in the file.

Renton Homes With Basements by Neighborhood

Here are Renton homes with basements by neighborhood, from the highest share down.

Renton Hill: 81% Have a Basement

Renton Hill has the highest share of Renton homes with basements. Of its 235 single-family homes, 190 have a basement, the highest share of the six. But the hill’s basements are often unfinished: 29% of all homes have a basement with no finished space, against 4% in the Highlands. Only 52% of Renton Hill homes have a finished basement. The daylight split is close to even, 96 yes and 90 no.

Age is the pattern. Of the 98 homes built before 1940, 91% have a basement, but only 39% have a finished one. The Renton Co-op Coal Cos Acre Tracts No. 1 plat, with a median year built of 1938, has a basement on 88% of homes and finished space on 58%. Homes built from 1950 through 2009 are far more likely to have finished the lower level. Many Renton Hill lots slope, which our guide to Renton steep slope homes maps lot by lot. Our Renton Hill neighborhood guide covers daily life up the hill.

Earlington and the West Hill: 69%

The city’s West Hill streets have 725 single-family homes, and 501 have a basement. Finished space is common, at 57% of all homes, and the median finished basement here is 870 square feet, the largest of the six. In the county sub-area on the slope above the lake, 74% of homes have a basement and 65% a finished one.

By plat, Conners Lake View Park, built in the 1960s, has a basement on 92% of its 50 homes. The older Earlington Addition, with a median year of 1948, has one on 71%. Woody Glen Addition, at 43%, is the low point. The Earlington neighborhood guide has more on the streets.

Skyway-West Hill: 62%, With Basement Garages

Skyway-West Hill has the most Renton-area homes with basements by count: 2,653 of 4,307. Of those, 86% have finished space, so 53% of all Skyway homes have a finished lower level. Skyway also leads on basement garages, with 25% of all homes having a garage in the basement, the highest share of the six. Where the county filled in the daylight field, 70% of Skyway basements are daylight basements, but the field is blank on 728 of them.

The split runs by era and by plat. Skyway homes built from 1950 through 1969 have a basement 69% of the time, against 49% for the 1940s. The two Lake Ridge plats, 681 homes from the early 1950s, are at 79%. The wartime plats sit lower: Seelye Addition at 22% and Seattle Heights Addition at 16%. Skyway Village, the newest plat, built in 2023 and 2024, has a finished basement and a basement garage on all 56 homes. All three county sub-areas of Skyway land between 58% and 63%, so the pockets in our guide to Skyway West Hill neighborhoods differ less on basements than on price. Our Skyway-West Hill neighborhood guide covers the area in full.

North Renton: 55%, Mostly Unfinished and Not Daylight

North Renton surprises. Of 360 single-family homes, 197 have a basement, more than half. But only 98 of those have any finished space, and the county marks just 3 of the 192 it recorded as daylight basements. Only four homes have a basement garage. These are the full-depth cellars of the 1920s and 1930s houses on the flat valley floor, where there is no slope for a lower level to open onto.

The Renton Farm Plat, with a median year built of 1924, has a basement on 62% of homes and finished space on 27%. The Car Works Addition is at 51% and 31%. Of the 28 North Renton homes built since 1970, only one has a basement. Our North Renton neighborhood guide covers the grid, and our guide to Renton flood zones covers where the valley floor sits on the federal flood map.

Talbot Hill: 43%, Mostly Daylight

Talbot Hill sits in the middle for Renton homes with basements: 667 of its 1,545 single-family homes have one. Where it holds a basement, it is usually a daylight basement: 425 of the 513 recorded, or 83%, the highest share of the six. The daylight field is blank on 154 more.

The basements are in the 1960s through 1980s plats on the hillside. Victoria Park No. 3 and No. 4, built in the 1970s and early 1980s, have a basement on 76% of homes, nearly all finished. The newer plats mostly do not: Sunnybrook, built from 2004 to 2009, is at 9%, and Winsper Division 1 at zero. Only 18% of Talbot Hill homes built from 1990 through 2009 have a basement. The Talbot Hill guide walks through each section.

Renton Highlands: 19.5%, the Smallest Share

Of 5,094 Highlands homes, 991 have a basement. The two county sub-areas differ again, as they did on size:

• Western and central Highlands: 3,018 homes, 25% with a basement and 18% with a finished one.
• Eastern Highlands: 2,076 homes, 12% with a basement. Where there is one, it is almost always finished, and 64% of the recorded ones are daylight.

Era sets the pattern here more than anywhere. Highlands homes from 1970 through 1989 have a basement 68% of the time; Highbury Park, built around 1984, is at 91%. Homes from 1990 through 2009 have one only 8% of the time, and many large plats from those years have none: La Colina’s 138 homes, the four Liberty Ridge phases and Maureen Highlands all record zero. The postwar President Park plats are mostly slab or crawlspace homes too, at 0% to 19%. One more thing to check: Cobblestone, built around 2005, shows a basement on 70% of homes, but none is finished and the median basement equals the median basement garage, 480 square feet. The basement there is the garage. Since 2010, basements have come back on some Highlands plats, at 22% of new homes, with Claremont at Renton Phase II at 72%. The Renton Highlands guide covers both halves.

What the Record Says About Renton Homes With Basements by Era

Across all six neighborhoods, the year a home was built predicts which are Renton homes with basements better than the neighborhood does:

• Before 1940: 73% have a basement, but only 35% a finished one.
• 1940s: 47%, with 33% finished.
• 1950 to 1969: 49%, with 46% finished.
• 1970 to 1989: 69%, with 65% finished, the highest finished share of any era.
• 1990 to 2009: 16%, with 13% finished, the smallest share of any era.
• 2010 and later: 40%, with 37% finished.

That is why the Highlands, where most homes date from 1990 to 2009, has the fewest Renton homes with basements by share, and why Renton Hill and North Renton, the oldest pockets, have high basement counts but low finished counts. Our guide to Renton home ages by neighborhood has the era mix for each area. Note that its Highlands figures predate the correction in our home sizes guide.

What Renton Homes With Basements Mean for Buyers and Sellers

Renton Homes With Basements Read Larger on Paper

Across the six neighborhoods, homes with a basement have a median recorded living area of 2,060 square feet, against 1,740 for homes without one. In Skyway the gap is 2,120 against 1,320. Much of that difference is the finished lower level, which makes up a median of 36% of the living area in homes that have one. When you compare a Skyway house with a Highlands house at the same square footage, you are often comparing a one-story home with a finished basement against a two-story home with none.

Not Every Basement Is Living Space

Renton homes with basements do not all have the same basement. A recorded basement can be a finished family room, an unfinished cellar or a garage. In North Renton and on Renton Hill, more than a quarter of all homes have a basement with no finished space. In Cobblestone and other tuck-under plats, the basement is the garage. When you shortlist Renton homes with basements, and before you count a basement as a bedroom or a rental space, look at what the record shows and then look at the space.

Daylight Matters, and the Flag Is Incomplete

A daylight basement gets natural light and usually a door to the yard, which changes how the space lives. The county’s flag is a useful first check where it is filled in, but a blank is common in Skyway and on Talbot Hill, so a tour or the listing photos are the real test. For views from the upper floors of the same hillside homes, see our guide to Renton view homes.

How to Check a Home’s Basement Before You Tour

1. Look up the parcel. The King County Assessor’s parcel lookup shows total basement, finished basement, basement garage and the daylight flag.
2. Subtract the garage. Take the basement garage area out of the total basement to see how much of the lower level is not garage.
3. Compare it with the listing. If the listing counts more finished space than the record, ask when it was finished and with what permit.
4. Check the street. On plats where almost every home has a basement, one without is unusual, and the reverse is true too.
5. See the space. The record cannot tell you ceiling height, light or layout. Only a tour can.