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Comment by zackangelo | Hacker News Reader

Every time stories like this get posted, the first question is typically "when will they convert these buildings to residential?". And, like clockwork, there's always someone there to point out that residential conversion is prohibitively expensive and it would be cheaper to just tear the building down and start over.

My question is: is it possible to design high rise buildings in the future that can flex between residential and commercial? What's the extra upfront cost in plumbing, etc to build in this optionality from the start?

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There is a good NYT article on it - old buildings are easier to convert but modern office buildings are huge and you have to literally punch a hole in it.

But it could certainly be designed to be easier to convert, as the older one was easier. The problem you may run into is that the people who want office buildings won't want the easily convertible building; so you might have to legislate that it be convertible.

https://www.nytimes.com/interactive/2023/03/11/upshot/office...

https://archive.ph/gQiQW

Floorplate size. Floorplate size. Floorplate size.

If you required all new office buildings to have the same small floorplate size of a residential building, then they would be convertible, but thay would significantly change the economics of commercial real estate.

Maybe build a new kind of housing that is INSIDE the large open place office, and doesn't need to have the same structural integrity, but focus on noise reduction and being secure from external entry?

Like a bunch of tiny homes inside an open plan office.

People want windows and natural light. That's the fundamental problem here that this doesn't solve.

Tall steel-and-concrete buildings are still structurally sound with all the facade torn off. (After all, they were structurally sound before the facade went on.) There'd be plenty of light and fresh air for these "indoor houses" — at least the ones around the outside — if this was done.

If you want even more light and air, design office towers to have some extra "wasted" central space, beyond just that needed for an elevator shaft and plumbing — i.e. make them into squared-off toruses. Then, post-facade-stripping, it won't be dark in the middle, either.

Or just build office towers that are long and narrow, rather than square, such that if you convert them into residential, you get functional "commie block" architecture where every unit gets not only a window, but a balcony.

Counterexample, WTC 1&2, whose concrete columns around the outside supported it.

A Counterexample: WTC 1&2, whose concrete columns around the outside supported it.

I wish courtyard-like shapes were more common in western architecture.

That's actually true for offices as well. That's also why highly paied people are running away from offices.

I think the problem with residential is more that people might block each others air supply ... and what to do when that happens.

I think to live for a reasonable price in SF, a lot of people would give up the natural light. I likely would. I'd just use it as a place to sleep and spend my time somewhere else.

IANAL but there are city housing code minimums around natural light in residential units. If the goal then is to change the housing code to let people live in SF for a more reasonable price then might as well skip to removing overly restrictive zoning and height restrictions instead.

So my office is a sunless dungeon that I don't get to see outside? Sounds awful.

So, in other words, the requirement that offices are unwieldy uncomfortable spaces conflicts with the requirements that people feel well inside their homes.

I keep wondering where do the office requirements come from, but I know I won't like the answer.

The residential units go round the outside* and the inner core of the building is used for creative space, retail, services and so on.Just needs a little imagination.

* round the outside, round the outside

You only have to start over if you're not going to have communal bathrooms and kitchens.

For the latter, many of these buildings do punch holes for restaurants closer to the ground floor.

The part we don't talk about in zoning and missing middle conversations is that the US eliminated the lowest income housing, which was temporary, single occupancy, with shared resources ie the Saloon, brothel, short term rent, and multi-tenant housing in the 70s.

Buildings don't have holes punched in them on the ground floor for restaurants! Buildings are almost always the widest at the base (for obvious reasons).

"Punch holes" means actually removing building mass, not just adding windows. The floor plans on office buildings are so massive that you literally need to punch holes into every floor to bring windows inwards for apartments. This is a good example: https://twitter.com/SustainableTall/status/16572851981518315...

Funny, I would much rather work in a building with inward windows, parent comments about regulating this into existence are starting to sound pretty reasonable.

Do we really need windows? Yes, I'm channeling my inner Munger. We could have simulated windows, and as long as the HVAC is good I think a lot of people would live in a place like that, especially if those apartments sold at a discount relative to windowed apartments. It seems crazy to not even give the people a choice of whether they want to have a window or not. You could trial it on luxury apartments so no one can say "Well they don't have a choice they have to live in an apartment with no windows".

Well, and tenement housing was eliminated before that. There are presumably some proper minimum standards though people will reasonably on what those standards should be.

Nobody...well, very few people want communal bathrooms and kitchens. If my time in offices taught me anything, it's that everyone else is a damn slob.

With SF rents I’m sure many people wouldn’t mind a cheaper option even if it’s communal

residential conversion is prohibitively expensive

You're quite right about how the discourse goes, but let me suggest that just as the office space targets and economics are now badly out of date, so are the default assumptions about how space can and should be used. Bureaucrats by nature are incapable of creativity, and their inability to solve the problem means their opinions should be heavily discounted. This isn't to say they have no role to play; after some new solutions emerge, they can look at the ups and downs and codify some new standards. But in a problem situation, they are just in the way.

The problem is, it is difficult to convert modern commercial building to have tiny 500sqft apartments. But it is not a problem to convert to 2000sqft apartments.

I did some fun math yesterday, the Empire State is 102 stories and valued at 1 billion and 2.73 million square feet. Each floor therefore is ~26,000 square feet and ~$9.8M.

If you divided each floor into 10 2,600 square foot ultra high end condos, the pre-improvement base cost would be $980,000 per unit. You could then turn around and sell them for probably at least $3-4M. Assuming buildout/sales costs of $1M per unit, you could conceivably clear $1M-2M in profit.

What's the point? Buildings don't cost anything. 90% of the value of these buildings is the land they're on.

What? In SF? Where construction costs alone are easily several hundred million dollars for a modern office skyscraper?

Permits cost more than construction.

> Every time stories like this get posted, the first question is typically "when will they convert these buildings to residential?"

HN needs some AI to just autofill "asked and answered N times already - see here:..."

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