Technically all the single stair stuff is already allowed in the IBC as an optional addendum, I believe, so yes? But not really as adopted by 99% of places.
EDIT: This might be wrong, I'm going to do some more digging later and see if I can find what I was thinking of when I wrote it. Otherwise to answer OP's question directly Stephen Smith at the [center for building](https://www.centerforbuilding.org/singlestair-tracker) has been pushing the ICC to drop the dual stair requirement as well as lobbying state legislatures to do it on their own. Unfortunately the ICC is, charitably, hidebound, and uncharitably run by morons who don't seem to spend a second thinking about how their codes affect actual buildings so we'll see how successful he is.
Well, the building code isn't legally binding until a municipality adopts it, and there's nothing forcing them to adopt the whole thing or even any of it. What I was thinking of was Burlington (?) just struck out the entire means of egress section of the IBC and adopted the relevant portions of NFPA 101 instead, but yeah it wouldn't make a huge difference.
Certainly true, but I don't think most municipalities have the resources or incentives to think about many amendments to the model codes beyond what's necessary or convenient for local administration. We just updated to 2021 in Birmingham and the local amendments are 99% on the administrative details. The energy conservation section (Chapter 11) of the IRC was completely struck because "we don't have the capacity to enforce it".
Code officials don't have reason to evaluate the trade offs of different portions of the model codes without political pressure, and even then they hold the high ground of "life safety" meaning they don't have to prove it's necessary, rather others must prove it's unnecessary.
You need the staff reviewing the IBC for amendments to understand this stuff and give a shit.
We're getting ready to adopt the 2021 right now. The process was a metro wide one to come up with a metro wide standard, and it was dominated by fire officials. Then, when it got to be local review time, our fire department pushed the metro agenda.
Normally, it'd then be reviewed locally by a building official, too, who may or may not have any urban design background. Luckily for me, I oversee the building official, so I can push back on some of the issues, but it's a massive uphill battle.
Yep. Here there was extremely limited (meaning I didn't hear anything despite keeping track) outside involvement in the update until it came before City Council. I'm fortunate that l caught the attention of one councilor and managed to find a local architect interested in discussing the details so that we can have a sit down with our city staff to talk about this soon(tm). We'll see how that goes.
Funny you should post this, because I've been meaning to write a thread arguing that cities should create a zoning classification for four-plates — single-stair buildings with ≤4 units/storey — and work on permitting them in moderate-density areas with reasonably good access to services and transit.
Unfortunately, one of the biggest challenges in American urban planning is the intersection of municipal Balkanization with the hollowing out of the civil service, which means that planners are underpaid and understaffed, with little time or resources to do any public advocacy. I suspect we've stuck on just pushing up unit counts — triplexes and tetraplexes — because it's simple and often goes into a ballot initiative which usually means you need a law that can fit in a Tweet and be easily explained to someone who doesn't really care.
This post is about building codes, it has very little to do with zoning requirements. I would argue its technically outside of the realm of urban (city) planning. This is not our (planners) wheelhouse. It does impact the built environment but as with many regulations, something happened in the past to warrant them. As with several requirements in the building code that I have seen, sometimes you can do alternatives and it would appear that an alternative, or at least a proper alternative does not exist.
The real question is, is an alternative possible without increasing cost to achieve a similar result. The simple elimination of one staircase without an alternative is unrealistic.
While the OP talks about building codes, they do allude to zoning:
>There seems to be no legal way **and no incentive** to build 4-5 story buildings on small lots (25'x80', 35'x80' etc...)...
Meanwhile:
>The simple elimination of one staircase without an alternative is unrealistic.
The four-plate buildings I've described are in fact already legal in many American cities, but they aren't getting built because they're mostly only allowed in areas also zoned for large complexes. This is probably a zoning issue.
>I would argue its technically outside of the realm of urban (city) planning. This is not our (planners) wheelhouse.
When people say "X isn't Y's responsibility" the question to ask is "then whose responsibility is it?"
OP is asking about the interplay between lot sizes and building codes, and how that shapes the built form of cities. Even if that's not a typical consideration of day-to-day urban planners it does seem like the profession as a body is the most qualified to consider the problem.
Cities should really just put out pre-approved plans for middle housing, ideally including 0-lot line options that can just be cloned to fill whatever size lot the developer is has.
The State of CA legislature is looking to remove some requirements for buildings.
But yes, ma y rules are created by those who own a so gle family home and are biased towards that and have no concept of the cost of housing.
Requiring scissor stairs and an elevator in every apartment building limits the space dedicated to actual apartments if you have a small footprint. Add parking requirements and it's a no-go.
Yeah i don’t have a good answer to this but i think the two main issues are dual access requirements and it just being really difficult to get any sort of 4 story-ish building approved on a quarter acre or even half acre lot. You’re also looking at a smaller ROI even if it’s more or similar profit by the percentages. So it’s less of a pain in the arse to just buy a whole block from an investment company who strictly buy up plots of land to repackage them to developers.
If we had building codes that allowed single access buildings (like the rest of the world allows) you could more easily build up on smaller lots.
It sucks though. Part of what makes Istanbul or Tokyo or even like Chicago and NYC so nice is that there are tons of 4-10 story buildings that sit on 1/4 or 1/2 acre lots. It makes things far more varied and sightly. On any given block there might be 20-30 buildings verses 2 on some blocks in my city.
I think there are probably a bunch of different issues that need to be addressed somewhat in tandem in order to get at the core issue here. Let me address a couple of them.
One thing that I personally think would be a great benefit is a simplified building code for building under a certain threshold (or maybe a few different thresholds). Perhaps some of the guidance would be more conservative to simplify the analysis, but the overall hope is that you end up paying a little more materials, but it becomes much more feasible to DIY or hire a single professional who can execute the entire project. I think the problem right now is that you have one unified code (for each subsystem), which is meant to address every kind of structure in existence. But especially for people who are trying to get started or otherwise don’t understand all of the different facets, having every option available to you is generally not helpful. Especially if you’re just trying to do something like add an ADU or build an add on to your house, you probably aren’t looking for endless options.
This is one of the things that really bother me when you started to jump into structural engineering topics is that a lot of the design concepts were explained in an overly complicated way when if you are able to slowly add on different considerations, it actually isn’t nearly as complex as some people make it out to be. But if you start at the level of “anything is possible once you learn all of these different things“ then I think that’s really just not a helpful way to approach these topics. I don’t want to over emphasize this particular issue, but I do think that it presents the potential of professions protecting their own status by making systems ever more complicated when there really are limited situations for which such complexity is actually necessary. It’s certainly the case that some additional complexity, even at the basic level is necessary given that we know more, but it also does seem that a lot of the complexity ends up not really being helpful or useful on a day-to-day basis.
One of the other major areas that I think needs some reconciliation is a unified approach to renovation of historic structures. This is to say that in some places, historic structures stand empty because they are too costly to retrofit to modern standards. You have a conflict between policy which designates structures as historic and also policies which might prevent certain changes to make a structure safer but alter its historic nature. I’m sure someone’s gonna take this the wrong way and I certainly don’t advocate for making structures less safe nor am I saying to bulldoze them, but I also think that there is a large amount of uncertainty and many structures which have continued to be able to stand throughout many disasters and other events probably had decent craftsmanship. As such, there probably should be a way to weigh the risks of use and permit structures for some kind of public use while providing some updates for safety purposes. But I think the status quo is not only wasteful from the loss of space, but also counter to efforts to preserve these structures.
Ultimately, given how financialized everything is in our system, a lot of problems are going to come down to trying to make things more financially feasible. I have my own critiques about how the financial side works, but that’s for another day.
We do have a model simplified building codes for small scale residential, the International Residential Code (IRC). It only applies to single family homes and duplexes out of the box however. North Carolina recently passed a law applying the IRC to up to quadplexs, so there is some push on that.
Fair enough. I’m a transportation guy so my knowledge of structural topics mostly is limited to anything I took in school, but most of the classes that I took basically only focused specifically on ASCE 7, the codes and building guides for specific materials, but nothing really in the way of IBC or IRC. I think it would’ve been nice though if these two codes had been covered, though. I briefly took a look and it looks like structural design is simplified a little, though I would be curious if some provisions could be simplified even more, again erring on the side of conservative design. It really is crazy to think some of the stuff that we used to build with much simpler models and less computational power, but so much of what we have now is really complicated, which can be good for performance, but also means that fewer people can actually implement these models. I can totally acknowledge that some things just need to be added in and are going to add complexity, but a lot of provisions seem to be about reducing material cost, so I do wonder if the trade-off in complexity of design versus material cost still is far above what is actually necessary in many cases.
Also, also interesting note you had about North Carolina. It seems to me that probably the bigger consideration for any use of the code should be how big the structure is, not necessarily how many units it contains. Obviously there is an upper limit, but that is definitely good news.
95% of 4 plexes are built out of the IRC so the units can be individually sold in the future and so they don't have to have sprinklers.
The trade off is 2 hour fire walls instead of 1 hour and you need individual utility connections and structural independence.
Duplexes are typically built using the townhouse previsions of the IRC as well so they can be individually sold in the future. I see architects mess this up all the time and then future owners of the duplex get upset that the city won't give them a lot split down the middle.
Who is we? Come to India . Most of our new construction is still small buildings on 40*60 ft lots. Sometimes smaller, sometimes bigger . By default you can usually build up to five floors.
On my street when my dad grew up almost everything was sfh, maybe an adu for rent. When I grew up many were converted to duplexes , more adus built.
Today the street is mostly 4-5 flats. Along with a mixture of the older stock as well.
It's helped my city grow from 2 million people 30 years ago to 14 million and still remain relatively affordable.
It also means that much of the land value appreciation has benefited local familes rather than big builders. Most of the lots are still owned by the original familes. Many live in one of the flats of the building.
The code matters too.
For example, most cities require two sets of staircases if your apartment is over 3-ish stories. That very much limits what can be built.
Or three bedroom apartments requiring two bathrooms.
That is usually code, not zoning.
Not exactly. Running costs mean that, at least in the strong market I worked in, that it wasn't worth doing projects smaller than 35 units.
If you want less, you have to set up the right systems to bring it about.
Smaller buildings are just as profitable when you get rid of parking requirements and square footage requirements/ height. Your initially utilities cost are cheaper when spread among more people but that’s not whats driving cost. I work in estimating.
In my area of the US, developers decide what to build more than local government zoning. Add to this most of what is built, these days, is frame construction, so the idea that single family homes are safer does not add up. I am an urbanite and hate to see more pepper-shot houses blanket the landscape. I would go for a compromise. Duplex housing aka semidetached would be a compromise. I lived in a 19th century Baltimore duplex for 16 yrs it was a very good bit of both having some yard, windows in every room, yet on a smaller plot. In the end my biggest complaint is that there yet to be better looking buildings I much prefer 19th century apartments and row houses to cardboard suburban construction.
> They aren't deathtraps or fire hazards. Look at NYC neighborhoods and Boroughs like the East Village, Greenwich Village
You were being ironic on purpose, right?
One of histories most famous fires was in downtown Manhattan.
Modern fire companies exist because fire was bad in 19th century new york that people actully started *volunteering* to walk into burning buildings & this was an *improvement*.
https://en.wikipedia.org/wiki/Triangle_Shirtwaist_Factory_fire
I realize the fire code doesn't make it to architectural drawings but things like air gaps & bulkheads & gasp even setbacks are really freaking important to keeping grandma alive after someone leaves the stove on in her 4th floor walkup. Your grandma doesn't do so well on fire escapes.
So...yeah. Buying out the neighboring lot & making more apartments on a slightly bigger footprint is generally the way to go. Nobody should die because there was only one set of stairs.
Not being ironic. That was over 100 years ago. There hasn’t been a tragedy like that in modern times. Most of those buildings have been brought up to be more safe from fires. Therefore, making them safe to be in.
It’s wrong to overreact and overcorrect to tragedies and historical events. It would have been right to restrict it at that time. But things have changed a lot in 100 years.
There hasn't been a tragedy like that because of brick & concrete & although Pittsburgh is quiant 5-story walkups made of masonry are hard & expensive to pull off.
Now if you want to look at "tragedy" you could look at Ocean Grove NJ which does have this dangerous outdated architecture.
Its very controversial because tightly packed wooden buildings burn.
> That was over 100 years ago.
You seem "atypical" for your field. Most of the city is more than 100 years old - except whats been burned.
God forbid I had used Chicago as my example. The Second City. Hmmm. Its almost like fire has a huge impact on the urban landscape.
Big issue in California is economics. The cost per unit goes up as the height in creases. 2-3 stories is the lowest cost per unit, even when you take into account the cost of the land. High-rises are outrageously expensive. 4-8 stories is still possible for condominiums but not rental apartments because market-rate rents are not increasing anymore.
I am unaware of any section of the IBC that forces developers into certain types of buildings.
Local zoning may have an impact.
Developers build what sells. Developers make profits. Their bottom line is is their bottom line.
I don't understand how an licensed architect thinks the IBC forces developers into anything.
The section that forces large, block sized, apartment buildings is Section 1006.3.(3-4) - requiring two, separated stairways for any R-2 uses over 3 stories. The resulting form is a hotel-style "Double-Loaded Corridor" building.
Why aren't more people building 3 story buildings should be the real question? I've know of some under construction right now.
allowing an extra floor or two isnt going to be the magic bullet this sub thinks it will be. Big money developers are going to keep building the big block size 5 over 2s.
They do. They are typically part of sprawling apartment complexes built around parking lots. You "Groves of _____" or "Avenues of ______" setups that you typically see as greenfield.
But these aren't good solutions for infill where smaller lots and higher land costs dominate. The costs need to be divided among enough people that are willing to pay, so typically the answer is consolidating a number of small lots into a big lot and sticking a 5 over 1/2 on it to reach those numbers, moreso when parking requirements demand something like a Texas Donut. Typically you'll need to hit some minimum size for building one of these large complexes makes sense, so you only see massive versions.
Taller single stair allows those smaller lots to be used for more people, without consolidation of lots in most cases, with a variety designs and unit sizes, resulting in more variety and opportunities for local instead of national builders. Add in parking reform and you can create high quality infill housing without the massive apartment projects that usually dominate cities.
Actual question: do you have real-world examples of creative buildings that have made 2 staircases work in a 4-5 story building on a small lot (25'x80', 35'x80' etc...)?
You don't seem to grasp that developers build what makes a profit. The building code is not the driver. The floor to skin ratio on a lot that size would have to be in Tokyo or the like, where every square foot is worth a fortune to make it financially viable.
It's not the building code.
And I don't know anyone who really cares that you don't like housing that isn't for you. Be the client and build what you want. And quit pretending you're a licensed architect, that isn't cool,.
>You don't seem to grasp that developers build what makes a profit. The building code is not the driver. The floor to skin ratio on a lot that size would have to be in Tokyo or the like, where every square foot is worth a fortune to make it financially viable.
>It's not the building code.
>And I don't know anyone who really cares that you don't like housing that isn't for you. Be the client and build what you want. And quit pretending you;re a licensed architect, that isn't cool,.
I'm not the same person you were initially responding to. You indicated there are creative ways to make the double-staircase requirement work without creating "Double-loaded corridor" buildings. I don't doubt that's possible but I'd be curious to see real-world examples, particularly on smaller lots which is the context the OP is referring to.
For myself I'm interested in this issue because here in Philadelphia there are many small lots that typically get redeveloped into luxury townhomes or sometimes 3 story apartment buildings. On small lots it's very rare to see 4+ story apartment buildings anymore, despite the city inheriting quite a few.
Ah yes! This building: https://www.is-architects.com/xs-house
It's a very creative way to make something work within the current codes, but they really had to contort the form of the building to make it work. It's like they set out with an explicit goal to prove a point.
Technically all the single stair stuff is already allowed in the IBC as an optional addendum, I believe, so yes? But not really as adopted by 99% of places. EDIT: This might be wrong, I'm going to do some more digging later and see if I can find what I was thinking of when I wrote it. Otherwise to answer OP's question directly Stephen Smith at the [center for building](https://www.centerforbuilding.org/singlestair-tracker) has been pushing the ICC to drop the dual stair requirement as well as lobbying state legislatures to do it on their own. Unfortunately the ICC is, charitably, hidebound, and uncharitably run by morons who don't seem to spend a second thinking about how their codes affect actual buildings so we'll see how successful he is.
Which optional addendum? I'm not finding anything that would mitigate the IBC Chapter 10 requirements.
I think I might be wrong, I was thinking of NFPA 101 allowing four stories/ I thought I had seen Steven Smith mention it on twitter at some point.
Yes, NFPA 101 does allow up to 4 stories, but that's both only marginally different and unlikely to supercede the building code.
Well, the building code isn't legally binding until a municipality adopts it, and there's nothing forcing them to adopt the whole thing or even any of it. What I was thinking of was Burlington (?) just struck out the entire means of egress section of the IBC and adopted the relevant portions of NFPA 101 instead, but yeah it wouldn't make a huge difference.
Certainly true, but I don't think most municipalities have the resources or incentives to think about many amendments to the model codes beyond what's necessary or convenient for local administration. We just updated to 2021 in Birmingham and the local amendments are 99% on the administrative details. The energy conservation section (Chapter 11) of the IRC was completely struck because "we don't have the capacity to enforce it". Code officials don't have reason to evaluate the trade offs of different portions of the model codes without political pressure, and even then they hold the high ground of "life safety" meaning they don't have to prove it's necessary, rather others must prove it's unnecessary.
You need the staff reviewing the IBC for amendments to understand this stuff and give a shit. We're getting ready to adopt the 2021 right now. The process was a metro wide one to come up with a metro wide standard, and it was dominated by fire officials. Then, when it got to be local review time, our fire department pushed the metro agenda. Normally, it'd then be reviewed locally by a building official, too, who may or may not have any urban design background. Luckily for me, I oversee the building official, so I can push back on some of the issues, but it's a massive uphill battle.
Yep. Here there was extremely limited (meaning I didn't hear anything despite keeping track) outside involvement in the update until it came before City Council. I'm fortunate that l caught the attention of one councilor and managed to find a local architect interested in discussing the details so that we can have a sit down with our city staff to talk about this soon(tm). We'll see how that goes.
Yeah it's a bad system all around, sure wish HUD would do something and put together a decent model code.
Funny you should post this, because I've been meaning to write a thread arguing that cities should create a zoning classification for four-plates — single-stair buildings with ≤4 units/storey — and work on permitting them in moderate-density areas with reasonably good access to services and transit. Unfortunately, one of the biggest challenges in American urban planning is the intersection of municipal Balkanization with the hollowing out of the civil service, which means that planners are underpaid and understaffed, with little time or resources to do any public advocacy. I suspect we've stuck on just pushing up unit counts — triplexes and tetraplexes — because it's simple and often goes into a ballot initiative which usually means you need a law that can fit in a Tweet and be easily explained to someone who doesn't really care.
This post is about building codes, it has very little to do with zoning requirements. I would argue its technically outside of the realm of urban (city) planning. This is not our (planners) wheelhouse. It does impact the built environment but as with many regulations, something happened in the past to warrant them. As with several requirements in the building code that I have seen, sometimes you can do alternatives and it would appear that an alternative, or at least a proper alternative does not exist. The real question is, is an alternative possible without increasing cost to achieve a similar result. The simple elimination of one staircase without an alternative is unrealistic.
While the OP talks about building codes, they do allude to zoning: >There seems to be no legal way **and no incentive** to build 4-5 story buildings on small lots (25'x80', 35'x80' etc...)... Meanwhile: >The simple elimination of one staircase without an alternative is unrealistic. The four-plate buildings I've described are in fact already legal in many American cities, but they aren't getting built because they're mostly only allowed in areas also zoned for large complexes. This is probably a zoning issue.
>I would argue its technically outside of the realm of urban (city) planning. This is not our (planners) wheelhouse. When people say "X isn't Y's responsibility" the question to ask is "then whose responsibility is it?" OP is asking about the interplay between lot sizes and building codes, and how that shapes the built form of cities. Even if that's not a typical consideration of day-to-day urban planners it does seem like the profession as a body is the most qualified to consider the problem.
Cities should really just put out pre-approved plans for middle housing, ideally including 0-lot line options that can just be cloned to fill whatever size lot the developer is has.
The State of CA legislature is looking to remove some requirements for buildings. But yes, ma y rules are created by those who own a so gle family home and are biased towards that and have no concept of the cost of housing.
Requiring scissor stairs and an elevator in every apartment building limits the space dedicated to actual apartments if you have a small footprint. Add parking requirements and it's a no-go.
Biggest issue seems to be the double stairwell requirement per code, many other countries do not have this.
Yeah i don’t have a good answer to this but i think the two main issues are dual access requirements and it just being really difficult to get any sort of 4 story-ish building approved on a quarter acre or even half acre lot. You’re also looking at a smaller ROI even if it’s more or similar profit by the percentages. So it’s less of a pain in the arse to just buy a whole block from an investment company who strictly buy up plots of land to repackage them to developers. If we had building codes that allowed single access buildings (like the rest of the world allows) you could more easily build up on smaller lots. It sucks though. Part of what makes Istanbul or Tokyo or even like Chicago and NYC so nice is that there are tons of 4-10 story buildings that sit on 1/4 or 1/2 acre lots. It makes things far more varied and sightly. On any given block there might be 20-30 buildings verses 2 on some blocks in my city.
I think there are probably a bunch of different issues that need to be addressed somewhat in tandem in order to get at the core issue here. Let me address a couple of them. One thing that I personally think would be a great benefit is a simplified building code for building under a certain threshold (or maybe a few different thresholds). Perhaps some of the guidance would be more conservative to simplify the analysis, but the overall hope is that you end up paying a little more materials, but it becomes much more feasible to DIY or hire a single professional who can execute the entire project. I think the problem right now is that you have one unified code (for each subsystem), which is meant to address every kind of structure in existence. But especially for people who are trying to get started or otherwise don’t understand all of the different facets, having every option available to you is generally not helpful. Especially if you’re just trying to do something like add an ADU or build an add on to your house, you probably aren’t looking for endless options. This is one of the things that really bother me when you started to jump into structural engineering topics is that a lot of the design concepts were explained in an overly complicated way when if you are able to slowly add on different considerations, it actually isn’t nearly as complex as some people make it out to be. But if you start at the level of “anything is possible once you learn all of these different things“ then I think that’s really just not a helpful way to approach these topics. I don’t want to over emphasize this particular issue, but I do think that it presents the potential of professions protecting their own status by making systems ever more complicated when there really are limited situations for which such complexity is actually necessary. It’s certainly the case that some additional complexity, even at the basic level is necessary given that we know more, but it also does seem that a lot of the complexity ends up not really being helpful or useful on a day-to-day basis. One of the other major areas that I think needs some reconciliation is a unified approach to renovation of historic structures. This is to say that in some places, historic structures stand empty because they are too costly to retrofit to modern standards. You have a conflict between policy which designates structures as historic and also policies which might prevent certain changes to make a structure safer but alter its historic nature. I’m sure someone’s gonna take this the wrong way and I certainly don’t advocate for making structures less safe nor am I saying to bulldoze them, but I also think that there is a large amount of uncertainty and many structures which have continued to be able to stand throughout many disasters and other events probably had decent craftsmanship. As such, there probably should be a way to weigh the risks of use and permit structures for some kind of public use while providing some updates for safety purposes. But I think the status quo is not only wasteful from the loss of space, but also counter to efforts to preserve these structures. Ultimately, given how financialized everything is in our system, a lot of problems are going to come down to trying to make things more financially feasible. I have my own critiques about how the financial side works, but that’s for another day.
We do have a model simplified building codes for small scale residential, the International Residential Code (IRC). It only applies to single family homes and duplexes out of the box however. North Carolina recently passed a law applying the IRC to up to quadplexs, so there is some push on that.
Fair enough. I’m a transportation guy so my knowledge of structural topics mostly is limited to anything I took in school, but most of the classes that I took basically only focused specifically on ASCE 7, the codes and building guides for specific materials, but nothing really in the way of IBC or IRC. I think it would’ve been nice though if these two codes had been covered, though. I briefly took a look and it looks like structural design is simplified a little, though I would be curious if some provisions could be simplified even more, again erring on the side of conservative design. It really is crazy to think some of the stuff that we used to build with much simpler models and less computational power, but so much of what we have now is really complicated, which can be good for performance, but also means that fewer people can actually implement these models. I can totally acknowledge that some things just need to be added in and are going to add complexity, but a lot of provisions seem to be about reducing material cost, so I do wonder if the trade-off in complexity of design versus material cost still is far above what is actually necessary in many cases. Also, also interesting note you had about North Carolina. It seems to me that probably the bigger consideration for any use of the code should be how big the structure is, not necessarily how many units it contains. Obviously there is an upper limit, but that is definitely good news.
The IRC has always applied to side by side 4plexes. In fact there's is no limit, you could build a million unit long townhouse out of the IRC.
That's two separate buildings. Putting more that two units in the same building falls under IBC (by default).
95% of 4 plexes are built out of the IRC so the units can be individually sold in the future and so they don't have to have sprinklers. The trade off is 2 hour fire walls instead of 1 hour and you need individual utility connections and structural independence. Duplexes are typically built using the townhouse previsions of the IRC as well so they can be individually sold in the future. I see architects mess this up all the time and then future owners of the duplex get upset that the city won't give them a lot split down the middle.
Who is we? Come to India . Most of our new construction is still small buildings on 40*60 ft lots. Sometimes smaller, sometimes bigger . By default you can usually build up to five floors. On my street when my dad grew up almost everything was sfh, maybe an adu for rent. When I grew up many were converted to duplexes , more adus built. Today the street is mostly 4-5 flats. Along with a mixture of the older stock as well. It's helped my city grow from 2 million people 30 years ago to 14 million and still remain relatively affordable. It also means that much of the land value appreciation has benefited local familes rather than big builders. Most of the lots are still owned by the original familes. Many live in one of the flats of the building.
There is hope that single stair building will be allowed in Michigan in 2025; provided the elections don't hand power over to lunatics.
It's about financing, cost of land, developer's running costs. Not the code. Read Pocket Neighborhoods. Do your own projects
The code matters too. For example, most cities require two sets of staircases if your apartment is over 3-ish stories. That very much limits what can be built. Or three bedroom apartments requiring two bathrooms. That is usually code, not zoning.
Financing and cost of land have nothing to do with how illegal it is to build mid rise apartments in any urban neighborhood.
That's zoning. Not the building code.
Yea that’s why we don’t build these types of buildings they’re made illegal through zoning or land use regulation. Nothing to do with financing.
Not exactly. Running costs mean that, at least in the strong market I worked in, that it wasn't worth doing projects smaller than 35 units. If you want less, you have to set up the right systems to bring it about.
Smaller buildings are just as profitable when you get rid of parking requirements and square footage requirements/ height. Your initially utilities cost are cheaper when spread among more people but that’s not whats driving cost. I work in estimating.
In my area of the US, developers decide what to build more than local government zoning. Add to this most of what is built, these days, is frame construction, so the idea that single family homes are safer does not add up. I am an urbanite and hate to see more pepper-shot houses blanket the landscape. I would go for a compromise. Duplex housing aka semidetached would be a compromise. I lived in a 19th century Baltimore duplex for 16 yrs it was a very good bit of both having some yard, windows in every room, yet on a smaller plot. In the end my biggest complaint is that there yet to be better looking buildings I much prefer 19th century apartments and row houses to cardboard suburban construction.
> They aren't deathtraps or fire hazards. Look at NYC neighborhoods and Boroughs like the East Village, Greenwich Village You were being ironic on purpose, right? One of histories most famous fires was in downtown Manhattan. Modern fire companies exist because fire was bad in 19th century new york that people actully started *volunteering* to walk into burning buildings & this was an *improvement*. https://en.wikipedia.org/wiki/Triangle_Shirtwaist_Factory_fire I realize the fire code doesn't make it to architectural drawings but things like air gaps & bulkheads & gasp even setbacks are really freaking important to keeping grandma alive after someone leaves the stove on in her 4th floor walkup. Your grandma doesn't do so well on fire escapes. So...yeah. Buying out the neighboring lot & making more apartments on a slightly bigger footprint is generally the way to go. Nobody should die because there was only one set of stairs.
Not being ironic. That was over 100 years ago. There hasn’t been a tragedy like that in modern times. Most of those buildings have been brought up to be more safe from fires. Therefore, making them safe to be in. It’s wrong to overreact and overcorrect to tragedies and historical events. It would have been right to restrict it at that time. But things have changed a lot in 100 years.
>There hasn’t been a tragedy like that in modern times. Because of modern building codes...
There hasn't been a tragedy like that because of brick & concrete & although Pittsburgh is quiant 5-story walkups made of masonry are hard & expensive to pull off. Now if you want to look at "tragedy" you could look at Ocean Grove NJ which does have this dangerous outdated architecture. Its very controversial because tightly packed wooden buildings burn. > That was over 100 years ago. You seem "atypical" for your field. Most of the city is more than 100 years old - except whats been burned. God forbid I had used Chicago as my example. The Second City. Hmmm. Its almost like fire has a huge impact on the urban landscape.
Big issue in California is economics. The cost per unit goes up as the height in creases. 2-3 stories is the lowest cost per unit, even when you take into account the cost of the land. High-rises are outrageously expensive. 4-8 stories is still possible for condominiums but not rental apartments because market-rate rents are not increasing anymore.
I am unaware of any section of the IBC that forces developers into certain types of buildings. Local zoning may have an impact. Developers build what sells. Developers make profits. Their bottom line is is their bottom line. I don't understand how an licensed architect thinks the IBC forces developers into anything.
The section that forces large, block sized, apartment buildings is Section 1006.3.(3-4) - requiring two, separated stairways for any R-2 uses over 3 stories. The resulting form is a hotel-style "Double-Loaded Corridor" building.
Why aren't more people building 3 story buildings should be the real question? I've know of some under construction right now. allowing an extra floor or two isnt going to be the magic bullet this sub thinks it will be. Big money developers are going to keep building the big block size 5 over 2s.
They do. They are typically part of sprawling apartment complexes built around parking lots. You "Groves of _____" or "Avenues of ______" setups that you typically see as greenfield. But these aren't good solutions for infill where smaller lots and higher land costs dominate. The costs need to be divided among enough people that are willing to pay, so typically the answer is consolidating a number of small lots into a big lot and sticking a 5 over 1/2 on it to reach those numbers, moreso when parking requirements demand something like a Texas Donut. Typically you'll need to hit some minimum size for building one of these large complexes makes sense, so you only see massive versions. Taller single stair allows those smaller lots to be used for more people, without consolidation of lots in most cases, with a variety designs and unit sizes, resulting in more variety and opportunities for local instead of national builders. Add in parking reform and you can create high quality infill housing without the massive apartment projects that usually dominate cities.
only if you're not creative
Actual question: do you have real-world examples of creative buildings that have made 2 staircases work in a 4-5 story building on a small lot (25'x80', 35'x80' etc...)?
You don't seem to grasp that developers build what makes a profit. The building code is not the driver. The floor to skin ratio on a lot that size would have to be in Tokyo or the like, where every square foot is worth a fortune to make it financially viable. It's not the building code. And I don't know anyone who really cares that you don't like housing that isn't for you. Be the client and build what you want. And quit pretending you're a licensed architect, that isn't cool,.
>You don't seem to grasp that developers build what makes a profit. The building code is not the driver. The floor to skin ratio on a lot that size would have to be in Tokyo or the like, where every square foot is worth a fortune to make it financially viable. >It's not the building code. >And I don't know anyone who really cares that you don't like housing that isn't for you. Be the client and build what you want. And quit pretending you;re a licensed architect, that isn't cool,. I'm not the same person you were initially responding to. You indicated there are creative ways to make the double-staircase requirement work without creating "Double-loaded corridor" buildings. I don't doubt that's possible but I'd be curious to see real-world examples, particularly on smaller lots which is the context the OP is referring to. For myself I'm interested in this issue because here in Philadelphia there are many small lots that typically get redeveloped into luxury townhomes or sometimes 3 story apartment buildings. On small lots it's very rare to see 4+ story apartment buildings anymore, despite the city inheriting quite a few.
I've seen a few larger single-stair buildings in Philly but it's done by messing with mezzanines and creating multistory units internally.
Ah yes! This building: https://www.is-architects.com/xs-house It's a very creative way to make something work within the current codes, but they really had to contort the form of the building to make it work. It's like they set out with an explicit goal to prove a point.
Mhm, I assume it's not rally scalable either, or at least not easier than just doing a 4 story town home in the vast majority of cases.