ᐅ How does insulation in brick construction affect the indoor climate?

We are considering three building options: timber frame, solid wood, or a brick house.

Many timber frame manufacturers, such as Griffner, advertise that their indoor climate is especially good because only wood is used in the walls and they are vapor-permeable, allowing moisture to be released effectively.

I have also heard several times that bricks are very good for indoor climate because they conduct moisture well. But here is the question: What happens if external thermal insulation is added on top of the bricks? Additional thermal insulation is probably standard by now. But do bricks retain their beneficial properties then?

And is there a reasonably neutral source on the topic of indoor climate, heat, and sound performance for timber frame versus brick versus solid wood?

Indoor air quality consists of temperature, relative humidity, CO2 levels, and pollutants. It is also influenced by drafts and—let’s say—radiant effects from cold or hot surfaces.

Modern houses are airtight. Walls do not breathe. Just to clarify this upfront.

Moisture moderation (for example, cooking or when 10 children rush into your living room causing a rapid increase in humidity) might be achievable with vapor-permeable walls. I would argue that the effect is minor and that other factors (room volume, carpets, curtains, upholstered furniture, plants) have a much greater impact. The influence of the wall is probably small.

Temperature (and comfort perception) is greatly affected by whether walls or windows are cold. This used to be the case, but no longer applies today. Thanks to low U-values or insulation (however applied), walls and windows are warmer on the inside. This feels more comfortable, so you can feel equally well at 20°C (68°F) as you formerly would at 22°C (72°F).

CO2 and pollutants can be controlled through ventilation, either manual or mechanical. (Regarding pollutants, additional reduction is possible by careful behavior.)

My conclusion: The construction method (wood, masonry, external thermal insulation composite system / ETICS yes or no) does not affect the (objective) indoor air quality. Whether or not there is a controlled mechanical ventilation system has a significant impact on indoor air quality. When there are large window areas, shading becomes an important issue.

As my predecessor mentioned... whether it’s sand-lime brick, wood, aerated concrete, or clay brick, with or without additional insulation, there is no impact on the indoor climate because all new buildings must be airtight anyway (the term "vapour-permeable" is just a marketing phrase and physically nonsense). This always sounds negative, but it actually has significant advantages compared to older buildings (some of which have already been mentioned... consistent comfortable temperatures everywhere, no cold drafts near windows due to radiant heat loss, and so on).

A ventilation system makes a big difference. Some people resist it, but anyone who has ever had one usually never wants to do without it again. Fresh warm air with the windows closed in winter and right after getting up, no need for additional airing if you don’t feel like it... priceless (ventilation systems are not really economical, but they offer a high level of comfort).

Thank you!

Is controlled residential ventilation not a hygiene concern (mold, fungi, germs)? I always imagine that fresh air from outside must be better than air that has been redirected multiple times through ducts. I always think of fully air-conditioned buildings, which are not necessarily healthy either.

Oooouuuh, diving straight into the wasps' nest. [emoji85]

Just take a look at a few houses in your circle of acquaintances that have a modern, centralized ventilation system and then decide for yourself.

In my opinion, it’s not comparable to air conditioning. The main difference from ventilating by opening windows is that no cold air enters in winter because the air is preheated and therefore comfortable. Otherwise, there’s no difference in air quality. By the way, a ventilation system doesn’t exclude opening windows if you feel like it... it just doesn’t force it. Especially at night in winter or similar times, you simply don’t want to have a window open but still want fresh air — that’s controlled residential ventilation.

I’m not aware of any hygiene problems in my circle of acquaintances. The vast majority of people also recommend not building without it nowadays. Of course, there are other opinions, especially online. Even if I had to disinfect the whole system every 5 years, I would always choose controlled residential ventilation again. I don’t know any older or newer houses without controlled residential ventilation that have anywhere near the same high air quality around the clock as houses with controlled residential ventilation.

Blah blah blah, if you have the chance, try sleeping for a few nights in a house with controlled residential ventilation. If then you say, “oh no,” just forget it. But that’s unlikely 😉

For example, Nordlys doesn’t like anything modern and is an old penny-pincher; he would even leave off the roof if he could 😉