DarkRange55
I am Skynet
- Oct 15, 2023
- 1,868
I would say buildings can last indefinite depending on the amount of maintenance is done and the amount of capital spent on a building to keep it habitable.
I've heard the lifespan of a concrete structure is 50-100 years. But if you properly maintain them, especially the outside, then it increases the longevity. Precast slabs have joints that need to be re-sealed and caulked to prevent water entering. It's really the concern about the rebar and post tensioning cables rusting. Rust is especially prevalent if salt is present. Rust takes more space than the steel it comes from, so rusting rebar can crack concrete.
Cracks in concrete aren'y usually a problem. It's when you notice movement that you want to call a structural engineer to check. Concrete doesn't have much elasticity but it has all the supporting rebar. The compression and tension. The rebar can rust out if moisture gets in through the cracks and you don't take care of them. Occasional leaks through cracks in concrete inside a building is okay if the cracks were already there before thats why the water is flowing that way. If it's outside it can be bad because then it can freeze and expand.
I don't think (this is a bit speculative) that buildings are engineered just to last 50-100 years with the idea that, "hey after 50 years you're tearing it down and putting a new building in its place." But rather built with that lifespan for investors to know, "hey I've got 50 years of capital free investment into my building and I can get a X amount of return before I will need to look at reinvesting in structural repairs." I would say the lifespan (again speculative) has more to do with documentation and planning from an investment perspective than from an engineering and how the building will hold up perspective.
Only rarely should a building fail or need major repairs before its listed lifespan, but after 1.5 lifespans repairs become much more acceptable. Even shoddy Soviet concrete lasts 50 to 100 years in most cases, and well-built, well-maintained 1st-world concrete should last considerably longer.
Brick homes from what I can read have a lifespan of 100-150 years but the US has a tone of examples where they are much older than that with the oldest in the US being built in 1665 (Bacon Castle in Virginia). If brick is on a solid foundation that goes well below the frost line, and if the mortar is kept in good shape, there is no reason brick should fail short of an earthquake.
Yeah in a nutshell, I think that would be a fair assessment of Building worth and ROI, some other factors are: is my building the best size for my lot or can I build bigger to maximize my usage? Is it historical to where ROI might be excluded and your forced to maintain? Can I convert the structure to something more cost effective?
We have also never been able to build these big buildings in humanity before so we might see something completely different in 50-100 years too. I think, "man, imagine if a skyscraper in New York City needed to be demolished right on times square because end of life is up, how would you even begin to accomplish that safely?" Would you still need to keep a building up regardless of ROI because the task is too monumental and not feasible ?
Controlled demolition is pretty impressive, but some buildings are so tall/narrow that I also wonder if disassembly will be needed.
Usually, I am less worried about the condition of mechanical and electrical components, as these are typically maintained in working condition. I tend to worry more about buildings around 50 years old (and older) and specifically about passive assets such as roofs, drain and domestic plumbing, fire suppression water pipe and valves, and as things get really old, then we think about wiring (buildings built that long ago never expected to have the electrical loads that technology brought us over the last few decades).
In Hawaii for example, the galvanized steel on the rooftop ductwork rusted out after only 5 years due to the salty air.
When you start needing foundational repairs to an existing building, it might be time to look at building a new building. But you may not be able to because of restrictions on historical designations. They bought it because they got tax breaks but now they're stuck with it.
You shouldn't have any structural or foundation damage even after 100 years as long as the rebar isn't exposed. After 50 years all the mechanical systems will probably be at the end of their lifecycle and maintenance will get more expensive.
But the Empire State building is still around. Steel buildings are encased for fireproofing and to prevent rust and concrete lasts a long time.
Lifespan before gutting a building: depends on materials, location- tornados, earthquakes, land movement. I remember one property had a water table underneath it so they built giant ball bearing rollers for movement. You try to renovate to minimize the need to tear it down but sometimes you have to decide if keeping it for the historical value is worth it because sometimes it becomes cheaper just to knock it down.
https://en.wikipedia.org/wiki/Seismic_base_isolation
Plumbing lifespan: Many variables. What type of pipe. Depends on whats going through it. Depends on water quality, whats going down it, chemicals, are there restaurants, where in the building, where geographically, is it cast iron or plastic, etc, etc. In Florida cast iron may only last 25 years because of snow birds, that causes it to expand and contract and flake off and solidify and hot and cold weather can do that too and dumping hot water down it.
For sprinkler heads:
Steel, not cast iron because you can screw it together and the water pressure. Whenever they do major construction they need to drain the system incase someone breaks a head.
They use foam now instead of halon because it's toxic. Server rooms have that. Sprinklers weren't required before the 1970's in the US.
Some houses that are new and super close together require it and duplex and up require it
Life is 50 years then either replace or retrograde.
Black pipe is usually used for gas. Galvanized stainless steel for water has been around for a very long time and is still used today. That lasts maybe 50 years. PVC has different grades, so do copper pipes. Steel and metal before the 1970's was mainly sourced from the US and it had a higher mineral content so it would last longer than the stuff from overseas. The pipe's wall thickness also shrank in some cases, to save money. One old property still had some clay pipes. Companies have developed liners for pipes so that they don't necessarily have to remove everything.
In Canada sprinkler every single fire sprinkler head has to be replaced every 25 years. And every 50 years in the US.
It depends on the age and condition of the building, how many times it's been renovated, what upgrades you've done, how well its maintained, how much capital you've reinvested back into it, level of amenities and market type, depends on the quality, consistency and skill of the maintenance workers and their PM's, insulation, age and efficiency of mechanical equipment such as elevators, HVAC etc. all those equations but generally older buildings have a higher operating cost mainly because the older properties have more maintenance like for example your $200,000 boiler breaks that costs a lot to replace it, you're 25 year old roof needs to be replaced and your elevators are well beyond their service life followed by the exterior and then the interior then the old equipment. Sometimes you spend more keeping an old piece of machinery running than you do buying a new one.You get to the point where you start replacing parts instead of the actual equipment. As a building ages, mechanical parts can become discontinued (they don't make them anymore). You need to renovate. And if you don't renovate, you need to modify. Japanese pipes use a different measurement system than American pipes. So, to add an American pipe onto a Japanese one you need special fittings. So, you modify the old system with a new one since they don't make obsolete parts anymore. If the part isn't available, it's very expensive so you may as well renovate and upgrade to a more efficient system.
As for forecasting the engineering budget, my understanding is the monetary rate increases in maintaining a building: all companies have analysts that have different formulas. It's very heavily tied to inflation and the economy. Big companies like say Hilton or Hyatt can take comprehensive formulas and small companies have individual formulas. Big companies will look at their contractors, say Otis has elevator contracts with 200 Hyatt properties and then another company does another. They will look at those contracts and properties that year and figure out how much the increase will be for growth, parts, etc.
For capex, Hyatt has a formula. For front of house, it goes off historical data gathered through PM logs. Supposed to gut the rooms down to the cement every ten years and redesign them and put in new doors and even new AC units if ownership can (but the actual FCU likely goes when the building is demolished). Every 5-6 years you're supposed to do a light remodel so that's drapes, wallpaper, carpet, etc. So, at minimum you should be doing that. Because carpet after ten years is awful from all the tread. Back of house goes off manufacture recommendations. So, gaskets, bearings, motors its of many windings or when the bearing needs to be replaced. Eventually it all needs to be replaced. Piping that is exposed to a lot of acidic substances like chlorine (pools), fruit juice from a bar getting dumped down the drain all the time will corrode a lot faster. CPCV is a much stronger, chemically resistant plastic pipe compared to PVC.
But generally, the cost of maintenance goes up with the rate of inflation. Also, as the building gets older there's more wear and tear, so more maintenance is required and parts become less available, so repairs become more labor intensive. Elevators are probably the most expensive item in a high-rise. It's well over a million dollars to replace them. Elevator maintenance cost goes up by about 5% a year. Elevator mechanics charge very high amounts per hour. Also Fire Life Safety Systems also have extremely costly maintenance. Otherwise, everyone else (maintenance cost increases) just tracks inflation and the economy. With renovations regarding mechanical rooms, there is a life cycle expectancy from the manufacturer for every piece of equipment. Ownership can pushback sometimes, if you can replace parts then you don't need to order new equipment. A lot of times it can be put off until a major overhaul is needed like every 25 years or so.
The cost of maintenance & repair and the price of rooms is always moving further apart in opposite directions. So, ownership must renovate lightly every 3-5 years and major every 7-10. Investment in the property is so important and it's why the now century old Fairmont Hotel in Seattle can charge $200 more per room after their major renovation (down to the studs). The value of the room/property needs to exceed the price.
Thats also why PM preventative maintenance is so important. The lobby carpet gets replaced the most often because it has the most tread. So, if people associate the old carpet in the lobby with the rooms, even though its separate, its psychological and can bring down the perceived value of the hotel.
Expectation to grow profits, but the amount is highly variable. It's based on the NOI (debt servicing), the fixed costs of ownership like insurance, debt, labor, etc. People and debt are the two biggest expenses. A myriad of factors are at play… including the structure of how much return on investment and flow owners require from operations.
I've heard the lifespan of a concrete structure is 50-100 years. But if you properly maintain them, especially the outside, then it increases the longevity. Precast slabs have joints that need to be re-sealed and caulked to prevent water entering. It's really the concern about the rebar and post tensioning cables rusting. Rust is especially prevalent if salt is present. Rust takes more space than the steel it comes from, so rusting rebar can crack concrete.
Cracks in concrete aren'y usually a problem. It's when you notice movement that you want to call a structural engineer to check. Concrete doesn't have much elasticity but it has all the supporting rebar. The compression and tension. The rebar can rust out if moisture gets in through the cracks and you don't take care of them. Occasional leaks through cracks in concrete inside a building is okay if the cracks were already there before thats why the water is flowing that way. If it's outside it can be bad because then it can freeze and expand.
I don't think (this is a bit speculative) that buildings are engineered just to last 50-100 years with the idea that, "hey after 50 years you're tearing it down and putting a new building in its place." But rather built with that lifespan for investors to know, "hey I've got 50 years of capital free investment into my building and I can get a X amount of return before I will need to look at reinvesting in structural repairs." I would say the lifespan (again speculative) has more to do with documentation and planning from an investment perspective than from an engineering and how the building will hold up perspective.
Only rarely should a building fail or need major repairs before its listed lifespan, but after 1.5 lifespans repairs become much more acceptable. Even shoddy Soviet concrete lasts 50 to 100 years in most cases, and well-built, well-maintained 1st-world concrete should last considerably longer.
Brick homes from what I can read have a lifespan of 100-150 years but the US has a tone of examples where they are much older than that with the oldest in the US being built in 1665 (Bacon Castle in Virginia). If brick is on a solid foundation that goes well below the frost line, and if the mortar is kept in good shape, there is no reason brick should fail short of an earthquake.
Yeah in a nutshell, I think that would be a fair assessment of Building worth and ROI, some other factors are: is my building the best size for my lot or can I build bigger to maximize my usage? Is it historical to where ROI might be excluded and your forced to maintain? Can I convert the structure to something more cost effective?
We have also never been able to build these big buildings in humanity before so we might see something completely different in 50-100 years too. I think, "man, imagine if a skyscraper in New York City needed to be demolished right on times square because end of life is up, how would you even begin to accomplish that safely?" Would you still need to keep a building up regardless of ROI because the task is too monumental and not feasible ?
Controlled demolition is pretty impressive, but some buildings are so tall/narrow that I also wonder if disassembly will be needed.
Usually, I am less worried about the condition of mechanical and electrical components, as these are typically maintained in working condition. I tend to worry more about buildings around 50 years old (and older) and specifically about passive assets such as roofs, drain and domestic plumbing, fire suppression water pipe and valves, and as things get really old, then we think about wiring (buildings built that long ago never expected to have the electrical loads that technology brought us over the last few decades).
In Hawaii for example, the galvanized steel on the rooftop ductwork rusted out after only 5 years due to the salty air.
When you start needing foundational repairs to an existing building, it might be time to look at building a new building. But you may not be able to because of restrictions on historical designations. They bought it because they got tax breaks but now they're stuck with it.
You shouldn't have any structural or foundation damage even after 100 years as long as the rebar isn't exposed. After 50 years all the mechanical systems will probably be at the end of their lifecycle and maintenance will get more expensive.
But the Empire State building is still around. Steel buildings are encased for fireproofing and to prevent rust and concrete lasts a long time.
Lifespan before gutting a building: depends on materials, location- tornados, earthquakes, land movement. I remember one property had a water table underneath it so they built giant ball bearing rollers for movement. You try to renovate to minimize the need to tear it down but sometimes you have to decide if keeping it for the historical value is worth it because sometimes it becomes cheaper just to knock it down.
https://en.wikipedia.org/wiki/Seismic_base_isolation
Plumbing lifespan: Many variables. What type of pipe. Depends on whats going through it. Depends on water quality, whats going down it, chemicals, are there restaurants, where in the building, where geographically, is it cast iron or plastic, etc, etc. In Florida cast iron may only last 25 years because of snow birds, that causes it to expand and contract and flake off and solidify and hot and cold weather can do that too and dumping hot water down it.
For sprinkler heads:
Steel, not cast iron because you can screw it together and the water pressure. Whenever they do major construction they need to drain the system incase someone breaks a head.
They use foam now instead of halon because it's toxic. Server rooms have that. Sprinklers weren't required before the 1970's in the US.
Some houses that are new and super close together require it and duplex and up require it
Life is 50 years then either replace or retrograde.
Black pipe is usually used for gas. Galvanized stainless steel for water has been around for a very long time and is still used today. That lasts maybe 50 years. PVC has different grades, so do copper pipes. Steel and metal before the 1970's was mainly sourced from the US and it had a higher mineral content so it would last longer than the stuff from overseas. The pipe's wall thickness also shrank in some cases, to save money. One old property still had some clay pipes. Companies have developed liners for pipes so that they don't necessarily have to remove everything.
In Canada sprinkler every single fire sprinkler head has to be replaced every 25 years. And every 50 years in the US.
It depends on the age and condition of the building, how many times it's been renovated, what upgrades you've done, how well its maintained, how much capital you've reinvested back into it, level of amenities and market type, depends on the quality, consistency and skill of the maintenance workers and their PM's, insulation, age and efficiency of mechanical equipment such as elevators, HVAC etc. all those equations but generally older buildings have a higher operating cost mainly because the older properties have more maintenance like for example your $200,000 boiler breaks that costs a lot to replace it, you're 25 year old roof needs to be replaced and your elevators are well beyond their service life followed by the exterior and then the interior then the old equipment. Sometimes you spend more keeping an old piece of machinery running than you do buying a new one.You get to the point where you start replacing parts instead of the actual equipment. As a building ages, mechanical parts can become discontinued (they don't make them anymore). You need to renovate. And if you don't renovate, you need to modify. Japanese pipes use a different measurement system than American pipes. So, to add an American pipe onto a Japanese one you need special fittings. So, you modify the old system with a new one since they don't make obsolete parts anymore. If the part isn't available, it's very expensive so you may as well renovate and upgrade to a more efficient system.
As for forecasting the engineering budget, my understanding is the monetary rate increases in maintaining a building: all companies have analysts that have different formulas. It's very heavily tied to inflation and the economy. Big companies like say Hilton or Hyatt can take comprehensive formulas and small companies have individual formulas. Big companies will look at their contractors, say Otis has elevator contracts with 200 Hyatt properties and then another company does another. They will look at those contracts and properties that year and figure out how much the increase will be for growth, parts, etc.
For capex, Hyatt has a formula. For front of house, it goes off historical data gathered through PM logs. Supposed to gut the rooms down to the cement every ten years and redesign them and put in new doors and even new AC units if ownership can (but the actual FCU likely goes when the building is demolished). Every 5-6 years you're supposed to do a light remodel so that's drapes, wallpaper, carpet, etc. So, at minimum you should be doing that. Because carpet after ten years is awful from all the tread. Back of house goes off manufacture recommendations. So, gaskets, bearings, motors its of many windings or when the bearing needs to be replaced. Eventually it all needs to be replaced. Piping that is exposed to a lot of acidic substances like chlorine (pools), fruit juice from a bar getting dumped down the drain all the time will corrode a lot faster. CPCV is a much stronger, chemically resistant plastic pipe compared to PVC.
But generally, the cost of maintenance goes up with the rate of inflation. Also, as the building gets older there's more wear and tear, so more maintenance is required and parts become less available, so repairs become more labor intensive. Elevators are probably the most expensive item in a high-rise. It's well over a million dollars to replace them. Elevator maintenance cost goes up by about 5% a year. Elevator mechanics charge very high amounts per hour. Also Fire Life Safety Systems also have extremely costly maintenance. Otherwise, everyone else (maintenance cost increases) just tracks inflation and the economy. With renovations regarding mechanical rooms, there is a life cycle expectancy from the manufacturer for every piece of equipment. Ownership can pushback sometimes, if you can replace parts then you don't need to order new equipment. A lot of times it can be put off until a major overhaul is needed like every 25 years or so.
The cost of maintenance & repair and the price of rooms is always moving further apart in opposite directions. So, ownership must renovate lightly every 3-5 years and major every 7-10. Investment in the property is so important and it's why the now century old Fairmont Hotel in Seattle can charge $200 more per room after their major renovation (down to the studs). The value of the room/property needs to exceed the price.
Thats also why PM preventative maintenance is so important. The lobby carpet gets replaced the most often because it has the most tread. So, if people associate the old carpet in the lobby with the rooms, even though its separate, its psychological and can bring down the perceived value of the hotel.
Expectation to grow profits, but the amount is highly variable. It's based on the NOI (debt servicing), the fixed costs of ownership like insurance, debt, labor, etc. People and debt are the two biggest expenses. A myriad of factors are at play… including the structure of how much return on investment and flow owners require from operations.
