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> We can, however, apply modern technics and materials when they make sense : insulation, windows, waterways... The article raises an important point that coul

> We can, however, apply modern technics and materials when they make sense : insulation, windows, waterways... The article raises an important point that could be a problem when trying to mix old and new build techniques. When talking about brick walls it says: > One tricky thing with this type of assembly is that while it has performed well historically, it doesn’t necessarily play nice with more modern, energy efficient construction. A solid brick wall was traditionally designed to be exposed on the inside, exposing it to interior heat and allowing it to dry. Adding interior insulation makes the house much more comfortable, but also changes the thermal dynamics, potentially causing freeze/thaw damage in the brick, and allowing moisture to accumulate between the brick and the insulation. This is one of the many details that would need to be worked out for the complete design of the home. You can't simply build something following the examples of a castle or a cathedral, but then add modern insulation, because the insulation won't allow the masonry to breath and dry to both sides, leading to water damage, mold, rot, ... At the end of the day, a badly insulated building can be made to last for ages passively by just making it breath, so the temperature and humidity vary with the weather but are kept in check by passive external factors (e.g. the sun shining on a external wall dries it from the outside). While a well insulated building absolutely needs constant mechanical HVAC with fine tuned control. You can have a well insulated building or a passive building, you can't have both (by the way, the "Passive House TM" insulation standard is a complete misnomer, being that mechanical ventilation is its second biggest tenet).

rebuilder 5y ago
Well yes, but the example house doesn't seem to be all that optimized for energy efficiency. Look at the illustration showing a fireplace located at the end of the house. That's going to waste so much heat compared to a centrally located one. So I'm not sure how much attention was paid to energy efficiency here.
- daydream 5y ago
  I came here looking for a comment like this. A fireplace partially exposed to the exterior (as is common nowadays) is essentially entirely decorative and can actually be a net negative in terms of heating the space. seeing that made me question the practicality of the authors other design choices that I know little about.
Retric 5y ago
Construction seriously depends on location. However, the simplest solution if you want high insulation factors is to have a second air tight structure with an air gap to your brickwork. Just make sure to properly ventilate that air gap. The same approach can then be used on a slate roof. Essentially you end up with a home inside a shell. There are several advantages to such structures such a potentially great sound insulation and aesthetics, but it’s not cheap. Having an essentially air tight structure requires a hvac system to match. A combination of heat exchanger, filter, humidity control, and temperature control let you have a very comfortable environment while still benefiting from significant insulation.
- sbierwagen 5y ago
  >Essentially you end up with a home inside a shell. Which then works against the headline design goal: a house that lasts for 1000 years. How many times would you need to rip down and replace the interior shell? How much more difficult would be demolition if you can't use large equipment and smash the whole lot flat, but instead doing by hand from inside, carefully avoiding damage to the outside shell?
  - Retric 5y ago
    First it’s the system used in the article in part because it’s easy to modify brick structures. Anyway, it depends on your design goals. For a hypothetical 1,000 year home you could have an inner shell of any long lived material including wood which could last that long inside a dry shell as long as you can avoid insect damage. That said, the real trick to a 1,000 year home is making something that people want to actually use for the next thousand years to avoid it getting replaced rather than the weather or minimal maintenance issues. Because frankly that’s the real threat, which suggests going for something interesting might beat pure utility. An ideal location might be enough but a hook like artistic frescos, intricate stonework, unusual architecture, famous occupant etc could also get you over the hump until the buildings age inherently becomes a draw. PS: Don’t forget flexibility needs to be part of the design. Electricity, central heating, phone service, AC, and eventually the internet are all relatively recent inventions. I can only assume plenty more systems are going to become normal in the next 1,000 years.
downrightmike 5y ago
Mortar holding stones from even Roman times, is still wet in the middle.
drewzero1 5y ago
A lesson I've been repeatedly learning since buying an old house, is that many design decisions that seem dumb now were actually optimized very well for what was available at the time. It can be a real challenge to try to retrofit modern efficiency and comfort into a home that was designed for constraints and expectations of another time. We recently replaced our furnace and found the footprint of the original coal-fired "octopus" gravity furnace, and learning about the operation of the old furnace makes the seemingly inadequate ductwork make more sense. Instead of a furnace blower (which hadn't been introduced yet at the time the house was built) the air moved around the house by convection and relied on a temperature differential between the center of the house and the outside walls. Hot air came up a few ducts in the middle of the house, and cold air came down through return ducts on the outside walls. Unfortunately the chimney was also acting as a radiant heating element, and one of the upstairs bedrooms has become much colder since switching to the higher-efficiency furnace (which scavenges much more heat from the exhaust, and vents out the side of the house). Ultimately I'm sure the much more efficient furnace will be worth it, but there are trade-offs that will need to be addressed.
ozim 5y ago
My pet peeve is when people claim that heavy old cast iron radiators are "always better" than new flimsy steel ones. Yes those are better for old houses with old insulation or no insulation because then you wanted radiator to keep warm so you can sit close to it and get yourself warm. Where with new thing ones you want to heat up the air so you don't want radiator to be warm but air in well insulated building.
- littlestymaar 5y ago
  > here with new thing ones you want to heat up the air so you don't want radiator to be warm but air in well insulated building. This is more complicated than this, and the construction industry has actually gone back and forth on this topic for the past 40 years. A few consideration against your point: - When you heat air, you dry it up, which can be pretty uncomfortable for the inhabitants. - Air stratification is a big concern: when you heat air up, it raises up to the ceiling, warming nobody but the spiders in the corners. It's not uncommon to have a multiple Celsius degree difference between floor and ceiling, even in an air-tight room. - A house cannot be air-tight because you need to bring new air for breathing, but also to avoid excess moisture in wet rooms, which means your precious warmed-up air is being vented away, and you bring cold air from outside instead. There exists sophisticated systems with heat exchangers to collect heat from the outgoing air and warm the incoming air, but those are really expensive and far from ubiquitous. - Under standard conditions, thermal comfort comes in roughly equal part from the radiative flux (from the walls) and conduction/convection (from the air) one. So you can achieve a similar level of comfort with lower air temperature when you have a warm radiative surface in a room. At the end of the day, old cast-iron radiators are pretty good from a heating standpoint. (But they have multiple drawbacks, like being really big, and so heavy you can't move them when you want to refresh the room paint, etc. which means that nowadays, people usually prefer underfloor heating instead)
  - ozim 5y ago
    Yes that is what I am describing as well - that it is more complicated. I am not saying that new steel radiators are somehow superior.
  - 5y ago

rebuilder 5y ago

Well yes, but the example house doesn't seem to be all that optimized for energy efficiency. Look at the illustration showing a fireplace located at the end of the house. That's going to waste so much heat compared to a centrally located one. So I'm not sure how much attention was paid to energy efficiency here.

daydream 5y ago
I came here looking for a comment like this. A fireplace partially exposed to the exterior (as is common nowadays) is essentially entirely decorative and can actually be a net negative in terms of heating the space. seeing that made me question the practicality of the authors other design choices that I know little about.

Retric 5y ago

Construction seriously depends on location. However, the simplest solution if you want high insulation factors is to have a second air tight structure with an air gap to your brickwork. Just make sure to properly ventilate that air gap. The same approach can then be used on a slate roof. Essentially you end up with a home inside a shell. There are several advantages to such structures such a potentially great sound insulation and aesthetics, but it’s not cheap. Having an essentially air tight structure requires a hvac system to match. A combination of heat exchanger, filter, humidity control, and temperature control let you have a very comfortable environment while still benefiting from significant insulation.

sbierwagen 5y ago
>Essentially you end up with a home inside a shell. Which then works against the headline design goal: a house that lasts for 1000 years. How many times would you need to rip down and replace the interior shell? How much more difficult would be demolition if you can't use large equipment and smash the whole lot flat, but instead doing by hand from inside, carefully avoiding damage to the outside shell?
- Retric 5y ago
  First it’s the system used in the article in part because it’s easy to modify brick structures. Anyway, it depends on your design goals. For a hypothetical 1,000 year home you could have an inner shell of any long lived material including wood which could last that long inside a dry shell as long as you can avoid insect damage. That said, the real trick to a 1,000 year home is making something that people want to actually use for the next thousand years to avoid it getting replaced rather than the weather or minimal maintenance issues. Because frankly that’s the real threat, which suggests going for something interesting might beat pure utility. An ideal location might be enough but a hook like artistic frescos, intricate stonework, unusual architecture, famous occupant etc could also get you over the hump until the buildings age inherently becomes a draw. PS: Don’t forget flexibility needs to be part of the design. Electricity, central heating, phone service, AC, and eventually the internet are all relatively recent inventions. I can only assume plenty more systems are going to become normal in the next 1,000 years.

downrightmike 5y ago

Mortar holding stones from even Roman times, is still wet in the middle.

drewzero1 5y ago

A lesson I've been repeatedly learning since buying an old house, is that many design decisions that seem dumb now were actually optimized very well for what was available at the time. It can be a real challenge to try to retrofit modern efficiency and comfort into a home that was designed for constraints and expectations of another time. We recently replaced our furnace and found the footprint of the original coal-fired "octopus" gravity furnace, and learning about the operation of the old furnace makes the seemingly inadequate ductwork make more sense. Instead of a furnace blower (which hadn't been introduced yet at the time the house was built) the air moved around the house by convection and relied on a temperature differential between the center of the house and the outside walls. Hot air came up a few ducts in the middle of the house, and cold air came down through return ducts on the outside walls. Unfortunately the chimney was also acting as a radiant heating element, and one of the upstairs bedrooms has become much colder since switching to the higher-efficiency furnace (which scavenges much more heat from the exhaust, and vents out the side of the house). Ultimately I'm sure the much more efficient furnace will be worth it, but there are trade-offs that will need to be addressed.

ozim 5y ago

My pet peeve is when people claim that heavy old cast iron radiators are "always better" than new flimsy steel ones. Yes those are better for old houses with old insulation or no insulation because then you wanted radiator to keep warm so you can sit close to it and get yourself warm. Where with new thing ones you want to heat up the air so you don't want radiator to be warm but air in well insulated building.

littlestymaar 5y ago
> here with new thing ones you want to heat up the air so you don't want radiator to be warm but air in well insulated building. This is more complicated than this, and the construction industry has actually gone back and forth on this topic for the past 40 years. A few consideration against your point: - When you heat air, you dry it up, which can be pretty uncomfortable for the inhabitants. - Air stratification is a big concern: when you heat air up, it raises up to the ceiling, warming nobody but the spiders in the corners. It's not uncommon to have a multiple Celsius degree difference between floor and ceiling, even in an air-tight room. - A house cannot be air-tight because you need to bring new air for breathing, but also to avoid excess moisture in wet rooms, which means your precious warmed-up air is being vented away, and you bring cold air from outside instead. There exists sophisticated systems with heat exchangers to collect heat from the outgoing air and warm the incoming air, but those are really expensive and far from ubiquitous. - Under standard conditions, thermal comfort comes in roughly equal part from the radiative flux (from the walls) and conduction/convection (from the air) one. So you can achieve a similar level of comfort with lower air temperature when you have a warm radiative surface in a room. At the end of the day, old cast-iron radiators are pretty good from a heating standpoint. (But they have multiple drawbacks, like being really big, and so heavy you can't move them when you want to refresh the room paint, etc. which means that nowadays, people usually prefer underfloor heating instead)
- ozim 5y ago
  Yes that is what I am describing as well - that it is more complicated. I am not saying that new steel radiators are somehow superior.
- 5y ago