Comment by deltarholamda | Hacker News Reader

Comment by deltarholamda | Hacker News Reader

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>If you can buy the building cheap enough, conventional wisdom can be thrown out the window.

Maybe, but you can't throw out the building codes. A warehouse, certainly, can be retrofit. But office towers? Almost certainly not.

Elevators are not sized for residential; electrical service not sized for residential loads (dishwasher/dryer/microwaves/ovens); HVAC not sized for residential heat loads (same as above); metering requirements means the existing electrical rooms are not large enough (they are never large enough); plumbing and sewer are not sized for residential.

It goes on and on. Even if you got the building for free, you'd still want to run the numbers to see if it's still cheaper to demolish and build again. It's not entirely clear whether it is or is not.

It can be done if you make huge, expansive apartments, which has to be read as "really expensive". There aren't that many really rich people who can drop 5 figures per month for an apartment.

I've never seen a high-rise office elevator bank smaller than a residential one.

Dishwashers are negligible; microwaves are a souped-up gaming PC and run a lot less; ovens and dryers are more of a concern, but as with HVAC, I'd like proof that an office's draw (with all its attendant equipment) is more than the what you'd have with a dozen (tops) condos. Plumbing and sewer are the only legitimate concerns I've seen yet. And yet: will, way.

>you'd still want to run the numbers to see if it's still cheaper to demolish and build again

These numbers never include externalities like the carbon and refuse footprint of demolishing and rebuilding. How many million metric tons of steel and concrete do we need to dispose of if this becomes a de-facto national policy?

Most non-mechanical equipment electric loads in standard office buildings are receptacles. This is small. Per NEC, I think it's counted as 180VA/receptacle. So the 208/120V panels are sized for that.

Also, the lighting is probably 277V in an office. This precludes any owner-installed fixtures, the super has to do all of that. Moving it to 120V means more transformers, for which there isn't room without sacrificing rentable space.

HVAC, assuming CW/HW to VAV boxes, has the pumps sized for the number. Which may be less or more in residential, depending. It also precludes (or at least makes very difficult) the ability to meter HVAC usage per apartment.

The point isn't that is is impossible. It's just expensive. That expense has to be borne by somebody.

I vote for the construction companies to be held liable. That way any future office buildings they construct will be more easily converted to housing.

Tearing down good buildings and building new is wasteful and causes more pollution then repurposing. These for profit corporations externalized these costs upon us repressing.

Planning for those who plan to use planned obsolescence to generate a profit.

I don't understand your point:

Construction companies build what they were told to build by developers, and developers decide to build stuff by guessing the balance between financial viability and usefulness to users.

In the past there was a need for office space, and there was specifically a need for buildings which are cost optimized for office work. So the developers designed their plans and investment that way, and the construction companies built them.

What is your idea? That it shouldn't be possible to build something that's expensive to convert to residential housing ? Then that'll just make all other types of buildings more expensive, so you'll hurt manufacturing, businesses, public institutions, etc. If you want the construction companies to pay for it, they'll just not build it.

Interestingly, he's not all that far off in a sense. Many commercial buildings used to be built to be multi-functional. The old school classic 3-story brick, with a shop on the bottom, maybe a workshop above, maybe residential (plus rentable space) on the third.

But once you choose high-density, you don't get much in the way of do-overs. For much the same reason that once you choose thinness as a positive metric for laptops, you lose a lot of flexibility.

Yes it's all about tradeoffs, but I think it's useful to accept (e.g.) in the laptop case that having thin and portable devices isn't necessarily a bad thing and it's likely that a good chunk of consumers will want that even if we create economic incentives and policies to encourage recycling and reuse.

I personally don't think it'd be bad to have a larger chunk of buildings be more versatile but you'd lose some of the economic efficiencies (agglomeration effects and positive spillovers) from the concentration of firms in business districts etc.

In every scenario you win some and lose some, and it's not always clear to me we should go all in on any of the bets.

I understand electrical and plumbing, but why does the HVAC need to be bigger/smaller?

Just conjecturing, but I assume an apartment contains more ovens than an office.

Would probably make it take more cooling?

They also contain lot less people. Average person generates 70-100W at rest. Add that to what ever screens, computers, extra lighting. And it is not that big difference in load.

HVAC has to account for the BTUs produced by all equipment. An office might have one or two refrigerators per floor, maybe a dishwasher. Apartments will have one in every apartment. Ditto for ovens, dryers. Even computers and TVs.

Offices have a lot more people per m² all of them using computer equipment continuously for 7hrs/day so in my experience they tend to have considerably higher cooling loads. I know from experience that a typical high rise office building in London, UK will have no heating requirement for most of the year; it is in cooling mode most of the time.

You have to account for peak usage, not median. At 7AM and 6PM, everybody has their stove or ovens going to make dinner, plus the washing machines and dryers.

Building codes and practices are different for commercial and residential for good reasons.

In any modern building there should be raceways where new electric can be run vertically and then through hallow drywall walls. Very easy. The big problem will be plumbing. While you can get wall mounted toilets, I don’t think you can avoid having to trench each shower drain into the existing, likely concrete, floor.

it's also possible for offices to be doing poorly but also still make more money than as a residential property. while vacancy rates are high, those vacancies are spread around, so some people are still renting in these office buildings. if you want to redevelop them you have to get the existing tenants out.

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