ᐅ What type of masonry construction do you recommend for exterior walls?

For self-build projects, aerated concrete is basically the classic choice. It would also be compatible with calcium silicate bricks indoors. Poroton Dryfix is another option worth considering.

Basically, it doesn’t really matter whether you choose aerated concrete or bricks. Both can achieve the required insulation values without external thermal insulation composite systems (ETICS) if you use the right thickness and type of block. A Poroton T7 reaches a lambda value of 0.070 W/(mK), and Ytong ThermUltra also achieves lambda 0.070 W/(mK).

In the end, most of the heat is lost through the windows and ventilation anyway, so there’s no need to overdo the insulation value of the walls.

I would always build with aerated concrete and plaster, maybe next time with 42 or 49cm (16.5 or 19 inches) instead of 36.5cm (14.5 inches). But if the general contractor had used bricks like T9 or T8, I wouldn’t have minded either.

An advantage of aerated concrete is that when you drill, you don’t get red dust that dirties the nice white wall and spreads everywhere. A definite disadvantage of aerated concrete is that you shouldn’t plan to hang heavy loads on the external walls. According to the datasheet, a 14cm (5.5 inches) Tox plug in PP2 aerated concrete holds only about 40kg (88 lbs). Alternatively, you can install heavy-duty anchors directly.

ETICS can achieve higher insulation values, but the downside is that almost nothing heavier than a mailbox can be securely mounted.

And… doing it yourself? The shell construction? Good luck.

Oh, and the interior: aerated concrete PP4 is fine, right? Most sound passes through the doors and, surprise, through the suspended ceiling. If you’re building with calcium silicate blocks, you’ll need a reinforced concrete ceiling up to the roof and soundproof doors for proper sound insulation.

The building plot has enough space for every brick.

hanghaus2023 schrieb:

Your preferred contractor often uses their own system.

You misunderstood something. The original poster does not want to be restricted by a “this-is-how-we-always-do-it” approach because they are focused on the most cost-effective and self-determined method. Additionally, they are probably more knowledgeable than a general contractor and mason due to their self-study during their first house and continuous learning, however that may be.

Buddy90 schrieb:

In your opinion, what is currently the most cost-effective wall construction that meets the energy saving regulations?

Aerated concrete monolithic block calibrated 365, best processed by a single person.

motorradsilke schrieb:

We built with Liaplan blocks. They are easy to handle alone. The masons also told us that some people do this: they have the mason lay the first row and then continue building themselves. They are only glued together.

First row and/or corners—there are different preferences for this. Aerated concrete is the lightest block, which also makes it suitable for large formats. If the block is somewhat heavier (Liaplan’s bulk density is probably similar to pumice), it is less challenging for inexperienced users to handle: either each individual block is heavier and thus more tiring to set and adjust simultaneously and/or helpers or positioning devices are needed, or each block is not heavier (but correspondingly smaller in size). Both options negatively affect work performance. Whether the adhesive is called bonding cream or mortar is largely a matter of preference—in any case, plan blocks only allow 1 or 2 mm (0.04 or 0.08 inches) thick bed joints, and the vertical joints remain dry (here, interlocking replaces the adhesive effect).

Porous bricks are even heavier = not very beginner-friendly (this especially applies to the filled versions) and unfilled versions are not really a comparable alternative.

wiltshire schrieb:

If I were to build the walls myself, I would look into a Neopor ICF formwork system.

For inexperienced builders with at least some observation experience, the even lighter insulating formwork blocks do not offer a noticeable advantage over aerated concrete. One downside is that you have to get somewhat familiar with the system. The basis here is not an octameter grid but a decimal system with full (5 cm (2 inches)) and half (2.5 cm (1 inch)) increments for cutting lengths. Mixing this with masonry block formats can result in fiddly adjustments. The term formwork "blocks" was coined for popular understanding; in fact, they are even less like blocks than aerated concrete, which at least is a type of artificial stone foam. The formwork block becomes a wall material only through its reinforced concrete filling. A sensitive point occurs if novices pour the delivered concrete mix too fluidly (usually: too much plasticizer) and especially if it is overfilled. I wrote a post about this on "Bauen jetzt" under the keyword "bestgefahr," because this can cause problems for the formwork block "wrapper."

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Here the nonsense just continues. If a layperson simply goes ahead without familiarizing themselves with the subject, it will fail with all known systems. From sand-lime bricks to aerated concrete blocks to the systems using expanded polystyrene from companies like Kern-Haus. There is no foolproof system that allows building a house without any knowledge.

But if you take an hour to read and don’t have two left hands—good grief. Aligning aerated concrete blocks with a string line and a spirit level, then bonding them row by row, is not rocket science. A layperson will simply take about five times longer than a professional, especially at first.

However, no craftsman is a natural talent. It’s primarily practice, practice, and more practice. Welding comes from “sweat,” as my trainer used to say.

And to emphasize once more:
You learn absolutely nothing by just watching. That’s my experience from 25 years: apprenticeship, university, and a solid 16 years working in special plant construction. You only learn when you do something... then questions arise, then problems come up.