In the book, Walkable City: How Downtown Can Save America, One Step at a Time, Jeff Speck describes the built environment as falling into two categories: “walkable urbanism” which is walkable, bikeable, and driveable; and “drivable sub-urbanism” which may be bikeable, and definitely is driveable, but is not walkable — at least, not in terms of being able to get anywhere meaningful. Speck also asserts that, “ten to twenty [living] units per acre is the density at which drivable sub-urbanism transitions into walkable urbanism.” Which got me to wondering where our residential neighborhoods fell in terms of that transition zone.

I decided to start by looking specifically at single family, residential neighborhoods, none of which fall into Speck’s walkable urbanism category, despite at least one of the neighborhoods shown below having the sixth highest Walk Score in the city of Fort Collins. That’s because the only way to reach the density that Speck speaks of is to have multiple unit residential properties. Some of the neighborhoods shown below do have multiple family units either interspersed here and there within the neighborhood, or along the edges. This can pop the overall level of density up far higher than it would be otherwise.

But I’m not going to look at those multi-unit properties today — just the single family residential neighborhoods. And I’m only looking at lot size, not the square footage of the buildings on the lot. With U+2 occupancy rules, at the most any of these houses are holding (no matter how large they are) is a family plus one additional person. So when talking about land use, it’s the amount of land holding that living unit that makes the most difference.

Each square shows an acre of land (approximately). I used Google Maps to create the aerial views and I used the Larimer County Assessor website to label each property with the amount of an acre that it covers. (I put the numbers on the roofs of the houses just to make the amounts easier to read. But remember, we’re looking at the size of the lot, not the size of the house.) I’ve also included some rectangular aerial views shown after each square shot so that you can see the acre within a bit more context.

Note: the square aerial shots are all to scale with each other. The rectangular context shots are not.

Old Town West: Walk Score 64, Rank #6

Old Town West

Old Town West

Originally platted in 1887 to only have four lots, this acre of housing in Old Town West was replatted in the 1920s to contain seven living units (including one very small house off of the alley).

But looking at just lots and houses doesn’t take into account the amount of land consumed by streets. And Old Town has some pretty darn wide streets. So even though there are 7 houses on this acre, if you include the street, then you’re looking at 7 houses on 1.6 acres total.

Unfortunately, because many of the other neighborhoods in town have curvy streets, it’s a lot harder to compare living units to total developed acres (including streets). So it’s worth noting street configurations and street widths. But for the sake of this comparison, I’m really only going to be looking at non-street covered land usage. So for our above example, there are 7 houses on one acre of land. That’s less than Speck’s recommended minimum of 10 to have a walkable neighborhood.

Old Town IS a walkable neighborhood, though, according to its Walk Score. That’s because of the proximity of commercial development as well as many duplexes, four-plexes, and apartment buildings scattered throughout the area that increase the overall density of the neighborhood.

The Old Town West acre in context. The image is from the County Assessor website so that lot lines are included.

The Old Town West acre in context. The image is from the County Assessor website so that lot lines are included. Look how wide the streets are! They look to be about two lot widths wide.

University Acres: Walk Score 61, Rank #9

University Acres

University Acres

University Acres was built in the 1960s with the houses shown above all being built in 1965. Although the first suburban-style neighborhood was built in the 1940s in Fort Collins, the population boom of the 1960s and 70s led to huge swaths of farmland being bought up and developed — all with the winding streets and cul-de-sacs that are familiar in suburban growth. These curving streets led to some strange lot shapes that tended to create pockets of expansive, privately owned yards.

This University Acres acre holds approximately 4 houses (when you take into account the fact that most of these lots include space not shown in the above image).

University Acres was one of the first suburban style neighborhoods with curving streets and oddly shaped lots. Circle Drive, just west of this neighborhood was THE first suburban style neighborhood in the city, built in the mid-1940s.

University Acres was one of the first suburban style neighborhoods with curving streets and oddly shaped lots. Circle Drive, just west of this neighborhood was THE first suburban style neighborhood in the city, built in the mid-1940s.

Village West: Walk Score 40, Rank #33

Village West - near Constitution south of W. Stuart

Village West – near Constitution south of W. Stuart

The two houses at the bottom of the above photo are located on a cul-de-sac. They have very large, triangular shaped lots. These two buildings were built in the early 1970s. The smaller lots across the top of the above image are more densely packed, are on a long horizontal street, and were built in the late 1970s. There was definitely still a sense of expansiveness among developments from the early 1970s. Was the more compactness in the late 70s due to dawning realizations that oil was not unlimited and density might be helpful? Hmmmm.

This Village West acre has approximately 3 houses (when you take into account the amount of property not included within the image).

This shot helps to make sense of the large lots in this neighborhood. Cul-de-sacs make it harder to use space efficiently.

This shot helps to make sense of the large lots in this neighborhood. Cul-de-sacs make it harder to use space efficiently. The house on half an acre is shown to the top left of the above cul-de-sac.

Brittany Knolls: Walk Score 9, Rank # about 77 (Not on Walk Scores rank list.)

Brittany Knolls

Brittany Knolls

The first thing I notice about these Brittany Knolls lots is that they’re more uniform in terms of size than the neighborhoods shown earlier. But the overall density is still pretty light. And whereas there might have been possibilities for infill in the Old Town neighborhood (by building off the alley) or in the University Acres or Village West neighborhoods (by creating “flag” style lots), there’s really no way to infill in Brittany Knolls because of those even lot sizes and houses that are built almost lots line to lot line across the property but directly in the middle from front to back, leaving little space for infill development. (That’s a plus for people who don’t want their neighborhood to change. But it puts additional pressure on other neighborhoods to densify as our population continues to rise.)

This neighborhood was built in the early 1990s with the houses shown above having been built in 1993 and 1994.

I’d put the density level here at about 4.5/acre.

Brittany Knolls

Brittany Knolls

Rigden Farm: Walk Score 28, Rank #54

Rigden Farm

Rigden Farm

Density started to increase at the turn of the century (meaning the 2000s). The houses shown here are comparable in size to many seen above, but the lots sizes are smaller than most of what we’ve seen so far (with a few exceptions).

This Rigden Farm acre has approximately 7 houses, putting it on par with Old Town… although in Old Town there is still the opportunity to infill off the alleys (though not currently allowed under City Code), which Rigden Farm, like Brittany Knolls, does not have. Barring off-the-alley infill development in Old Town, Rigden Farm can probably claim to be even denser than Old Town (at least in the single family residential areas) thanks to the fact that the streets here are much skinnier than what’s found downtown.

Rigden Farm was built in the 2000s with the houses above being built around 2002.

Rigden Farm

Rigden Farm

Conclusion – TL;DR

Although I put this article together more as an exercise than to make a point, there are still some conclusions that can be fairly readily drawn from the above examples.

#1: The city of Fort Collins has mirrored the American pattern of building dense residential neighborhoods before World War II, expanding in a more sprawling fashion during the population boom of the 1950s – 1970s (which coincided with the height of the Car Era), and beginning to build more densely since the late 90s with a return to pre-WWII density levels.

#2: Density and Walk Score do not necessarily correlate. The proximity of commercial centers is key. So even though Rigden Farm and Old Town West have similar levels of housing density, they do not come close to having the same amount of commercial development within walking distance, which is why Rigden Farm has a Walk Score of 28 compared to Old Town West’s score of 64.

It’s interesting to note that the proposed 3 Seeds project on the site of Happy Heart farm is currently aiming for a density of about 4.5 units per acre in an LMN zone (Low Density Mixed-Use). The required minimum in the LMN is 4 units per net acre. The maximum required by the City Code is 9 units per gross acre. This is more dense than the next door residential neighborhood to the east but less dense than the apartments just to the west side of the project area. Zoning, preservation of natural or historic resources, and neighborhood expectations all play a role in how our infill projects are realized.

The image at the very top of the article shows a section of the Bucking Horse neighborhood and includes a variety of housing types.

Walk Score is a company with a mission to promote walkable neighborhoods.