Thanks Brian. I especially appreciate the break down on the statistics related to the destruction of buildings. We're pretty good at accident prevention, but media reports will fixate on the few thousand homes eliminated by natural disasters vs. the hundreds of thousands that are demolished voluntarily.
Since you're last post I've been trying to think of real world examples of 500 year old dwellings that have a high probability of being occupied for another 500 years. I think that many of the "upper middle class" villas in Tuscany and other Mediterranean locations have architecture suited to longevity. The construction type consists of masonry bearing walls, timber floor and roof framing, and tile or slate roofs. Positive features include decent room proportions, high ceilings, and good natural light. A pain to renovate initially, but once you've established modern utilities you can repair them without tearing apart bearing walls.
The construction methods you describe are most consistent with what the Unity Homes branch of Bensonwood has been doing for more than a decade. I'm impressed by their solutions but skeptical of them as a platform that could be replicated successfully. The verdict is still out on the American stick-framing revolution. Our current demolition rate implies that every dwelling built in the 20th century suburban housing boom will be gone by the end of this century--or the middle of the next one.
I wonder what it takes to make a really large building culturally valuable enough to retain for 1000 years. Are the Empire State Building or the Pentagon examples of that? Probably not, but what would be?
Sounds like an earth-berm, monolithic dome home is the way to go. Protected by earth itself underground removes most of the environmental damage, assuming adequate drainage and moisture control. Domes are basically the strongest structure. Boom.
Hi Brian, I didn't know how to reach out to you, but I wanted to propose a future post that I would be very interested in: Why don't we see more vertical upgrading of houses? I am an economist partly interested in housing economics. There is always a lot of talk about zoning restrictions and housing regulations that prevent more house building. Often, the focus is on new buildings. But it seems to me that there is also a technical bottleneck for why there is not more "adding additional floors to houses". On the surface, it seems like an easy short-term fix for low housing supply: just add cheap additional floors on existing housing stock and make these upgrades financially lucrative to house owners. I live in Toulouse, France, and I am always amazed that there are many 1-floor houses next to 3-floor houses even in the city centre. My prior would be that its technically not easy (depending on housing type), that there is a lot of neighborhood opposition to this (its loud) and that there are housing regulations that prevent some of it. I am sorry if I missed a previous post of you that touches on this issue.
I'm not Brian, but maybe as an architect specializing in single-family renovation my perspective will be valuable as well. Almost regardless of house type and building technology, adding a floor or two is no technical challenge. Even if existing foundations can't handle the additional load, it's comparatively simple to add posts down to new footings.
The primary objection is from homeowners themselves and from neighborhoods, but it's not "practical", it's aesthetic and social. A primary problem here is that housing availability isn't just about raw sq footage, but how it's divided up. Houses are generally for individual families, and while sq ft or sq meter per person has increased a lot, family size has shrunk. So adding a floor may create more space for an individual family, but it doesn't add to housing stock.
You could add enough space to create a two-family house from a single-family one, or even split into three or more flats, but then you've fundamentally altered the house type. While it's physically practical to add vertically to any type of house, there are very few single family typologies (or individual examples within them) that can handle that sort of addition without the house's identity being utterly destroyed.
House types are defined by certain combinations of specific traits which evolved or were designed along with the type, so that each type is cohesive and recognizable. If your changes are significant enough to break that composition the house is left looking and feeling totally different. If you haven't successfully crafted a new identity for it, it's now neither fish nor fowl and looks and feels awkward and haphazard. Most people with any discretion don't want to live in such a place and are aware that creating one isn't a great investment.
Proportion and massing are hugely definitive elements of such styles. Many such as MCM, Cape Cod, Split-level, and Craftsman, for example, are defined by horizontality. You can certainly make a 3 or even 4 story Craftsman, but you have to start that way. It's often possible, if you're willing to spend significant money, to change a horizontal type into a more vertical type - the right Craftsman can become a credible Salt Box or Foursquare. But that's expensive and won't always work; and even types that are more upright like the Row House or Victorian have their limits.
You say "make these upgrades financially lucrative to house owners", but that's very difficult when the "upgrade" will almost inherently result in more space that's less attractive by its nature. Even worse, the additional space degrades the existing space. None of that space is now as valuable to many people who have a choice.
This is why we tend to see "pop-ups" in lower-wealth neighborhoods: those who can afford to will almost always choose a more elegant solution. They'll knock down and rebuild new, and they're unlikely to add stock: they're probably just after more space for their own family. The value threshold is very high to make it economically worthwhile to replace an existing single family home with a multi-family one. So those pop-ups are occupied and usually owned by those at the lowest socio-economic tiers.
More troubling than all this is that such insensitive expansions impact the neighborhood. Neighborhoods should grow and change, and NIMBYism is a real problem, but in order to continue being vibrant and healthy places, desirable places, they need to change organically and usually slowly. If you live in a picturesque neighborhood of Craftmans it doesn't take many cheap blocky pop-ups to make the whole area feel discontinuous and slummy, or many overblown McMansions to make it feel tawdry and superficial. The track-record of rapid neighborhood revolution is not great, and shows that neighborhood collapse is much more likely than with more measured growth. The noise is not the issue.
Hi Nathan, these points are great and super interesting, thank you so much. A couple of discussion points:
1. I was really thinking dense urban places where single-family homes are the rare exception. So my example of 1-floor houses being upgraded to 3-floor houses was badly chosen. Rather think 5-floor to 7-floor house upgrades. Now, I am wondering whether your points on these upgrades changing the fundamental “house type” still applies? I was completely ignorant about the house-type point so I found this very intriguing.
2. Related to this, I am a bit more sceptical about your point on such housing upgrades changing the identity of the house to the extent that people don’t want to live there anymore. When thinking about dense urban city parts, I think people have a strong preference for the local neighbourhood to live in as well as the interior standard of housing, but less so for the exact exterior housing style of their own house. E.g. people might like to live in Paris’ 5th Arrondissement because of its charm, but they care less about the exact house they live in (as long as neighbouring houses and streets are nice from the exterior). So the charm of the local neighbourhood is an externality that local house owners are unlikely to take into account when considering floor-upgrades to their own houses. And even if upgrades diminish the value of existing flats in the house, it would be simple for the house owner to just lower rents slightly for incumbent tenants if they have the chance to add many more flats. So why don't we see more of it (even if it is harmful in some of the ways you say it is)? Is this just housing restrictions?
3. I am very curious about your architectural point-of-view on why there is not more innovation to let upgrades look fantastic? I can definitely buy the argument that upgrades change the feeling for the house and that they may decrease the value of the house or that city bureaucracies oppose these as they lower the value of the entire neighbourhood, but I can think of many reasons for why upgrades could also look great and while changing the feeling for the neighbourhood, could actually improve neighbourhoods. Given the huge returns to such innovation (rents and house prices are incredibly high in most dense cities), why don’t we see more of it? And do you really think there is a natural limit to how nice upgraded houses can look? (Related to this, could you maybe provide a reference for failed rapid neighborhood revolutions? I would be very interested in this).
Your analysis seems sound, but I think it misses a major issue.
Being "built to last for 1000 years" is actually an anti-feature for many actors in the political economy. Forces that want more housing supply care much more about low cost than 1000 year life span. Government doesn't really want 1000 year lifespans, because at least in the US the ability of government to apply retroactive rules is very limited - if very many houses will last 1000 years it becomes very difficult (impossible) to force all housing to be carbon neutral, bird friendly, <insert whatever cause you want here>. In addition at least in WA state permit fees are a big part of local government revenues, and so a town full of "forever" houses may not be economically viable.
Most buyers have no interest in it, since they won't live to benefit from it, and that will be true for generations of future buyers so it's essentially impossible to monetize.
And in many of the most intense markets (the ones suffering badly from the lack of learning curves and scales of efficiency that you describe so well) - it is simply not possible for a house to be acceptable for 1000 years. The desire to forcibly turn it into some kind of apartment (say) may be overwhelming. In some other "intense" markets (like my waterfront house) the parties that buy such houses often wish to replace them for entirely "personal expression" reasons ("MY awesome lake house, not HIS old lake house") [You talked about value changes, but personal glory changes are a thing too.]
In short, basically nobody views 1000 year life spans for houses as a feature.
Thanks Brian. I especially appreciate the break down on the statistics related to the destruction of buildings. We're pretty good at accident prevention, but media reports will fixate on the few thousand homes eliminated by natural disasters vs. the hundreds of thousands that are demolished voluntarily.
Since you're last post I've been trying to think of real world examples of 500 year old dwellings that have a high probability of being occupied for another 500 years. I think that many of the "upper middle class" villas in Tuscany and other Mediterranean locations have architecture suited to longevity. The construction type consists of masonry bearing walls, timber floor and roof framing, and tile or slate roofs. Positive features include decent room proportions, high ceilings, and good natural light. A pain to renovate initially, but once you've established modern utilities you can repair them without tearing apart bearing walls.
The construction methods you describe are most consistent with what the Unity Homes branch of Bensonwood has been doing for more than a decade. I'm impressed by their solutions but skeptical of them as a platform that could be replicated successfully. The verdict is still out on the American stick-framing revolution. Our current demolition rate implies that every dwelling built in the 20th century suburban housing boom will be gone by the end of this century--or the middle of the next one.
I wonder what it takes to make a really large building culturally valuable enough to retain for 1000 years. Are the Empire State Building or the Pentagon examples of that? Probably not, but what would be?
Neat! Material cost and georisk factors - earthquakes, hillside erosion, average rainfall - can play a big part too!
Sounds like an earth-berm, monolithic dome home is the way to go. Protected by earth itself underground removes most of the environmental damage, assuming adequate drainage and moisture control. Domes are basically the strongest structure. Boom.
Hi Brian, I didn't know how to reach out to you, but I wanted to propose a future post that I would be very interested in: Why don't we see more vertical upgrading of houses? I am an economist partly interested in housing economics. There is always a lot of talk about zoning restrictions and housing regulations that prevent more house building. Often, the focus is on new buildings. But it seems to me that there is also a technical bottleneck for why there is not more "adding additional floors to houses". On the surface, it seems like an easy short-term fix for low housing supply: just add cheap additional floors on existing housing stock and make these upgrades financially lucrative to house owners. I live in Toulouse, France, and I am always amazed that there are many 1-floor houses next to 3-floor houses even in the city centre. My prior would be that its technically not easy (depending on housing type), that there is a lot of neighborhood opposition to this (its loud) and that there are housing regulations that prevent some of it. I am sorry if I missed a previous post of you that touches on this issue.
I'm not Brian, but maybe as an architect specializing in single-family renovation my perspective will be valuable as well. Almost regardless of house type and building technology, adding a floor or two is no technical challenge. Even if existing foundations can't handle the additional load, it's comparatively simple to add posts down to new footings.
The primary objection is from homeowners themselves and from neighborhoods, but it's not "practical", it's aesthetic and social. A primary problem here is that housing availability isn't just about raw sq footage, but how it's divided up. Houses are generally for individual families, and while sq ft or sq meter per person has increased a lot, family size has shrunk. So adding a floor may create more space for an individual family, but it doesn't add to housing stock.
You could add enough space to create a two-family house from a single-family one, or even split into three or more flats, but then you've fundamentally altered the house type. While it's physically practical to add vertically to any type of house, there are very few single family typologies (or individual examples within them) that can handle that sort of addition without the house's identity being utterly destroyed.
House types are defined by certain combinations of specific traits which evolved or were designed along with the type, so that each type is cohesive and recognizable. If your changes are significant enough to break that composition the house is left looking and feeling totally different. If you haven't successfully crafted a new identity for it, it's now neither fish nor fowl and looks and feels awkward and haphazard. Most people with any discretion don't want to live in such a place and are aware that creating one isn't a great investment.
Proportion and massing are hugely definitive elements of such styles. Many such as MCM, Cape Cod, Split-level, and Craftsman, for example, are defined by horizontality. You can certainly make a 3 or even 4 story Craftsman, but you have to start that way. It's often possible, if you're willing to spend significant money, to change a horizontal type into a more vertical type - the right Craftsman can become a credible Salt Box or Foursquare. But that's expensive and won't always work; and even types that are more upright like the Row House or Victorian have their limits.
You say "make these upgrades financially lucrative to house owners", but that's very difficult when the "upgrade" will almost inherently result in more space that's less attractive by its nature. Even worse, the additional space degrades the existing space. None of that space is now as valuable to many people who have a choice.
This is why we tend to see "pop-ups" in lower-wealth neighborhoods: those who can afford to will almost always choose a more elegant solution. They'll knock down and rebuild new, and they're unlikely to add stock: they're probably just after more space for their own family. The value threshold is very high to make it economically worthwhile to replace an existing single family home with a multi-family one. So those pop-ups are occupied and usually owned by those at the lowest socio-economic tiers.
More troubling than all this is that such insensitive expansions impact the neighborhood. Neighborhoods should grow and change, and NIMBYism is a real problem, but in order to continue being vibrant and healthy places, desirable places, they need to change organically and usually slowly. If you live in a picturesque neighborhood of Craftmans it doesn't take many cheap blocky pop-ups to make the whole area feel discontinuous and slummy, or many overblown McMansions to make it feel tawdry and superficial. The track-record of rapid neighborhood revolution is not great, and shows that neighborhood collapse is much more likely than with more measured growth. The noise is not the issue.
Hi Nathan, these points are great and super interesting, thank you so much. A couple of discussion points:
1. I was really thinking dense urban places where single-family homes are the rare exception. So my example of 1-floor houses being upgraded to 3-floor houses was badly chosen. Rather think 5-floor to 7-floor house upgrades. Now, I am wondering whether your points on these upgrades changing the fundamental “house type” still applies? I was completely ignorant about the house-type point so I found this very intriguing.
2. Related to this, I am a bit more sceptical about your point on such housing upgrades changing the identity of the house to the extent that people don’t want to live there anymore. When thinking about dense urban city parts, I think people have a strong preference for the local neighbourhood to live in as well as the interior standard of housing, but less so for the exact exterior housing style of their own house. E.g. people might like to live in Paris’ 5th Arrondissement because of its charm, but they care less about the exact house they live in (as long as neighbouring houses and streets are nice from the exterior). So the charm of the local neighbourhood is an externality that local house owners are unlikely to take into account when considering floor-upgrades to their own houses. And even if upgrades diminish the value of existing flats in the house, it would be simple for the house owner to just lower rents slightly for incumbent tenants if they have the chance to add many more flats. So why don't we see more of it (even if it is harmful in some of the ways you say it is)? Is this just housing restrictions?
3. I am very curious about your architectural point-of-view on why there is not more innovation to let upgrades look fantastic? I can definitely buy the argument that upgrades change the feeling for the house and that they may decrease the value of the house or that city bureaucracies oppose these as they lower the value of the entire neighbourhood, but I can think of many reasons for why upgrades could also look great and while changing the feeling for the neighbourhood, could actually improve neighbourhoods. Given the huge returns to such innovation (rents and house prices are incredibly high in most dense cities), why don’t we see more of it? And do you really think there is a natural limit to how nice upgraded houses can look? (Related to this, could you maybe provide a reference for failed rapid neighborhood revolutions? I would be very interested in this).
Your analysis seems sound, but I think it misses a major issue.
Being "built to last for 1000 years" is actually an anti-feature for many actors in the political economy. Forces that want more housing supply care much more about low cost than 1000 year life span. Government doesn't really want 1000 year lifespans, because at least in the US the ability of government to apply retroactive rules is very limited - if very many houses will last 1000 years it becomes very difficult (impossible) to force all housing to be carbon neutral, bird friendly, <insert whatever cause you want here>. In addition at least in WA state permit fees are a big part of local government revenues, and so a town full of "forever" houses may not be economically viable.
Most buyers have no interest in it, since they won't live to benefit from it, and that will be true for generations of future buyers so it's essentially impossible to monetize.
And in many of the most intense markets (the ones suffering badly from the lack of learning curves and scales of efficiency that you describe so well) - it is simply not possible for a house to be acceptable for 1000 years. The desire to forcibly turn it into some kind of apartment (say) may be overwhelming. In some other "intense" markets (like my waterfront house) the parties that buy such houses often wish to replace them for entirely "personal expression" reasons ("MY awesome lake house, not HIS old lake house") [You talked about value changes, but personal glory changes are a thing too.]
In short, basically nobody views 1000 year life spans for houses as a feature.
Good insights Brian, looking forward to the conclusion in Part 3.
Excited for part 3, I want to see what this thing will look like!
Maybe it can store or be near the Long Now clock