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Comment by rr888 | Hacker News Reader

I live in one, it isn't that awesome. Lots of noise from neighbours, but the worst thing is the big fire hazard. The risk of fire means there is a lot of sprinklers everywhere which regularly get damaged and leak everywhere. Usually every 2-3 years in our building a sprinkler pipe will get broken or leak will appear and destroy a few units.

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There’s some massive variance in 4-over-1 and 5-over-1, with newer units very much built to a price.

I lived in one in Boston that was 4 total floors, actually all steel framed (so not really a 3-over-1), polished concrete floors in every unit, and built to the tune of $55M for ~150 units. Was intended to be condos, bottom fell out in 2007/2008, so it was rezoned to apartments. Dead silent in the over 8 years I was there. I must’nt of been the only one that thought it was good — there was a notable rapper as my next door neighbor, and a Stanley Cup winner in another hallway on my floor. I moved in when the market bottomed out, and paid like $1700/mo for years (moved out when it went up to $2450). I think it’d be ~$4000/mo now.

The newer ones though? I’ve heard of sub-$20M costs for similar number of units. They leak not because of the sprinklers, but because the general waterproofing and roofing is beyond awful, and just cost-cutting everywhere. I talked to some maintenance folks that had been to several new ones owned by the same company as the $55M one: “They don’t build them like that anymore. If they did, we wouldn’t be dealing with constant problems.”. Talk up your maintenance folk — they’ll be more than happy to vent about your building’s issues.

So the issue is building things to a price, knowing some people will pay because the vacancy rate is one of the tightest in the country.

It's also a matter of information asymmetry. Most potential renters or buyers don't have a good way to check for construction quality and interior noise levels. Even an independent pre-purchase inspection doesn't tell you much beyond really obvious problems. Customers aren't willing to pay more for higher quality because they can't easily determine quality, so most developers will go with the cheapest possible option and then slap on some granite countertops to make it look nice.

This could be addressed through stricter building codes. But that would drive up construction costs at a time when we already have a housing shortage in many areas.

Another fix would be to independently measure noise isolation and report that, so renters can actually make decisions based on it, and builders would have an incentive to include it, since they could more reliably charge more for it.

Someone should do that with good branding. Sorta like carfax. Call the Zillow Report or find a similar firm. License the standards and a saas interface to Inspectors to have another revenue stream (or maybe more broadly to contractors). Then it could become a defacto standard, especially if you get in with real estate agents.

I've lived in multiple of them, and they were often about the same or better than more "traditional" apartments in the area. Usually way lower energy costs than the traditional units. About the same amount of noise for a given build quality, it mostly depended on who lived in the neighboring units.

There were sprinklers in every apartment I've lived in. Building codes in my area require them in any structure with multiple households sharing the structure. Townhouses, apartments, commercial buildings, etc. all have sprinklers everywhere. It doesn't matter if its a high rise or a duplex, if it was built since like the early 90s its got sprinklers.

The issue with the modern apartment building noise, in my estimation, isn't wood construction (which is commonly blamed), but ducts. The double-loaded corridor requires extra ventilation per fire code. The demand for central air conditioning implies ducts. A properly designed double-stud wooden wall can have a Sound Transmission Class higher than 60, but a small hole in a wall can cut the STC by as much as 30. The presence of a large void in the wall (duct) could severely reduce the efficacy of the sound insulation.

http://en.wikipedia.org/wiki/Sound_Transmission_Class#Sound_...

The apartment buildings I've lived in without central A/C (in Atlanta and San Francisco) were consistently quieter than the ones with central A/C. Underfloor radiant heating and wall A/C units might be a better way to design apartment buildings. Removing climate control from the access corridor and letting it vent to the outside would reduce the need for sprinklers and complex ventilation. This is slightly less energy efficient, but apartment buildings are already way more energy efficient than houses, and anything that makes apartments more livable can increase the efficiency of the whole society by increasing people's willingness to live in apartments.

You shouldn't be sharing any air with you neighbors, so I doubt ducts are to blame. You can build highly sound-proof timber-framed walls, but most people don't because it's more expensive. Like everything in modern construction, the cheapest permissible option usually wins.

> The apartment buildings I've lived in without central A/C (in Atlanta and San Francisco) were consistently quieter than the ones with central A/C.

When were the units built?

> You can build highly sound-proof timber-framed walls, but most people don't because it's more expensive. Like everything in modern construction, the cheapest permissible option usually wins.

Especially when reduced cost is the reason mid-rise wood construction became popular in the first place.

I don't think it's about sharing air. It's about the duct being in the wall at all.

You can puts ducts in a soffit so they don't necessarily need to be inside the walls. I've lived in two apartments with ducts inside soffits. Both were still very loud.

A soffit must necessarily pass through the wall. Unless it is well-designed, it could cause the same problem.

It passes though a wall, but not necessarily a wall you'd share with a neighbor typically. For instance, in my apartment we had an in-unit air handler with soffits running long the ceiling. We could hear every step on neighbors made. Most building codes require fire separation between units, so you generally wouldn't have duct work running through walls like that as it'd be a path for fire to spread.

How old was the building? Currently I'm in a noisy building — it was built in 1890, before rock wool was invented, to say nothing of fiberglass. It definitely tracks that floors tend to be worse than walls (especially bad with Euclidean zoning that encourages low ceilings and thin platforms).

The building was built in the 90s. Ultimately, the construction was very cheap.

>When were the units built?

1962 (Atlanta) and 1978 (San Francisco).

I think the issue is that the people building wood apartments aren’t the same people who care enough to ensure there are no small holes in the wall.

Actually its a good thing about our condo is independent heat pumps per unit so everyone gets their own air handler and ducts. Its expensive to replace each one individuall though.

Likewise - I've lived in these 5 story things and in proper high rises, and there is no comparison. It's likely that the 5 story buildings could be built to the same standard as a high rise, but there is little incentive for the builders to do so, and instead they're absolute lowest bar of quality.

Just the elevator speed makes a huge difference: I could get to floor 18 of the most recent high rise I lived in quicker than floor 3 of the mid rise.

IIRC sprinkler systems are just code now for all residential construction. Even new build single family homes must have them.

How new? I've never seen a sprinkler in a SFH, including one I was in built ~2018-2019.

https://www.dalkita.com/sprinklers-in-single-family-resident...

> Surprisingly enough, sprinklers have actually technically been a requirement in all single family homes per the International Residential Code, since 2006. Regardless of home size, location, or construction type. IRC 313.2 states:

    R313.2 One- and two-family dwellings automatic fire systems.
     An automatic residential fire sprinkler system shall be
     installed in one- and two-family dwellings.

> Period. It's just simply required. Only exception is for alterations or additions to existing building without sprinklers.

Your link seems to suggest the opposite above that quote.

> They base the need on distance to nearest fire house and nearest credible fire hydrant.

So there are obviously situations where SFHs do not need automatic sprinkler systems.

Most of my subdivision was built after 2006; none of the homes have sprinkler systems but there are also fire hydrants every 5 or 6 homes so I imagine that has something to do with it. The fire house is also a ~90 second drive down one street (at the speed they'd be going).

Possibly... and also the next bit:

> So, why don’t we see every newer house since 2006 with sprinklers? Because most jurisdictions amend their local codes to delete this requirement. Only CA, MD, & Washington DC now keep this requirement.

> Most jurisdictions delete this requirement for various reasons, but the obvious one is the uproar it causes from citizens, builders, etc , because with this new requirement, comes increased cost.

So while its in the building code, local codes may relax that.

California code requires this when the SFH is 3,600 sqft or larger.

https://library.qcode.us/lib/temecula_ca/pub/municipal_code/...

yeah—I feel like this is something that can be solved by code modification to expect better. 5-over-1's are already min/max'ing code, so if they're fire hazards, then we should expect cities to rein it in. Safety shouldn't be what makes 5-over-1s fail.

I would like to live in one instead of my current situation but the noise is what is concerning. Newer units should be more quiet than past buildings. I don't know what modern building techniques they use, if any, for sound isolation. Are there airgaps? I'm guessing no concrete slabs between floors? To me it seems like it's the difference between a high rise hotel/apt where it's like a tomb in the room and a smaller building that uses less expensive/more robust material and you can hear much more from the outside and your neighbors.

I'm sure it varies a bit, but generally not good in my experience. Except between the ground floor (usually retail, lobby, parking, etc...) and above everything is wood, no concrete slabs. They typically use the cheapest, least sound isolating materials so neighbor noise, both through walls and floors, is very noticeable. It's a bit jarring because they are modern and not usually low cost, but isolation is much more like the smaller building since they share more construction techniques with a cheap two-story row apartment.

> and not usually low cost

> they share more construction techniques with a cheap two-story row apartment.

Low in cost, high in price, builders love it.

I discussed this issue a bit with someone who worked for a company that focused on affordable housing, and he told me a "joke": what's the difference between a regular condo and a luxury condo? The price.

Yeah I lived in one (in the Domain in Austin) and one thing that bothered me about the noise, was that I would hear it from the unit above me through my side wall. That is, if they played loud music or talked loudly, it sounded like it was coming from the side, not from above. (Specifically, the side that was the end of the building and didn’t adjoin another unit. I was on the first floor.)

I've seen multiple condos in San Francisco in 5 over 1 that have perfect sound insulation, generally they're on busy streets though (and thus you don't really want to live there).

In most buildings there is no concrete between walls but floors have a ~1 inch layer of lightweight-concrete, I think for fire resistance, its not solid so you hear every footprint.

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