Conventional planning wisdom tells us that smaller city blocks are generally preferable to larger city blocks. They make for more interesting walks (which can change our perception of distance) and they improve overall connectivity. This is why you'll often hear planners advocate for things like "mid-block connections." It is a way of creating the feeling of smaller blocks.
Salt Lake City, as we have talked about, is the opposite of this. Its blocks measure 660 feet x 660 feet (call it 200m x 200m for those of us more accustomed to using the international standard for measuring things). This means that if you were to walk only 2 blocks (inclusive of 2 streets), your walk would be close to 500m, which is a commonly used walking/transit radius.
Things get a bit tricker when you're not walking in a straight line. For example, if you found yourself wanting to cross a street somewhere in the middle of a block -- and you wanted to obey all traffic safety rules and not jaywalk -- you would need to walk over 200m just to get to the opposite side. So basically a whole other block.
There are also instances where even this street grid gets interrupted. This past weekend, I spent an evening walking to and from dinner on Main Street. And at one point, I got caught trying to cross the convention center (which occupies 3 blocks). I guess I could have tried to cut through, but I walked around, which added 2 additional blocks (~600m in total).
Thankfully, SLC also has many instances of new mid-block streets/connections, road diets, internal laneways, and enhanced center medians, among many other things. I mean, here are some plans to turn Main Street into a pedestrian promenade. All of these interventions are an effort to soften the city's underlying block structure, which we know tends to be indelible in cities.
In 1620, an Englishman by the name of Edmund Gunter invented a land surveying device known as Gunter's chain. As the name suggests, it was an actual chain (see above). Each chain contained 100 links and, when fully extended, it measured 66 feet.
We are into the final push at Parkview Mountain House. The radiant tubes are in for the heated driveway and walkway (essential), and the concrete is scheduled to be poured later this week. The kitchen countertops were installed this morning, and the backsplash was templated, with install scheduled for this Wednesday. The finish carpenter is back this week, and then the painters will be coming next week. The appliances and hot tub are also on standby in their respective warehouses and will be delivered to site as soon as the team is ready. As always, things are frenetic. But we're pushing to get occupancy this month. I'm also excited to announce that we just hired an excellent management company. We're in the midst of that onboarding process, and we're looking forward to starting bookings sometime this fall. If you haven't yet added yourself to our list, drop your email over here. We'll be offering a bunch of discounted bookings on a first-come, first-served basis to the people on this list.
This was a monumental innovation as it greatly simplified land surveying and made it a lot easier to measure out acres -- especially if you maybe weren't great with math. So it is perhaps no surprise that this simple device forever changed our cities.
But first, here's the only math you need to know:
Number of chains x number of chains / 10 = number of acres
For example:
A lot measuring 66 feet by 66 feet would mean it has an area of 4,356 square feet, or 0.1 acres (1 acre = 43,560 square feet). It would also mean that this lot measures 1 chain by 1 chain, or 1 square chain. Take 1 square chain and divide it by 10, and you arrive at the same 0.1 acres.
Similarly, a lot measuring 660 feet by 660 feet would mean it has an area of 435,600 square feet, or 10 acres. Using Gunter's chain, this lot is 10 chains by 10 chains, which equals 100 square chains. Divide 100 square chains by 10 and you arrive at the same 10 acres.
Put differently, 1 acre equals 10 square chains in Gunter's system.
Because of its simplicity and utility, the chain became a statutory unit of measurement in England by the 1670s. And as a result, it spread throughout the British Empire, meaning it started to influence how new cities were being planned and laid out.
Let's look at the example of Salt Lake City.
We have spoken before about the city's famously large blocks. They have the dubious distinction of being the largest in the US. But what you may not have noticed is that the typical SLC block measures exactly 660 feet x 660 feet. Its typical streets are also 132 feet wide.
This is because of Gunter's chain. These are 10-chain x 10-chain blocks and 2-chain streets.
The same is true of other cities. Looking on the other end of the spectrum, Portland's compact street grid is comprised of blocks that measure 198 feet x 198 feet. These are, in other words, 3-chain blocks. Its typical streets are also 33 feet wide. So half-chain streets.
Units of measurement have a lasting way of influencing how we plan and design things. This is true at small scales and it's also true of our cities. In tomorrow's post, we'll look more closely at Salt Lake City's street grid and what it does to walkability.