Hacker News new | past | comments | ask | show | jobs | submit login
Swedish Couple Builds Greenhouse Around Home (returntonow.net)
850 points by rmason 25 days ago | hide | past | web | favorite | 221 comments

This reminds me of an apartment complex I saw last year, also in Sweden (north of Stockholm, in Norrtälje). Hard to see inside, but it's practically tropical, with palm trees and flowering plants, and all doors of resident's apartments let out into the garden.


Those complexes are retirement homes. It's a very cool concept - they build a horseshoe-shaped apartment building and then glass over the central courtyard to create a huge indoor park for the residents. The apartments all face the indoor area, of course, which maintains a temperate/mid-terranean climate all year round. To the people living there it's like being on a permanent vacation in Spain. https://bovieran.se

There's an entire year-round indoor beach with bungalows and a small forest near Berlin: https://www.tropical-islands.de/en/

Better photos e.g. here: https://www.dailymail.co.uk/news/article-2236995/The-worlds-...

I'm sure it needs plenty of energy, but I'd also bet the glass dome plays its role.

Found it online when was again thinking about how to live through the northern winter.

The building sure wasn't designed for that, however, it was supposed to be a hangar for the cargolifter airship. Went bankrupt with a lot of other things around the dotcom 1.0 failure era.

> I'm sure it needs plenty of energy

So much that it has its own power plant, as far as I know.

Environmental issues aside, pretty cool to stand there in swimming trunks when it's -10 outside and there's half a metre of snow against the glass walls though.

I’d not be surprised if they have a power plant. Not because they need a huge amount of electricity, but it’s a bit remote, so it might have been more economical to just build a generator hall than to get grid access and they can use the waste heat from generators to heat the building which substantially improves their energy efficiency.

This is a current trend. Here's another one being built:


Thought this was cool: streetview from a certain angle shows the property before the development.


My wife lived for many years in this "sandwich" of two apartment towers flanking an atrium:



Doesn't it really hot in the summers in Winnipeg? Is just opening the atrium enough to make it bearable during the summers?

Thanks, this looks pretty comfortable: https://www.youtube.com/watch?v=4DJq6uCZw1k

Very nice - too bad its not a food forest, though ..

This house was the subject of a Kirsten Dirksen video in 2015:


I can't recommend Kirsten Dirksen's channel enough to people interested in architecture, energy efficiency, tiny homes, 'green' construction, etc. Literally hundreds of hours of high-quality content - I'm really curious how she is able to find all of these interesting people who are doing such cool things.



Some other favorites:

Baubotanik shapes living tree branches into building facades - https://www.youtube.com/watch?v=IQdcfiLfgUY

Boeing retiree finds meaning inventing micro homes & high speed trikes - https://www.youtube.com/watch?v=IdyR2zzjGWw

Extreme transformer home in Hong Kong: Gary Chang's 24 rooms in 1 - https://www.youtube.com/watch?v=WB2-2j9e4co

Earth-cooled, shipping container underground CA home for 30K - https://www.youtube.com/watch?v=Z0oFJ2jbkDI

Yokohama narrow tiny house "breathes" & attracts local nature - https://www.youtube.com/watch?v=6Mzj63TJYn4

As well as having great content, the format of her videos is also top-notch. It's way too common to see architecture videos where the camera won't linger more than 5 seconds on anything else than some random zoomed-up composition.

In her videos, you can actually appreciate and immerse yourself in the spaces and the various details. The videos are usually between 10 and 20 minutes and she's not afraid to push it further if there's enough content.

Unfortunately the camera is wobbling a lot which gives me an headache. I cannot watch that. :(

Completely agree.

One of my favorite Kirsten Dirksen videos is about Russ Finch using geothermal energy to grow citrus in a greenhouse located near Alliance, NE.


Second that. That was such a great watch!

I want to take two tesla motors, which according to the tesla tear-down, cost $750 each, then take (2) battery packs - place these into the base as a powertrain to a 20’ unit(s) stacked two tall, such that you have a two-story “tiny-home” which can be moved with ease...

Make it draped with solars which can be pushed out as A-frame or other configs.

And all of this can be done for <$100k

This is my goal.

Cool idea. 20' might be hard to transport... I think a lot of overpasses only clear 13ish feet. You might think about designing a mechanism to lower the roof for transportation.

Check out this crazy transforming mobile tiny house https://youtu.be/CnHGKUh-5O4


That was awesome. Thank you for sharing that.

> I'm really curious how she is able to find all of these interesting people who are doing such cool things.

Her popularity in the area probably means that people inform her of relevant things. I believe that's true for a lot of youtubers.

Wonderful, thank you so much.

The whole article is basically a rehashing of the video with tons of screenshots from it.

Ah, I had a feeling I'd seen this before. Fascinating project, thanks for the link to previous video I had seen a while back!

So strange to see that channel recommended here. It's full of unusual and interesting things.

The human waste - grey water & composting system was interesting.

I wonder how they control humidity inside the home and prevent mildew/mould? The air in the greenhouse would be very humid all year round I would have thought?

I think heat exchange air ventilation systems are quite common in Northern Europe. Presumably you could just keep the windows of the inner house closed most of the time, and then have a ventilation coming from outside through the heat exchanger.

Why would it be humid? Heat doesn't cause humidity. Deserts can be hot and dry.

(Edited are to can be for the pedantic people.)

I think standard household activity would generate a lot of humidity. Usually dwellings vent outside, but here the outside is in a larger "inside".

I'm guessing the greenhouse has its own air regulation set up.

In my part of Northern Europe, in the winter the issue is keeping the inside humid enough. During winter when the air temperature is -10c or less there is basically no water in the air.

We have a MHRV system, but it doesn't account for humidity, so will happily replace all the air inside with dry air from outside (I'm trying to automate it with HASS). Our bathroom fan has a humidity sensor, so doesn't run so much in the winter, but even so the humidity often gets down to 25% rh inside.

Yeah, same here. When it's -10 C or less in the winter, relative humidity can drop to 15%. Because we have a standard heat-exchanger HRV. The rotating-filter ones do manage humidity, but they also tend to freeze up if indoor humidity goes too high.

So we end up using an aerosol humidifier in the winter, and AC plus a dehumidifier in the summer.

Soviet Moscow flats are notorious for constant ~15% humidity in winter. Somehow they manage this even when there is a thaw outside and humidity is quite high.

Yes, this is possibly true, depending on the details of their lifestyle.

On the other hand, the article talks about their use of composting toilets, recycling water, etc. So they may well not be engaging in the same high levels of water consumption as typical modern families in developed countries.

So I remain unconvinced that a warmer environment automatically and without exception translates to high humidity and mold. (I will confess to being born and raised in the state of Georgia. So my idea of hot and humid is perhaps more extreme than average.)

Edit: If you've never lived in dramatically different living arrangements, you may not realize how much lifestyle choices impact details like heat and humidity.

While getting divorced, my sons and I spent a year sharing a single bedroom at a relative's home. We eventually found that removing all cardboard from all food products not only dropped the temperature by 5 degrees Fahrenheit, it put a stop to roaches being attracted to our room.

Prior to that discovery, our room was frequently too hot and humid. Afterwards, it was vastly more comfortable.

We were shocked by the difference. We initially wondered if we were imagining things, but the room had a thermometer in the window. It consistently made a 5 degree difference.

I think you've been here long enough to know that a phrase like "automatically and without exception" is likely a poor interpretation of what the parent poster meant with "standard household activity".

I was born and raised in Florida. In Miami I lived in a 1950s house designed w/o A/C and with effectively no insulation. In Tallahassee I lived in a 1970s house designed for A/C. But we didn't have money, so we didn't run the A/C unless it was nasty hot.

The differences were remarkable. For the same temperature and humidity, the Miami house was much more comfortable. The vernacular architecture of high ceilings, open crawlspace, and massive amounts of windows meant there was still cooling with any sort of breeze.

With the Tallahassee home, the building was designed to insulate, to keep the A/C power bills low. The windows were small, there wasn't much cross-breeze even with all the windows open.

A/C systems include dehumidifiers, and the building has a vapor barrier to prevent the high outside humidity from coming in.

But w/o the A/C's dehumidifier, standard household activity like breathing, cooking, and showering raise the inside humidity more than the outside, with a slow rate of equilibriation.

We finally kicked on the A/C when, among other things, yes, mold started to form.

Of course 'lifestyle choices impact details like heat and humidity'. So does architecture, as I just pointed out. But btbuildem said 'standard' and 'usually'.

I think you've been here long enough to know that a phrase like "automatically and without exception" is likely a poor interpretation of what the parent poster meant with "standard household activity".

I'm damned if I do, damned if I don't. It doesn't matter how I phrase it, people will have a problem with my real point and will have a problem with me giving first-hand testimony from my life.

So I tried to avoid that. It didn't help.

I slept in a tent for nearly six years. I'm back in housing, but I still don't live conventionally. I'm in a hundred year old building with no AC. But I have no upholstered furniture, no mattress, a minimum of bedding.

When other residents are desperately trying to create a cross breeze to cool off their too hot room in summer, I'm usually fine. With no cardboard and no upholstered furniture, my room is not too hot.

So I tried to use specifics from the article itself, like the composting toilet. Toilets are one of the ways modern families go through a lot of water each and every day.

I know my lifestyle generates less heat and humidity in my home compared to other people in the same building as me. I also know most people act like my first-hand experience doesn't count.

I'm routinely downvoted for making such observations, no matter how I try to phrase it. I'm routinely told I'm making stuff up, that's anecdotal, it doesn't count, I need a study or something.

I've seen men here on the leader board give similar personal anecdotes and get treated like they're brilliant. Tokenadult used to tell stories of opening the shades on his windows when he was a young man living in China to use solar power to heat his room and giggling about management accusing him hiding a forbidden heater.

But my first-hand observations are not similarly respected and oohed and aahed over for their insight. Instead, I'm routinely attacked and dismissed.

After a decade, I'm pretty damn sure it isn't my phrasing. It's my gender and general lack of credibility for reasons wholly unrelated to my intelligence, veracity, etc.

It's open contempt for me as a person. And I'm quite fed up with it and even more fed up with being told it's somehow my fault that I'm subjected to this double standard.

Had no idea who you were, hadn't even considered what gender you may be, and I can say that it is your writing style and phrasing that rubs the wrong way. (IMHO) reading your posts came across as if I was being lectured to/talked down to by someone with feelings of superiority.

I'm a male with a literally randomly-selected username and have stopped posting here because of just the kind of thing you cite. It feels too much like school...it's this project to figure out what to say that people will like; fail to please the mob and out come the vultures. Life's too short and full of more wonderful adventures than that. And the payoff from getting it right just isn't there to justify the downside.

I observed that the statement "I remain unconvinced that a warmer environment automatically and without exception translates to high humidity and mold" - while absolutely a personal observation - was a non-sequitur as no one was making that claim.

Was it a non-sequitur?

I then made a personal observation that architecture was also important, using a similar anecdotal construction that you did. So clearly I don't have a problem with anecdotal evidence. I present a similar anecdotal observation at https://news.ycombinator.com/item?id=14876398#14878461 .

I then ended up with the comment that I don't disagree with your comment, because it's clearly true, just like how other factors are also involved.

If you look through my history you'll see I have a long history of making similar observations for other posters. I see four such on the first page of my comments history.

The greenhouse isn't 100% sealed and the top would regularly open during the warm months to regulate the heat inside. On top of that the regular vents could easily be extended slightly to just reach the outside of the greenhouse.

Plants/watering cause humidity and the glass traps it.

And although I guess they probably could, people aren't generally maintaining desert ecosystems in their greenhouses.

This is not a problem in the winter -- outside air (if brought up to room temperature) is extremely dry. So just a bit of air exchange would dry out any jungle if humidity is not supplemented.

Deserts aren’t necessarily hot, they just have very little water.

They have little precipitation. There's plenty of ice in the Antarctic.

Are you sure about that? A river delta could be completely lush without any precipitation, but I don’t think that’d be a desert.

From the link someone else already provided:

Most polar deserts are covered in ice sheets, ice fields, or ice caps.

(I'm getting a chuckle out of the multiple layers of pedantry here.)

Nile delta is in a desert (4-8" rain/yr), so yes.

But greenhouses are humid. Deserts aren't covered in a dome and the dome blocks water from evaporating like in the deserts.

Not much grows in a dry desert though, to grow stuff you need water. Even if you weren't growing stuff then you'd still have the soil as an access point for moisture and get excess evaporation because of the greenhouse heat.

Depends on the desert. Here are pics of Saguaro National Park:


Desert plants are adapted to low rainfall. That doesn't mean all deserts are just barren rock and sand.

Yes, and when the rain comes they burst forth with vibrant life .. hence the specifiers "dry" & "not much".

I guess if they plan to eat agave and saguaro they'll have less humidity issues?

saguaro national park has really grown on me. It’s a surprisingly and eerily beautiful place.

>Why would it be humid?

The hotter air is, the higher its capacity to hold water vapor.



Which actually drop relative humidity, because water does not magically appear.

Dry cold air gets in during the winter, it expands and the RH goes down, warm humid air escapes, more dry cold air gets in, creating an extremely dry environment. Still you can get mold because of condensation when warm air meets cold rooftop.

Yes, but the absolute humidity is the amount of water in air, and particularly n cold climates, this water load can cause considerable trouble in structures. The correct way to design airflows and location of dew point inside the walls etc can be considerable trouble; ad hoc design tends to lead to mildew problems.

I am a little confused about this fear people have of mold and mildew in their houses. Up until very recently people's houses weren't far off from the outside environment. Generally in the summer the best they did was keep the rain out and provide some shade. Houses weren't uninhabitable mold pits back then, why would they be now?

There is some additional risk with modern homes being much better sealed than old homes which always had some air moving through it. If you don't have a proper HVAC system and use like electric heaters instead of forced air, humidity levels can build up and slowly absorb into materials if you don't have enough airflow, and you likely won't notice, unless maybe the dew point gets high enough that all of a sudden every surface in your house is damp. It is less of a concern in places without high humidity but some swampy areas can be 90% humidity for weeks or months at a time and then all of a sudden you got mold behind your walls because some idiot decided to seal up every seam with plastic or glue or whatever other impermeable material.

Part of this is a misunderstanding of building techniques that block airflow, ive seen numerous houses with all the roof vents plugged up to "save heat", walls with plastic sheeting on the inside wall creating air/moisture traps, or people replacing air-permeable house wrap with solid sheet plastic, foam and glue on every board and seam with a sealed up and moist crawl space underneath, ect. It is fairly easy to get mold in a humid place with a sealed home and no forced air, and nearly impossible to kill it all without tearing out all the drywall in the house. If everything was done right, shouldn't be a problem, but people are far more likely to pay for size and speed over quality materials or careful quality labor.

Here’s an accessible and illustrated page with some additional details around your point https://www.popularmechanics.com/home/interior-projects/how-...

I’ve seen this turn into a problem with big renovation of old residential structures twice. My personal takeaway was make sure your envelope and HVAC are of roughly equivalent quality and era.

Well exactly because of that. If your house has plenty of air circulation (that's what "people's houses weren't far off from the outside environment" means) then things might get damp, but they will also dry out naturally too. Now you get a huge plastic bag and wrap it around a building. It will keep out rain yes, but also trap in moisture internally and the damp parts will get mouldy. Obviously nobody will do something as silly as that, but with modern materials it become much easier to accidentaly approximate the plastic-bag-wrap experience.

There's lots of things we don't understand about the health interactions, but even if you don't suffer ill effects at least you'll risk stigma if you and your clothes smell of mildew.

It's sometimes hard to imagine how hard and unprecitable lives of past generations were. For most of history people's indoor firepits didn't have chimneys, for example, and the health effects were less of a concern than wars, infectious diseases, getting hurt in physical labour, or famine.

Also, most old houses were well ventilated and built of mildew resistant materials (= poor insulation and wood).

Well just as an example, around here concrete cellars were usually not insulated before. They were storage areas.

In the 80s people started insulating them in the wrong way (on the inside), creating a condensation point between the insulation and concrete => mold.

These days we have learned that cellars must be insulated on the outside (by digging up the garden) or somehow make sure humid indoor air dont make contact with concrete behind insulation.

If you basically don't have plastic and insulation then mold is less of a problem, but you also need to spend a ton of energy keeping the house warm...

It is actually easy to ruin a home by trapping moisture using modern materials carelessly. It happened to many centuries old buildings in the twentieth century after being renovated and modernized to save on heating. Traditional techniques allowed more circulation of air that avoided mold.

The walls of a normal modern insulated house are already completely air tight, first layer behind the walls seen from the inside is a plastic sheet to prevent humidity from indoor human activities to get into the insulation. After building a new house they literally try to inflate it like a balloon and measure the pressure to ensure there is no leakage.

Controlling humidity and air freshness is done through vents, usually combined with a heat exchange to not let out all the warm air you just heated up.

Condensation accumulating larger drops might be a bigger issue with glass though, but only if it's already humid on the inside.

I could be wrong but I think mould appears when humidity condenses to water drops. So you need both humidity and a temperature contrast (e.g., hot inside air meets a cold wall).

So as long as the inside and outside of the house has the same temperature, condensation in random spots should not happen?..

Condensation will be on the glass panels, where mould cannot grow.

I suspect noise level might be quite high too, especially with children.

Still a cool house though, I like their water treatment

"In Stockholm, Sweden, where winter lasts 9 months out of the year",

according to what crazy-ass definition?

3.5 months is a common length of winter for Stockholm, according to the Swedish Meteorological and Hydrological Institute.

The (crazy-ass, yes) definition is in the article: the period the house needs heating.

Yeah, I noticed they mentioned needing heating for about that long. But, really, they didn't explicitly call that winter. Nor should they.

No need to be pedantic, it's cold 9 months in a year, and that's the point we are trying to make here.

I disagree. It's not about being pedantic, but losing confidence that the author understands concepts that are highly relevant to the subject.

Kind of insulting to those who have all 4 seasons. Heating must be done in autumn and spring but I understand winter when it is <0 celsius or close to that or maybe one day +5, other -x. Yeah, that's still winter.

Then write that. Saying winter lasts 9 months is nonsense and nonsense in journalism should be pointed out, though not as aggressively perhaps.

Well now that I think about it, I do welcome literary devices when they are so obvious that they only assume primary schooling. Normally they make the text more human, more fun. Also, I can't really see someone getting deeply confused by this; and momentarily confusion is even good to revisit some knowledge from time to time.

No, its far from nonsense, it makes the article more fun and interesting or maybe the author has different definition of winter. They are not writing formal academic paper.

I agree, you must have misunderstood, I define 'nonsense' as something creative and fun to read.

I define "winter" as the time honeybees don't fly. Summer bees don't fly below 13 Celsius, and winter bees don't fly below 8 Celcius. Winter bees are the first ones out of the hive in spring, raising up the summer bees for the big harvest.

For me winter starts below 15 degrees Celsius :) But for example on Tenerife there's only spring and summer. These things are flexible :)

As a South African, her definition did sort of make sense to me in a social context, but I understand that metereologically it would be incorrect.

The amount of months that Johannesburg would require heating I would say is probably 3—4 or 4—5 if you take into account only minimal heating at the edge cases.

You are using SMHI (The Meteorological service) definition of winter which is

> the daily average temperature is at most 0 degrees Celsius at least 5 days in a row

This doesn't work for the international reader, in many countries the temperatures in the winter never goes below zero

A while ago I came across this story of a similar construction in Norway. It's a slightly different approach, with a custom geodesic dome built around a cob house on an Arctic island: https://mymodernmet.com/hjertefolger-arctic-circle-cob-house....

In The Netherlands 'kaswoningen' (Greenhouse Houses) have been build in 2002, 2005 and 2009 in the city of Culemborg. See: http://www.eva-lanxmeer.nl/over/nu/woningbouwprojecten/kaswo... (in Dutch)

This is my favorite one, built by the Hjertefølgers family in the Artic Circle:


The article mentions that a Swedish architect also built one in 1974: http://bengtwarne.malwa.nu/natureH.html

Cool, I've visited this house! It's located just a few kilometers from where I grew up. Small correction to the article though: it's quite feasible to grow tomatoes and cucumber without a greenhouse in summer in Sweden.

> it's quite feasible to grow tomatoes and cucumber without a greenhouse in summer in Sweden.

Conversely, it's quite difficult to grow them in the City of San Francisco, especially the Western half, in the summer.

Some people have success with a special variety called a fog tomato, but in general, the northern California coastal fog zone ain't no place for a tomato growing, only tomato eating.

Depends on which part of Sweden isn’t it?

Quite. It would be difficult in the polar region. It works great in the Stockholm area though!

Doesn’t it. It does depend or it doesn’t depend.

I wonder if this has a negative effect on the amount of fresh air that they get

Fresh air is created by plants and CO2 is taken from the air by plants, a greenhouse has plants so... probably a good amount of oxigen there

Molds are a problem and there is another, for rodents, mosquitos and cockroaches this is a dream made true. Spiders can take mosquitos easily, but the other two will need a plan

> Fresh air is created by plants and CO2 is taken from the air by plants

Plants can be net CO2 consumers, but they burn O2 to CO2 just like you. Tropical forests are net CO2 producers for most of the day, except for a few hours around noon, but that's enough to become net consumers averaged over the day. Occasionally someone fills their room with plants, and then puzzles over having high CO2 levels.

I imagine it's not much different from a regular residential greenhouse, in which case the plan is to throw a sufficient number of cats in there.

Not sure people in glass houses should be throwing cats.

Mine would love that environment I’m sure though.

They are somewhat softer than stones, but yes, cat throwing is rarely called for.

My mother has a decent sized greenhouse. Her cats spend most of the winter in there by choice - they love it.

No reason a ventilation fan can't be installed - that's standard on modern air-conditioned and insulated houses (a "whole-house fan") precisely in order to rotate the air.

Yes, but ventilating the house itself plus the surrounding greenhouse is much more expensive than just ventilating the house itself. Reason being that the volume of air is much larger.

I'm not an expert, but all greenhouses I've personally seen have natural ventilation with vents high up (such as at the peak of the roof) and near the ground.

The greenhouse effect makes the air inside a lot warmer than outside. This reduces its density, and it becomes buoyant and spills out the roof vent.

There may also be fans, but you can get some ventilation for free (energy-wise).

You can see the open vents on the ridge in the first photo.

That might help, but it's not quite the same as a nice summer breeze flowing through your house.

It literally is a summer breeze flowing through your house.

In the summer, the greenhouse opens up.

Then they will lose all the advantages of the green house if they get cold air from outside...

Balanced ventilation (not sure what the English term is) is standard these days and recovers about 90% of the energy (heats air going in using the air going out). I have one at home.

Dont know if they have one set up, but they could. But possibly the sun already warms it enough even in winter that it is not needed even with natural ventilation.

> Balanced ventilation (not sure what the English term is)

Heat exchanger: https://en.wikipedia.org/wiki/Heat_exchanger#HVAC_air_coils

That may be. The word we use is more a property of the ventilation system ... that you blow as much air into the house as out of it, active airflow in both directions. (As opposed to older ventilation where only exhaust has a fan.) This facilitates plugging in a heat exchanger.

To be clear I did not mean HVAC, which requires (some) energy in itself.

At home I do not have HVAC. However, the outbound air passes through a rotating metal structure that sucks up the heat from outbound air and releases it into the colder inbound air. Just using the temperature gradient that is there naturally. Passive energy transfer.

Same principle can be used with hot water (e.g. from showers).

Then one can put HVAC on top of this for active warming.

I wonder how much fresh air they get from all the plants pumping oxygen out?

Plants produce oxygen when they grow, and you would need to grow about 8 pounds a day to supply oxygen for one human. See https://www.gardenmyths.com/houseplants-increase-oxygen-leve...

I wonder if the photosynthesis from all of the plants would make the air feel fresher

I also wonder if the increased humidity increases the chance for mold.

Most greenhouses have ventilation windows, often using a wax piston to automatically open/close windows based on the temperature.

Had never seen a wax piston, that’s a tremendously elegant design.

How does a house get fresh air?

In the Nordics, houses (that aren't very old) don't get new air through windows; the air exchange is through a central ventilation system in and out, and modern houses have a heat exchanger to collect the heat from outgoing air and transfer it to incoming air. (The need to cool down residential houses is extremely rare).

At least in Finland, newish office houses typically don't even have windows that can be opened; this seems to be a surprise to any foreign visitors.

> At least in Finland, newish office houses typically don't even have windows that can be opened.

That's because the costs for heating of the building during winter are way cheaper than a better thermal isolation of windows and a good ventilation system combined.

I think you express it the wrong way round. The windows cannot be opened, because that way they can be made better for thermal isolation, which is obviously a major design criteria in cold climate.

It's more like you got lost in the comparison spiral. Formal interpretation of my phrase: cost of heating with unlocked windows > (permalocked windows + ventilation system).

I live 55°N in Russia so I know that from practice, but we don't lock the windows throughout the summer because the cooling would cost around the same as heating in winter, just one or two opened windows in the night for convection and curtains in the daylight are enough to keep the temperature.

No, you are the one missing the point. Modern building design is based on an (ideally) thermo-proof house, minimal heating and carefully controlled ventilation. In the winter, the warmth of inhabitants plus some minuscule floor heating is enough to keep it warm. In summer, thermal insulation and shading keeps it cool indoor. The goal is to make the indoor temperature passively independent of the outdoor temperature. Nothing to do with cost optimization.

> The goal is to make the indoor temperature passively independent of the outdoor temperature. Nothing to do with cost optimization.

These sentences contradict with each other. The cost is not only payments for service, it's a sum of resources, time and work needed to make and maintain. You can't make a thermal system cool itself passively due to the 2nd law of thermodynamics.

The difference between Helsinki and the place I live is that they don't have temperatures above 30°C while here I have those at least 2 weeks straight each year. Passive ventilation stops in those temperatures because there are no wind outdoors besides the hot columns of air from heated surfaces, HVAC costs are the same as winter's heating while it's PITA to clean them from ice each spring, a window ventilation during the night refreshes the air good enough.

I think you are confusing the "passive" here. It refers to heat insulation and minimizing the need for generating either heat or coolness; the house is not "passive" in the sense that it would just sit there.

So the "passive" houses are not at all passive in terms of technology (to the contrary, they are quite dependent on technical solutions enforcing airflows and exchanging heat up or down, to the point of being vulnerable; the point is just that this is not done through windows because humans intuitively don't do it so well or optimize for the whole building).

Some years ago, there was an electricity outage in the area where my office was. The basement floor had our server room with plenty of blade and rackmount servers, and some 30 kW of UPS capacity - which had been unused for years because electricity outages are extremely rare here. UPS is all very well to keep servers running, but this happened in the summer and the server room cooling system was not behind the UPS like the servers were. Thus, we suddenly have a 30 kW unbalanced heat load to the basement floor... Result was some frantic running up and down. None of the windows could be opened. We could open garage doors in the basement floor, open all the doors to stairways and halls, and run the the top floor which has the usual sauna compartment with doors to a balcony - opening all these, we could create a chimney effect to get airflow through the premises and prevent our servers from melting on the spot while we were shutting them down gracefully in priority order.

Which part can't be done here?

Not sure what you mean, but the reason for sealed windows is that building code mandates all ventilation through heat exchangers for energy efficiency, and having windows open would completely ruin the designed airflow.

Growing up a had a friend that grew up in a supper insulated house (it was blown insulation for walls). They had electric heat. They built a greenhouse on the side of the house that provided a lot of the heat in the winter. Because the trees where leafy it was shaded in the summer and they used fans to move the heat it worked out well.

They sold the house and it was torn down, but it was An interesting structure.

To me, that construction would seem like a hell over the six months that is actually quite warm at these latitudes. I basically already keep my windows open from spring to late autumn without a glass dome like that, and it still gets hot inside during the summer months because the air outside is hot and only cools down during night. Now, add a greenhouse around the house and you'd never get fresh air blowing directly indoors. Yeah, you can seal the house and add air conditioning and heat pumps but hey there goes any natural ventilation, and now you have that carefully controlled technology that needs to be kept running or you'll risk mould should one part of the hvac puzzle go defunct.

The openable panes of the greenhouse are probably way larger, and you can easily open the top panes to create a large updraft throughout the greenhouse.

Greenhouses don't stay unused in the summer, and heating up to unlivable temperatures would also kill the plantations. Therefore "permanent" greenhouses (as opposed to the plastic tarps on struts you build up and take down at appropriate times) can be down-regulated to an extent (to not too high above ambient temperature).

I've thought about building a house in a barn to save on heating/cooling (Texas, it's dadgum hot here). But this is much much cooler (or warmer, if you're in Sweden)!

You might like Matt Risinger's YouTube channel, https://www.youtube.com/user/MattRisinger . He's a builder in the Austin area who does very energy efficient homes. He uses (a variation of?) this thing called a "100-year wall" system, the gist of which is that the entire envelope of the house is sheathed and sealed, basically turning the frame of the house into "furniture," in that it's in a conditioned space. The big insight is that the vapor-barrier-on-the-inside scheme came about in climates that were mostly dry outside, and mostly moister inside, whereas large areas of Texas (and tropical and subtropical areas) are the reverse.

Matt Risinger's show is great. I think it's awesome how he brings high performance low energy footprint home building ideas to audiences that might not otherwise be exposed to them.

A sibling comment suggests that the insulation-on-the-inside approach (for cellars, at least) has been found to be wrong anyway for moisture-on-the-inside.

a pole barn with no walls should be enough?

Very very cool.

How would this fare in the summer months?

I.E. How would this work in the US Midwest where summers are very hot and winters are pretty cold?

How much would something like that cost?

He claimed to have spent 80K euros on it 10 years ago. No idea what prices would be in the States. But I'm guessing that 80K figure is for the glass alone.

It looks great. 80k investment to go from 9 months of heating to 6 months. Expensive project, wonder if solar would have yielded more in the north.

Well I think it's as much about happiness as it is energy efficiency. They get to enjoy the outdoors year round.

Isn't a green house a solar collector in some way? They get their heat from the sun, and their main mechanism is simply trapping it in a closed environment.

I think the parent commenter meant to imply buying $80k of solar panels.

I have a documentary about this house from Swedish national public television if anyone is interested.

Its an interesting project. I wonder how they keep earthworm or other insects out of home.

I would imagine they try to encourage earthworms as well as many types of insect.

But probably not inside the house

I would venture a guess that this kind of construction did not happen in mass historically due to cost and materials? EDIT: (That includes manifacturing cost and ability.)

In Britain I have seen that their glass conservatories are quite popular (and many are much older), but they are typically only one room.

Could it also be that the greenhouse effect was not fully appreciated until later in human history? I would also guess that glass would have been much more expensive in ancient times.

A different house from SVT's (Swedish national public television) series called Husdrömmar (House Dreams):


I have loved this concept ever since I discovered Michael Reynolds Earthship. I wonder if their exterior is glass or polycarbonate?

According to the movie it's security glass, the type that if it breaks, it breaks in thousands of tiny pieces.

That must mean it's tempered at least, which would be safer. And I believe polycarbonate yellows after long-term exposure to UV, but would have more structural integrity. Glass would probably be better in the long run but they better not have any exterior trees with their high-wind-branch-shrapnel in proximity to the glass lol

I wonder how much money it would cost to figure out whether you are allowed to build such a construction in Germany at all.

I've seen a similar construction in Germany so I assume it's allowed.

Any insights on what this would cost to build?

This is a dream of mine. To live a very simple life off the land, powered by the sun, creating art, building things, not needing to be connected 24/7. Take care of some alpacas, maybe create an animal rescue facility or with enough acres, a refuge.

I always thought this would be an interesting experiment to do this over a whole neighbourhood

There was a Stephen King story about that. Turns out it leads to the collapse of law and order and lots of people die.

Most Stephen king novels lead to societal collapse and people turning on each other. It makes for a great read but it doesn't seem that's what people actually do in a disaster. They usually help each other and try to rebuild society.

A great book on the subject is "A Paradise Built in Hell."

Wasn't it also the theme of one of the Simpson's movies? (Probably based off the Stephen King novel?)

The Simpsons Movie (called just that) actually predates the novel.

Do you recall which story that was? Sounds like a fun read.

"Under The Dome" probably


The house would also last longer as it wouldn’t be in contact with rain.

Rainforest houses in Australia (yes.. it’s a thing) are built out of wood and last like realistically only about 15 or 20 years before they’re practically falling apart from rot.

That's a ... really really large greenhouse.

They're about halfway to a workable Mars habitat.

If building two such big greenhouses was enough to live on Mars, we'd already have been there.

Not as far as greenhouses go!

Their Neighborhood Housing Association is much more patient than mine

I was wondering about something similar, but also designed to add suspended floors above existing structures in order to increase housing density without tearing down streets.

Is there is some basic maintenance cost for this house or not... Knowing the fact of saving electricity from heating device, How much it saves?...

How much snow do they get? Seems like it would be serious work to make sure ice and snow didn't pile up or bring down the greenhouse.

Does the warmth of a traditional greenhouse melt snow from the roof?

Greenhouses depend on at least some sunshine to stay warm, as mentioned in the article. If it's snowing, it isn't sunny, and if the snow piles up, then you have trouble. Around here, it's not unusual to get half a metre of snow overnight. The greenhouse these people built is made from glass and it's difficult to see it surviving a proper winter.

Another problem with this is humidity. I wonder how they deal with possible mould and dampness?

It's a 10 year old house so it has survived a few winters already...in Sweden.

I assume by "...in Sweden", you are implying Stockholm gets fierce winters. But it doesn't really. It gets a lot of sun (comparatively) and not much snow. I was wondering about real snowfall accumulation.

Stockholm doesn't get much sun in the winter. Average for the month of December is somewhere around 20 hours. (per the whole month).


We have greenhouses far north of Stockholm too and they work just fine so far. They can be built quite stable and ofcourse they do that where snow is expected.

The have a furnace and no roof, so I would assume worst case they blast the heat and melt some of the snow so it slides off.

Humidity - the greenhouse opens up so they can easily let out excess moisture.

Right, that makes sense. I guess there is some experience required to keep things dry. I am no fan of humidity so for me personally, I think this setup would be a struggle.

I love humidity. This is inspiring all sorts of interesting ideas for me.

I would assume it must simply remain warm enough, while being sloped enough and continuously bleeding enough heat to achieve the next step, to melt a lubricating layer of water from the contact ice and allow it to easily slide off.

I think the slope helps a lot. If you look at a lot of homes in areas that get a lot of snow, they’re sloped so the snow slides off. Glass would probably help this too.

My parents owned a flat roof home briefly and had to shovel it.

The roof isn't flat, so you don't need to melt all the snow. Just the thin layer at the bottom that makes contact with the glass, and the rest should slide off.

Several of our neighbors have rooftop solar panels. The snow tends to slide off easily due to the slippery glass surface.

It can’t be worse than maintaining any other large greenhouse during the winter. You also have the latent heat from the house itself to keep the space warm throughout the night

Don't greenhouses use energy? I thought Dutch high intensity agriculture greenhouses used quite a lot of it.

I can hear the sounds of 100k HOAs screaming in the night thinking about someone doing this in “their” neighborhood.

Wonder about the legality of doing this.. seeing this made me want to do the same although I would hardly know where to begin

Interesting to see how well the fruit and veg grows during the winter periods with less sunlight. Maybe they are smaller?

This might work even on Moon or Mars with transparent solar panels and fertile soil

Probably not, because the lack of a magnetic field and atmosphere means the surface of Mars is much more exposed to harmful radiation and meteorites, respectively.

If you like this, you should check out the work of Amory Lovins. Negawatts!

similar video: https://www.youtube.com/watch?v=lc_clnBY-2I

Both very cool!

Don’t know if it the glass needs to be cleaned regularly

Often it does, but people sometimes use self-cleaning glass that at least Pilkington makes.

And in Amsterdam - of all places, the capital of one the countries most threatened by rising sea levels - the idiots keep gas fired terrace warmers burning at full blast.

Cycling through the city feels like the deck of the Titanic.


We'll build the dikes another few metres taller. Shrug...

You seem to be missing the point.

It’s not just about building higher dikes.

It’s about the ethical soundless of pissing tons of CO2 in the wind just because you can’t be bothered to wear a sweater. (What does that inscription next to Leidseplein say?)

Edit: it’s also not just about higher dikes in NL, the effects of that CO2 goes well beyond the Dutch border. It’s Global Warming after all... global.

The cognitive dissonance of this attitude, compared to the Swedes building greenhouse homes to save on energy, is what makes it feel like we’re swingin’ on the Titanic.

Unless your carbon footprint is that of an Uttar Pradesh subsistence farmer there's no reason to point fingers

No, lets leave true Scotsmen alone.

Ethics are subjective

Not when the consequences of our actions are not.

A psychopath might say the consequences are acceptable or ok so it's still subjective

If you make them taller, you also need to make them wider. The cost of dikes goes up with the square of their height.

No, I agree it's irresponsible to heat outdoor terraces so much during winter. Go sit inside if you want to be warm.

So the Dutch will survive the warming and they already know how to grow boatloads of veggies on the scraps of land. (Afaik the second place in export of vegs isn't just from the flowers.)

they won't need the greenhouse for very long. in a few years it'll be warm enough to grow figs outside without the greenhouse

You're being downvoted, but there are places here in the Netherlands where figs are doing well where they didn't 20 years ago.

The cleaning bill on that would give me PTSD.

That website has far too many chum boxes.

Great but they should avoid burning wood in highly populated area. Because it is generating a lot of small particules, worse than a car.

Not when using a modern burner that circulates the gasses until they are completely burned. If it is one thing we know in Scandinavia, it is burning wood efficiently.

You can burn wood quite efficiently with a gasification burner and filtering device.


I wonder how it does in windstorms, though.

Very cool!

Sure, they reduced the heating bill. But the tradeoff is that they can't throw stones anymore.

rolls eyes... take your upvote and go.

Imagine the flocks of dead birds around their house.

All natural source of animal protein. They've built a catch around the greenhouse.

Yea, I was thinking they shouldn't throw stones...

Well, the Javits Center is still standing

The title should say 2015. This is just a spammy article that took a 2015 youtube video, described it and took some screenshots.

I remember this when I saw it in 2015. The whole project is dumb. It's extremely expensive, they will never break even on the heating costs. It's completely unprotected from hail. The ventilation is horrible. Humidity is high.

Sure, it's creative and fun, but let's not paint it as groundbreaking.

>Any supplemental heat they need, that is not provided by the sun, is provided by a wood-burning stove.

Such green, much modern, wow!

Edit: Hm, others in the thread have pointed out one could use a gasification burner

Registration is open for Startup School 2019. Classes start July 22nd.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact