For those who missed last evenings PM (15/04): a couple of helping circles have been started up. One of them is the helping circle ‘Pros and cons of recuperated bricks versus steel’. The goal is to work on a list of pros and cons for the PM of coming Sunday (20/04).
I will be taking the lead of this helping circle. I don’t remember if anyone else in the PM yesterday indicated they wanted to join ( @joannes ) (please let me know via this thread), or if others not present in yesterday’s PM want to join…
Because of limited time and other stuff I am working on, I suggest to work on it in the following way:
collect pros and cons from everyone by Friday noon via this ER thread (helping cirlce or not, @reef-exploring : feel free to collaborate on this). I have made a post on ER a while ago, already mentioning several pros and cons of metal vs (new) bricks : Sustainability of different finishings of facades
somebody of the helping circle puts everything together in a document, maybe giving some context as well, so this can be presented in the PM of 20/04, say by Friday 18:00
others of the helping circle review it on Friday before 19:30, or if time allows it, we have a little online meeting with the helping circle to discuss
we post the document to the group by Saturday morning
In the coordination meeting you mentioned that you understood from the presentation that it would be a finishing in aluminum, while in the estimate ‘steel’ is mentioned.
Did i understand it correctly that your concern is that if it is steel, it will heat up when there is strong sun, and maybe dangerous to get burned?
My reasoning is that if they sell it on the market as a product for finishing facades, than surely it won’t imply possible risks of burning, so i am afraid i didn’t fully understand your worry. Could you explain a bit more why it is important to know if it would be aluminium or steel?
Forget I said it. Apparently both steel and aluminium are possible. See https://openai.com/chatgpt/overview/ put in “What’s the difference between steel and aluminium for the facade of a building?”
I guess my question then is why the architects switched from aluminium to steel.
Changing topics, I have one concern about bricks that I would like to get more clarity on. My experience here at home is that during heat waves it is very difficult to cool down the house at night having the windows open, because the bricks give off so much heat in the evening and at night. Given that our site is a bit in the middle of a heat island, this is something I would like to learn more about.
my thought on it (but will check with the architects as well).
You cannot compare the two situations.
the situation i guess you state is: an ‘old’ building where
the whole structure is made out of brick meaning walls of about 30 to 40 cm thick full of brick (maybe with a cavity, ‘spouw’).
there is no insulation of the outside walls
our situation
the brick is purely used as a finishing, meaning i guess 1 layer of bricks (more or less 7 cm)
we have highly insulated buildings with the brick on the outside.
Like you mention, the bricks will accumulate the warmth during the day (and thus keep the house cooler during the day as the warmth goes into the brick, not into the interior of the house). In the evening, when outside temperatures go down, the brick releases its warmth, to the inside of the house and to the air that comes in where you hope it would have a cooling effect.
As here we have a limited thickness of the brick, the accumulated heath will be far less, so they won’t give off warmth for a very long period (depending of course on the outside temperature during the night).
Secondly as the brick is on the outside of the insulation, the insulation will prevent the bricks giving off the warmth to the interior of the house. So for me their might still be a minor effect of the bricks warming up the air on the outside, that comes in because you open your windows.
=> the way i see it: during heath waves, you need to keep the warmth out during the day (keep the windows closed and use the solar protection). In the evening, when the air is cooler and you want to open the windows (i am not convinced that even during heath waves you will need to open the windows), open them on the northern side (the side of the building that didn’t received sun in the afternoon/evening). And if you don’t have windows on that side, open windows on opposite/different sides of the house so you create a ‘courant d’air/draft’ so you continuously get fresh air that is maybe a little bit heated up.
Personally i find this accumulation of warmth in the bricks rather a positive. In the in between seasons, where you might have a bit of sun during the day, it will be nice to sit on your terrace in the early evening because the bricks give off some warmth, while the outside temperature has cooled down. But again, I think this effect will be limited, because of the limited thickness of the bricks
thinking of another big difference between your situation and our cohousing.
The surface of brick is very limited in our cohousing, our facade is mainly windows, so not only the limited thickness of the brick, but also the limited surface of brick reduces greatly the accumulation capacity of the bricks.
Thanks Els, but none of that reassures me.I would really like to hear from an expert.
FWIW, here’s what my friend ChatGPT had to say about it in summary:
Unshaded brick walls on a passive building will radiate stored heat at night, which can delay interior cooling and impact comfort during a heatwave — especially over multiple days. It won’t “break” the passive design, but it can limit its effectiveness during extreme conditions.
I think it is important to say to chatgpt what the thickness is of your brick wall and maybe also if the insulation is on the outside part of your brick wall or on the inside of your brick wall. A passive building can be a thick brick wall (structure) with insulation (which is not our case). Here it’s important that to make the difference between ‘brick as a finishing’ and ‘brick as a structural material’
I also have been thinking about that, and looking at “ilots de chaleur” in cities, bricks is one of the things that come up…
I see the points made by Els, and indeed maybe the low thickness will mitigate that. But I think talking to an expert would help, because I feel that it’s a double edge sword, and I’m not sure it’s that easy to work out… Not sure what kind of expert would have that knowledge though :-/
I would like to help a bit on this so that it’s not just on you guys, but I’m rather thin in time… I could do a search on specific aspect though if you tell me what could be helpful to look at, so that we don’t double down on the work…
A review might be usefull, once i’m finished, i’ll tag you in this thread once I’m finished. If you want/can take up more, just contact me on signal (but I think I can handle it)
@Sarah : finished with a first draf (link in the post above). I am off for a few hours, I will have a look at it again tonight, with the goal to send it out before midnight today.