Comment by jrochkind1 | Hacker News Reader

Comment by jrochkind1 | Hacker News Reader

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There are plenty 50-100 year old examples (the whole range) in, say, Chicago of mid-rise 4-6 story buildings with retail on the first floor and residential or office on the remaining floors. Chicago is a mid-rise city. Examples which are considered attractive and historic and nobody complains about them... but they aren't timber frame over concrete podium, they're brick or stone on all floors. Which is of course often too expensive to do now. (Although Chicago has all-masonry examples from the past couple decades too... as well as timber-over-concrete examples I think).

I guess it's the timber-over-concrete that is new and without historical example? Or regardless, the issue is that the historical examples are too expensive to build now. (Why isn't this an issue with residential too? I think it is actually?)

Here's a very typical generic Chicago example, which possibly has had it's ground floor facade replaced at some point in an uninspired way, but you can see the masonry on the upper floors (only 3-over-1) which would be an absolute premium luxury build today, and the building has plenty of character even though it's not being used for especially high-rent purposes at the moment: https://www.google.com/maps/@41.9654135,-87.6587315,3a,75y,2...

Here's a new construction (past 20 years anyway) 4-over-1 that is all brick... pretty boring and generic. Would people hate it as much as the timber-over-concrete? I have no idea. https://www.google.com/maps/@41.962424,-87.6661565,3a,75y,26...

Here's a pretty delightful and typical older all masonry 5-over-1, nothing special, tons of buildings like this. https://www.google.com/maps/@41.9582377,-87.6528717,3a,75y,8...

There is no lack of great historical examples of mid-rise 5-over-1 residential over retail -- but they probably aren't timber frame over concrete podium.

My knee-jerk reaction is that traditional building styles are probably not cost-competitive, and modern construction mimicking traditional styles would be perceived as fake and inauthentic. But I stand corrected on the history; thank you.

Aren't traditional styles of single family homes also far too expensive to build now for non-luxury-premium prices too though? I don't think it's special to 5-over-1.

(And indeed, most new construction single family homes are pretty disastrous too?)

I especially love the architecture of Chicago though, it is a delightful city to be in. Many parts of the city managed to have historical building booms at just the right times to leave us with some amazing infrastructure.

But yeah, the OP is talking a lot about how mid-rise density residential-over-retail is great for livable cities -- and I agree! Chicago demonstrates it. 2-5 stories of residential over a retail ground floor is great for neighborhood "main roads". That isn't the issue, the issue is that we just don't like cost-competitive new construction much, whatever the layout.

> Aren't traditional styles of single family homes also far too expensive to build now for non-luxury-premium prices too though?

That's a good question. I'm not an expert, but I think what was cheap in the 20th century is still generally pretty cheap now. A stick-built bungalow or ranch house with siding was cheap then and is cheap now.

I also think there's more room in the market for not-quite-the-cheapest-thing when it comes to single family homes. Like private automobiles, single family homes can be more expensive than they need to be, if the extra cost allows the buyer express their individual taste or their social status. If someone prefers a brick facade, they might pay extra for it, just like they might pay extra to drive a $60k car that has roughly the same practical utility as a $30k car that is also available in the market.

> the issue is that we just don't like cost-competitive new construction much, whatever the layout

Agree 100%.

masonry has some disadvantages. notably you won't really find masonry in earthquake prone areas because unreinforced masonry will kill people and reinforcement is expensive.

I don't think Chicago's extra strict fire code allows for timber 5-over-1 buildings. I don't recall ever seeing any under construction.

That could very well be how they manage to still hae new construction that's all masonry... although as I think my second (all balcony) example above shows, you can certainly do a generic obviously-optimized unpleasant brick 3-to-5-over-1 too! Not sure if people would prefer them to timber-over-concrete ones still.

It also helps that there is a lack of seismic activity to push codes away from masonry buildings and towards materials that will survive an earthquake. Much of the west can’t build masonry because those buildings fail when the ground moves.

In Germany all new construction is reinforced concrete, I always assumed that’s because it’s cheaper than masonry, but might as well be due to the notoriously strict building codes.

Timber is seen as the innovative, climate friendly alternative, but it’s still more expensive than concrete.

All of this is also partly dependent on the region's availability of timber vs. other materials and if they are near fault lines. The eastern half of the USA, including Chicago, is no where near a fault line, so prioritizing less earthquake friendly materials that have other benefits is more practical. The same applies to most of Germany and there isn't any natural forest left to harvest timber from.

West coast USA is an earthquake zone and has a large timber industry in the pacific north west. Not using timber or something else that is flexible is a relative hazard!

Fault line map: https://www.arcgis.com/apps/mapviewer/index.html?layers=37a3...

By reinforced concrete do you mean they build forms and pour the concrete into the forms, or do you mean tilt-up (pour slabs horizontally then lift them to vertical to form wall sections) or do you mean reinforced-CMU (build a CMU wall then put rebar and grout through the cores of the completed wall?

Pouring into forms is by far the most expensive technique because those forms are costly to build and set up. In the US poured concrete is only used in simple or horizontal structures (like foundations) or where the cost of the formwork can be amortized over a lot of repeated structures, like the floors of a highrise.

Chicago doesn't allow 5 over 1s. All those new 3-5 story buildings in Chicago are masonry (CMU) or steel frame curtain wall. I've watched some of them get built. Building out of CMU is cost effective and they can be combined with brick for facades (brick-and-block).

This should put to lie the idea that 5 over 1s are the only way cost-effective way to build. CMU construction is cheap it's just not quite as cheap as timber frame, and developers will always choose the cheapest technique they're allowed to use.

Landowners know how much construction costs, so land prices are probably lower in Chicago as opposed to elsewhere.

If you have multiple developers bidding for the same (in demand) land, then the one willing to pay the most will obviously have to choose to reduce construction costs wherever possible to afford.

Land prices in Chicago are definitely cheaper than other large cities.

But at the same time, the fire code and zoning make it pretty rare that a 6-floor building is the right economic choice. You might as well build it to be 10-15 floors. The approval process isn’t going to be more difficult or time consuming, your per-unit costs will be lower, and there’s no shortage of banks willing to finance it. This is also quite different than most other large cities.

Interesting. Really, the more I think about it, the more I'm dissapointed in the OP. Yes, I totally agree with OP that mid-rise 2-4 stories of residential over ground level of retail is a great livable urban design, and it would be a huge mistake to do anything to discourage or prevent this.

The question is -- what are the constraints on what that looks like, what is it exactly that people are saying they don't like about "5 over 1", let's compare to various historical ways of building several stories of residentail over a ground floor of retail, let's look at what the cost factors and constraints are here, let's compare different cities, let's think about what sort of building codes might lead to different designs, etc.

I want that article!

(To be fair, plenty of new construction in Chicago is pretty bad too. I think that second picture I posted above of residential-over-retail is a pretty ugly and street-unfriendly building, although it gives everyone a front-facing balcony that presumably raised the value of those presumably condos. looks like a parking garage. https://www.google.com/maps/@41.962424,-87.6661565,3a,75y,26... )

Chicago building code is wild.

NM cable (Romex) is not permitted anywhere in Chicago, EMT and wire is used for residences. Armored cable is allowed in some circumstances.

Pex pipe was also forbidden. I think it might now be allowed in limited circumstances.

Interesting. I’ve always heard that labor unions were behind some of these regulations, wanting to protect their market from non-union competition.

Requiring EMT and copper water supply lines both fit this scenario, as it’s harder to bend EMT and pull wire than it is to install NM cable; and it’s harder to bend and sweat copper pipe than it is to squeeze together the handles of a PEX fitting crimper.

Anyone have some insight into the reasoning behind these weird Chicago building codes?

Note that the “5” in 5 over 1 refers to what building code is in effect for the floors on top, not the number of stories.

Looks like kind of yes and no, but thanks, I do see that just commercial on bottom with residential on top but all masonry isn't what people are talking about as "5-over-1", but I still think provides some design precedent.

> The name derives from the maximum permissible five floors of combustible construction (Type III or Type V) over a fire-resistive Type I podium of one floor for "5-over-1" or two floors for "5-over-2", as defined in the United States-based International Building Code (IBC) Section 510.2.[1][4] Some sources instead attribute the name to the wood framing of the upper construction; the International Building Code uses "Type V" to refer to non-fireproof structures, including those framed with dimensional lumber

https://en.wikipedia.org/wiki/5-over-1

Wikipedia is just flat wrong on the history here. Structural engineers created the phrase, and they meant type V, not five stories.

It’s true since the term became popular people have misunderstood, and it happens to match the number of permissible stories in current code, but that’s not what structural engineers meant when they started using the phrase.

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