This Old Green Building
Posted by Glenn on June 30, 2006 - 12:02pm in The Oil Drum: Local
228 East Third Street - A Green Building under Contruction by Chris Benedict
While transportation is the biggest consumer of oil in the US, heating/cooling, lighting and running the appliances in our homes is an enormous user of energy resources. And much of it is crucial to our survival. As we approach the types of infrastructure improvements we need to make in this country, the buildings in which we live are prehaps the most important.
While there are a number of green buildings that have been completed in NYC and across the country over the last few years, there have only been a few major retrofits of old buildings that I am aware of. Most neighborhoods and cities don't even have any real Green Buildings. But just because it's old and wasn't built with LEED in mind, it doesn't mean it can't be improved. Considering the housing stock of NYC turns over pretty slowly, even if all new buildings are built to LEED gold or platinum standards, it will take over 100 years to make the city's housing stock environmentally friendly on a grand scale. In the short term it is much better to simply retrofit an existing building to be as green as possible for the rest of it's useful life rather than tear it down prematurely and built it up from scratch.
How could we differentiate for prospective home buyers or renters which buildings they should choose because it their green features? How could we stimulate recalcitrant real estate companies to invest in retrofiting older buildings to consume less energy and water? What features would be appropriate for a real estate agent or a management company to promote as green?
- Energy Star Appliances which use a fraction of the electricity that other appliances do
- Fluorescent Lighting in Common Areas...Passive Solar lighting...both save tremendously on lighting costs.
- Roof Garden with Trees or other vegetation to
- Bicycle Parking to encourage an environmentally clean form of transportation
- Conducted an Energy Audit and implemented all the recommendations to improve insulation and heating/lighting efficiency.
- Buys Con Edison Green Power...or maybe offsets carbon footprint with carbon credits or something like that
- Low flow toilets, showers and perhaps a solar hot water heater
Eventually it would be great to have some kind of grading or point system to help differentiate buildings on something other than sq.ft., price and location. This could be a way to motivate some building owners to make improvements and renters to ask questions about how green the building is.
So here is my challenge to TOD readers: How would you rate buildings in cities on their green attributes? What would be the best way to promote this idea and get some national organization (or a series of local ones?) to take on the challenge of creating a system to rate buildings on their energy efficiency and environmentally friendly attributes.
For the time being, we may run a contest over at the Upper Green Side to see which is the greenest building in our neighborhood.
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I live in a 2 story, 2000 square foot home in central Florida and have been able to keep my electric bills below $150 even in July. Some things that I did that any DIYer can do are:
Start in the attic. Seal all holes that enter the attic with foam or caulk. Vents, electrical holes, fireplace and pipe chases, everything. Seal all duct seams with duct mastic, not duct tape. Many leaks can't be detected as they are too small. Just seal all the seams in all the ducts. After all that work is done you can upgrade your attic insulation and it will do some good.
Inside your house you want to seal all the holes in the wall envelope. That would be light fixture penetrations, vent fans, plumbing pipes, baseboard to foundation, electrical outlets, AC vents. Use mastic, foam and caulk to keep any air from leaving the conditioned space.
Use foam weatherstriping to seal doors, attic acceses. Seal your firplace chimmney when not in use.
These upgrades are quite inexpensive, mainly requiring labor, but provide the biggest improvements. The goal is to keep any heat or AC that you pay for inside your home for as long as possible.
And then use a heat exchanger or heat pump to not loose energy thru the ventilation.
The nice thing with using a heat pump is that you can use separated ductwork for air entering and leaving or only one set of ductwork for air leaving with an air to water heat pump and radiators / cooling baffels.
Also, during the AIA convention in LA, one of our architects went on a tour of a prominent LEED-certified building, but was annoyed because the tour guide kept pointing at things and saying how many LEED credits they were worth, instead of explaining how they made the building work better.
A lot of architects are sold on LEED, green building, etc. but in reality the building maintenance types have a lot more sway in renovation projects. I like Roof Gardens, but my institutional clients have been paranoid about roof leaks, roof warranties, etc.
I would want secure bike storage within the building, perhaps lockers sized for full-size or folding bikes, but the building guy just sees muddy tires tracking in more dirt, and handlebars whacking his door jambs and scraping his walls.
Do the buildings actually achieve what they're supposed to do, not just post-commissioning but a year or two after? Does it matter? Does a building need to maintain its LEED certification?
I have a passing familiarity with one LEED building with on-site wastewater treatment and recycling of grey water. The building couldn't control bacteria in the cooling tower using 100% grey water for make-up. They had to go to 50% domestic water make-up. Does it matter?
I also advocate for retrofitting, despite the clear advantages of buildings that can be designed for energy efficiency from the ground up. I'm thinking about Maine's having some of the oldest housing stock in the country, and of course the economic realities of most Mainers when it comes to adapting to new energy realities. There are some great designs for very technically simple Hot Air and Hot Water systems, and I hope to create both for my own family, and for working people in general some designs (and maybe products) that would make it as simple and cheap as possible to suck in a bit of the heat raining down on us, and keep it inside..
re: NYC
I would be interested in seeing a comparison of Heat energy required for the average NYC 6-floor walkup, PER Person, as opposed to single-family dwellings, which don't share any heat between families. I think there are some huge advantages in the Cities that should be measured in terms of peoples' energy footprints. (Plus Walkability, Transit, etc)
Your best investment might be insulating and sealing rather than any kind of energy production or capture. Is your building brick or frame? What you can do depends on what you've got; if you can blow expanding foam into the walls of a balloon-framed structure, it's going to be a lot simpler than trying to slap something on the inside of brick walls.
Seals and better insulation started on day one, along with window replacements, insulated window 'quilts' that cover the glass at night, redirecting dryer exhaust INTO the basement in the wintertime, and other mods.
I don't think it's one OR the other.. I see it as akin to money.. you have to make what you can, and also limit your expenses, save. I hear the advice of economizing first, then adding generative capacity, but I am always looking at both sides of the equation. I also hear how people have added a little generation, and it has further inspired them to take measures necessary to see that none of it is ever thrown away again. I think it's actually sometimes the reverse of the common wisdom of waiting till later to get some generation/heating started.. just like I decided the adage about NYC being 'a nice place to visit, but you wouldn't want to live there' was also backwards to my experience.. I love living there, when I have a place to get home to and shut the door and chill, but I'm always more jumpy and unsettled when I'm visiting, due for the bus home, time is short and no chance to do all the things you want to do..
As far as the bike ideas above, by the way..
I've built an outdoor Bike-Garage onto our house, so the tenants and we can access our bikes easily, without dragging them up stairs, scratching walls and doors, and fighting with them for living space. Can't wait to expand it, and get a proper Trailer for my bike to do some errands and jobs from.
Why go anywhere without a bike? My folder fits into a large suitcase and so I can check it onto a plane with no fee and no fuss. Many busses in the Twin Cities have accommodations for bikes, and I daresay other places do this on certain routes.
Lots of people take their bikes by air. HOWEVER, that is expensive and inconvenient, because you have to partially disassemble the bike (usually) and fit it into a special and expensive carton, which is then probably thrown away and burned at point of destination. BTW, when I travel I do not take my laptop or other nonessentials. I usually take with me a few liters of good tap water (in carry-on luggage) and also a few pounds of food. This is a good allocation for when one is stranded in an airport overnight.
Once again, I question: Why go anywhere without a bike?
I've always thought that obese people should pay more on planes.
Thermal storage is great for any time of year, but especially when the wood stove is roaring away and tending to overheat things.
Old buildings can be done over green. Look at the Friends Committee on National Legislation (fcnl.org). bldg right across the street from the senate office building in DC. They did a great job, but spent some big gobs of money, some of it mine, to do it. Now I am hoping those senators will take a look when they are not dodging all those terrorists behind the lamp posts.
Situations differ. Why keep an unoccupied room comfortable ? Sure, enough to not freeze the pipes, but beyond that ?
I come in, turn on my window a/c (SEER 11 heat pump), strip quickly, perhaps take a quick "unheated" water shower (my NG is off and will stay off till October) and it is acceptable within a few minutes close to the a/c. I keep the door closed to the front room so as not cool it.
More thermal mass just slows the process and keeps me uncomfortable longer. And the temperature delta between inside & out shrinks when I am away with low internal thermal mass.
That's only true of environs so far south (and with very shallow water mains), though. And if you were cooling by e.g. passively radiating heat to the sky at night, thermal mass would be the only way you could enjoy the benefits during the day.
But there are places in the US where the daily temp goes up and down like a yo-yo, and thermal mass can be used to great effect if you have the equivalent of a Maxwell demon working the in and out valves. fortunately, yu can buy maxwell demons at radio shack these days.
Not much overnight cooling !
We had one of the county commissioners over for dinner the other night and I probed him about his vision to cut co2 emissions. His concept is to set goals for each energy sector. For housing, an energy budget would be established for, say, a 2400 square foot house. Anyone building a new house would have to not only meet code but stay within that energy budget even if their house was considerably bigger. It is also possible that a maximum house size may be established regardless of what energy conservation/solar,etc. measures were used to mitigate energy use.
In addition, at point of sale, sellers would have to upgrade their house to meet certain standards for insulation, lighting, etc. This would vary somewhat depending upon feasibility.
Part of the energy budget will be the embodied energy of the house, so this will tend to further discourage larger homes. Like elsewhere, it seems that homes just keep getting bigger and bigger, despite talk of peak oil and global warming.
Because of lack of national leadership, cities and counties throughout the nation are exploring way they can meet the Kyoto protocol. This isn't sufficient, but it will get us started in coming up with models that will actually make a difference.
The key here is that you need to know where you are compared to, say 1990, and then set real goals to bring you below emissions for 1990 or some other point of reference. Once you have the goals, you need to set specific standards and strategies to get you there.
The point of sale strategy may be the most controversial part of this "plan" but it must be done. Just dealing with new housing won't get the job done in any kind of useful time frame.
We need to go further, of course, and deal somehow with existing homes that are not being sold. That will probably be the toughest nut because I don't think we have the money on the county level to do this through incentives. There are some tax incentives at the federal level, but I'm not aware to what extent this is being taken advantage of. I suspect that inertia is preventing most people from taking action. Even with some incentives, most people may feel they don't have the discretionary income to do anything. Utilities probably need to be required to provide the upfront loancosts for this sort of thing. The loan costs could be debited against the utility bill. For many investment, the monthly savings would offset the loan costs.
It would seem to me that the buyer should take on that responsibility and roll that into their cost of buying a place. It's a definite thing that the buyer has the money (because otherwise they couldn't buy anything) but the seller may be strapped for cash and be incapable of making the necessary upgrades to sell in that case. It can be a haggling point for the buyer if they need to fix things to bring it to code, which can ensure them the money to do it. Whereas the selled might be strapped with a building, wishing to sell it, but be unable to do so.
http://www.passiv.de/
passivhaus!
An average EU building uses 14 liter oil/m2/year for heating.
The German Passive house concept (Passivhaus)uses max 1.5 liter oil energy per m2 per year for heating.
At present some 6000 have been built in Germany-and a further 1500-2000 in Austria, Switzerland- and a few other countries. Passive houses has been built from Norway to Italy. Schools, highschools, family houses, sport arenas, apartment buildings etc.have been built with the technology.
Applied on old building blocks in Germany the energy use can be brought down to 2.5- 4 liter/m2/year- roughly one gallon of fuel oil per 10 ft2/year for heating.!
The european cverage climate is similar- or a litte colder than the average US climate- so it should work well over there also :-)
Passive houses are not rocket science- but well known principles in building-coupled with good workmanship. From the middle nineties the principles has been refined. Houses must be airtight- ventilation provided by mechanical ventilation and heat recovery. Windows three layers of glass- insulated frames, finally the insulation layer must be at least 1 foot thick in walls and floor- and 1½ feet the attic. This is a lot- but still not more than the average used in new regularly built buildings in the north og Sweden and Finland.
Passive houses can be found in the hundreds on the internet - open google and write passivhaus.
The fine thing is that a large part of the houses are certified- and maybe 500 houses- incl. energy consumption data for several years can be found on the net.Documented !
A passive house typically cost 7-15% mnore than a regular European house- but the price difference is less than the cost for renovating the citchen.
Most passive houses use renewable energy like solar heat- PV - but usually the heat for the buildings come from heat pumps.
More info on the subject- in english- and German can be found at the WWW. passiv.de mentioned bu Greko above.
Once a home is imsulated to a 1.5 liter standard you really don't have to worry much about heat pumps or passive solar or much anything else. You are living in a cave. Complex or large heating plant is not required. If you cook a lot (at all) or have family activity that alone should keep the house quite warm. Instead give thought to how you will prevent solar gain during the summer months and you can have a cave that stays cool with no further effort.
If seamless spray foam is used for insulation there is no need for 12" studs and all the custom work that requires. 2 or 3 inches of seamless urethane will outperform 12" of fibreglass. Even 12" studs function as a sort of cold bridge. Spray applied insulation saves an enormous amount of time and building material.
I agree totally.Please note that is the average of all EU buildings- for heating only and include all buildings new and old ( from 0 BC to 2006 BC in artic climate and subtropic -living space for approx 450 million people.
On top of this add energy for hot water and electricity and you will end up with a average total energy- end user consumption of some 22-28 liters/m2/y
The 14 liter/m2/y can typically be broken down into approx 5.5 l/m2/y liter for infiltration- ( draft and leak and ventilation) - and the rest to heat loss through the building sleeve.
So renovation and newbuild have to adress both. Plug the gabs but avoid condensation in the construction. airtight vapor barriers - taped and glued airtight to constructeion and placed correctly. In temperate climate zones is vital to get an indoor surface temoperature above some 14 oC in order to avoid condensation and mold. This can only be achieved with an U- value below ca. 0.10- 0.15. W/m2/K (forgive me the units).This can be achieved with all known insulation materials.
For example the new (2006) Danish building regulations are the thoughest in the world today and call for new buildings to use below 5.5 liter/m2 floor area/year for heating.
This means Roof and floor U-value W/m2/K below 0.15 and walls below 0.2 This corresponds to approx 10 inches insulation in walls and floor and 14 inches in the attic for a typical European lambda 35 mW/m K material. Other materials correspondingly. The
A final note on poor performance :-).
Denmark is number three country in the world on energy efficiency- far ahead on other EU countries, measured on GDP/energy use just behind Japan and switzerland. This is the result of constant government measures taken over 35 years- plus high energy prices.
And Denmark is a net energy exporter- the only remaining in the EU. And on windy days Denmark has been close to 100% self supplied with wind energy electricity. Need I mention that the US uses more than the double energy to provide 1000 $ of goods compared to Denmark ? :-)
Many utility companies, either free or for a very small fee will send somebody to check over your house for heating/cooling losses and give specific recommendations along with rough estimates of implementation costs.
My house was begun more than 100 years ago. For 23 years before I owned it it was owned by an engineer who every year made incremental improvements. It is a truly remarkable dwelling, both in Minnesota winters and also during the occasional hot (i.e. over 80 degrees) and humid summer day.
One improvement I would have liked done is clestery windows. Putting windows high enough in the room to insure privacy while letting in daylight would save even more electricity.
Usually it will work. If you are familiar with the construction of your house and your contractor is familiar with the type of house you have and is a thoughtful and responsible person your chances are much better.
Any type of insulation, even badly done weak insulation will change the way moisture travels through and out of your house. Moisture can cause havoc in an older house.
None of this should discourage you. You should be very careful in choosing and working with your contractor.
Checking the responses here in the a.m.
You're right about the possibility of blown insulation settling and shifting. Improvements in materials supposedly have limited this since the days when I was hands-on, but basically, yes, performance with blown-in is variable and somewhat unpredictable.
Hate to discourage someone because I know too much.
It's a big job, insulation is meaningless unless it's complete, so you will have workmen and mess in every corner of your house, then you get to repaint and it's all expensive.
A big question for me would be how good the existing plaster is. If you have thick solid uncracked church plaster you want to keep that and blown-in is probably your only option. If you have plaster that's on its' way out it makes sense to at least consider and compare removing walls and doing a higher performance insulation.
I can tell you that the miserable job of removing lath and plaster is far worse when piles of cellulose come falling down and when it's chopped fibreglass even Mexicans will walk off the job.
And one more time, get a contractor you really want in your house. This is not a job for the lowest bidder or the fastest talker. The work-product is hidden behind walls. You don't know what they've done when you write the check.
However, were I forced to install a new high efficiency furnace, I would simply pull the furnace out and not replace it because the economics wouldn't pan out. Our tenants mostly heat with wood anyway but like the furnace to take the chill off the air some mornings when they don't want to build a fire. In other words, the only heat source would be the current wood heater.
I realize this may be a special case but it would not be at all unusual in my area.
Most of my lighting fixtures have flourscent in them and all the utility ones are tube fixtures. I even have an electric lawn mower and electric tiller. The one non-conventional thing I did was to install a tankless water heater which I love. I never run out of hot water when I use it but I don't pay to keep water hot if I don't use any for 2-3 days.
A couple of friends built a similar house (same builder) but chose to use a conventional water heater and NG furnace instead. Their electric bill is as much as mine (more in summer) and they also have a NG bill.
This is the land of 'cheap electricity' - TVA, which has just announced the intention of REDUCING rates from 3.5% to 5% next year.
Winter heating is a minor issue, half the winters we never get colder than 0C (32 F) and pleasant 20 to 23 C days happen all winter long. Humidity is THE problem, and controlling air inflitration is key to controlling that during the summer. Air source heat pumps are an efficient source of heat and cooling. Just putting the water heater in the attic and setting the temperature low is economic. (perhaps get an electric water heater and turn it off 7 months of the year ?)
Thicker insulation > thicker walls and that is bad for shotgun houses (long & thin is typical here). Colling is very efficient thrmodynamically. 1 BTU of electrical energy will create 4.5 BTUs of cooling with good equipment (I am not a fan of central cooling stations, less efficient IMO).
I am leaning towards historic looking new construction, because I will have greater control. All older homes are elevated (or have storage on the ground floor) so I can elevate it a bit more than required. Steel stud construction (reduce termite issues) with 3/4" 17 mm plywood on outside (now required for wind resistance) and concrete "lap board on top of that). Perhaps thinner plywood with grooves on the inside for greater strength and plaster on top of that.
Wood floors are best IF I can afford them. High ceilings (at least 12'/3.6 m) with transom windows & ceiling fans and a whole house fan.
Solar is an issue. IF I can hide them and not disfigure the neighborhood, I will probably do solar water heating even though I doubt the economics of it.
I plan to wait till housing construction slows in the US and building materials & labor decline (I will do my own electrical & plumbing work). I doubt that I will shrink the house enough to allow for a garden, but who knows ?
PV prices may decline enough to add on when I do build (2008/9 ?) but I will make provision for them if I can without damaging the neghborhood.
I will buy within walking distance of an existing or planned streetcar line.
I would seriously consider structural insulated panels (SIP). Houses using SIP construction are usually so tight that it is necessary to us an air-to-air heat exchanger to get fresh air into the structure. They cost about 15+% more then a stick-built house. There is lots of info on the Internet.
Todd
On solar water heating...I hate the big collectors and they would have looked lousy on my house. I designed semi-concentrating collectors that are only 8" high and blend into the roof. They have worked well for years as a pre-heater system. I use 2-32 foot sections and I get a 50 degree rise in a 30 gallon tank which feeds our main water heater. In the summer the water temperature is 130-150 degrees. I don't use them in the winter because I have a heat exchanger in my wood stove.
You could also consider evacuated tube collectors but you don't seem them much in the states.
Its the other way around, long and thin is bad for insulation efficience regardless of thickness since the area/volume ratio is bad. Besides, what stops you from making the house slightly wider to get room for more insulation?
Btw it seems to be a wonderfull shape for modular serius production after taking a look on wikipedia.
> Colling is very efficient thrmodynamically. 1 BTU of electrical energy will create 4.5 BTUs of cooling with good equipment (I am not a fan of central cooling stations, less efficient IMO).
Still cost money to run, good insulation cost nothing.
How do building elements with a concrete - foamed plastic - concrete sandwich handle immersion in water? They could be perfect with a thick layer of the right plastic, immensely strong, well insulated, and a large thermal mass on the inside.
One alternative is a double shotgun, but that requires two lots, more money, etc. and is often used for two homes.
Width is at a premium with 12 feet, 3.5m or so. Consuming more than 1 foot/30 cm for walls is a loss. But perhaps 25 cm per wall AT MOST.
I would have no interest in modular construction. Good quality construction can still be found in New Orleans. A contractor next door is renovating an old mansion/apartment house that he bought 12 years ago (and lives in) for condos. I have looked at the quality of work and it is excellent.
In addition, by doing electrical & plumbing myself, I can save signficant $.
These are historic areas and the new should blend in with the old.
Almost all shotguns are elevated. The idea is to be elevated enough. Thus weight has some impact on the choice of building materials. Too much weight will cause the piers to shift on our soft soil.
I looked at the sandwich construction, I am allergic to OSB (orientated strand board) and I wonder about the costs of plywood sandwinded with extruded polyurethane. And the placement of utilities in the wall.
Given the large number of fires recently, I prefer more fireproof materials.
And I would rather spend my money on local craftsman than a distant factory. We need to keep our money here, at home.
But I will consider it, perhaps for interior partitions.
If the house is elevated and you can't get the cooling that us here in Chicago get from our basements you want to insulate the floor too. The urethane that insulates SIP panels can be sprayed on site. Spray application makes it seamless. I've no idea who might do this in NOLA but the equipment is far simpler/cheaper than when I did the work and it should not be too hard to find. No way could you need more than 2" walls and floor, 3" attic or roof.
If you are concerned about fire there's this stuff called incaluscent paint. It puts out fires even after they've started. Expensive because it goes on as a thick coating. There's also simple latex paint with sand filler. weighs 222bs./gallon, slows fire spread.
Current urethane formulations are done with outgassing in 24 hours. Ameerican Lung Association has spray urethane as sound insulation at their nat'l office. Oriented strand board does have allergenic components, not all SIPs use OSB.
There are two approaches to underfloor insulation, One is insulate the perimeter (rarely done) and the other is underfloor. Stereotypical is fiberglass insulation suspended by chickenwire stapled to the floor joists. Soft sprayed on insulation will be damaged by cats, workmen et al over time.
It sounds like steel stud walls (6" or 8") with fiberglass insulation, covered with marine plywood (first 4") and outdoor plywood above that, and then covered with "HardiBoard" would be cheaper and better. SIP perhaps for interior walls and ceiling ??
2" thick wood floors give R-2 without treatment.
Interior finish might be grooved thin plywood with plaster (preferred). Or just 5/8" drywall if that is too much $.
However, I am just speculating ATM. Fun though !
I own part of a 1930 "Craftsman" bungalow (~1,100 sq ft) on a great location. I rewired it and installed central air conditioning plus other repairs. I have lived in houses from 1790 to 1924 here in New Orleans. I know and appreciate quality construction. I want a multi-century house.
The most common way to build small houses in Sweden is pouring a concrete slab on top of a thick layer of insulation and then either place build a wooden frame house or stack wide-truck-cargo sized house slices of wooden frame constructioning from a house factory. A small shotgun house is more or less a single such series produced house slice. The production of such house slices is comparable to small car production line.
This makes for houses made out of rectangular shapes with simple roofs wich follows our building traditions nicely. Exept for the most southern Danish provinces most of Sweden have used thick timber walls made somewhat air tight with moss wich makes it natural to build square shapes. There were allways a fireplace in the house wich also heated the narrow open space between the floor and the ground. When modern saw mills were built they were complemented with tounge and groove planks and people started to experiment with all kinds of insulation with plane chips (?) being one of the most popular.
Frame constructioning soon took ower almost the whole small house market while brick and concrete with steel reinforcement replaced stone in larger houses. Wooden houses were prohibited to be higher then two stores after some town fiers. That rule lingered to untill about 10 years ago.
The traditional nearly uninsulated floor with constant heat from a fireplace with a heavy heat accumulating shimney keeping it dry made for problems when the fireplace were replaced with central heating and electrical heating and the floor were insulated. The narrow open space collected damp and mold. This kind of building have been discontinued by all large industrialized house builders exept one who has a silly solution where the raw ground is covered with plastic and an electrical dehumifier is kept running.
There is a debate about where to insulate the floors. With some or most of the insulation above the concrete slab it gets easier to control the temperature in the house. But with only some thin flooring on the slab you get a big thermal mass that evens out the day and night variations and if power fails it keeps the house from freezing for a day or so even if it is very cold outside. It is also cheap and efficient to install tubing for low temperature floor heating in the slab and that is very popular. Low temperature is good for heat pump efficiency and utilizes heat accumulators better if you have a wood fired boiler. It is also common to have some of the inslation as a skirt around the perimeter to keep the ground below the house from freezing.
The most common quality problem is to not give the ground slab enough time to dry. The formal remedy is to have rules for measuring the dryness before applying any sealing flooring. The best remedy is to be an active customer and demand a month or so extra time between pouring and sealing up. A significant ammount of house buyers know how to build wich I think help the market stay honest.
Government initiatives about abut this are clumsy. The latest regulation is an obligatory insurance for correcting building errors that covers company work but not your own work. This means that people building their own house have to pay an expensive insurance that they have no use of what so ever. But I guess that is beneficial for building companies and union workes and the building union is one of the strongest and most supportive of our socialist government. The building worker union is the only major organization who have used kind of rasistical arguments against foreign workers.
Large houses for flats or offices are either made out of stacked concrete sandwich modules or cast in place out of concrete with walls and floors out of concrete or floors in concrete and some or all walls with steel poles and light wood or steel frames that are place built. Long span floors are often made out of long pre cast modules with pre stressed reinforcement.
The most intresting development is to finally get from cm to mm precission in the modules and include locking mechanism to realy make building large houses into a fast stacking of series factory made modules. Another nice idea is to skip the traditional crane and outdoor constructioning and start the build by erecting a large framed tent with a bridge crane is if it were a mechanical workshop. This lessens the waste of building material and avoids all risk of getting damages from rainfall.
Other ways of building small houses that are popular are to make them out of the same concrete sandwich elements that large houses are made off or with thick walls laid with smaller sandwiched or foamed concrete building blocks.
Even better would be to stack two double shotguns on top of each other.
Btw, why could you not have a New Orleans factory making quality shotgun modules like candy? Perhaps with wall technology from frozen food containers. Make them pairable, stackable, with movabe inner walls and let the customer choose the siding. As easy as office modules for hire.
You'll have to frame interior walls for plumbing, but the standard design has chases cut for wiring. I've seen one of the factories where they make (and test) this stuff, it's amazing.
Yes, the numbers might be wildly varying depending on whether the owner is frugal or profligate with the temperature setting, whether there were a lot of heat-generating appliances, whether the weather was extreme or mild, and changing site conditions that affect sun and wind exposure. But maybe it could provide a useful estimate of a dwelling's HVAC efficiency in spite of all that.
However, I do think even new homes should be pressure checked as noted above because contractors can, and do, try to cut corners. This is especially true when it comes to doing the work necessary to reduce air infiltration.
I'm interested in CliffDweller's question above: Do the buildings actually achieve what they're supposed to do, not just post-commissioning but over the long term? Models and lab testing can only get you so far, and long-term, real-world results collected on a large scale might be very useful.