ᐅ Renovating an Older Building: Which Insulation Is Suitable for Exterior Walls and, If Needed, the Basement?

Hello,
I will soon start renovating my parents’ house.
Built in 1954 with brickwork, with a 1975 extension made of aerated concrete blocks, and a basement. The location used to be a marsh area, but the groundwater level has since dropped further. The basement is dry and there are no moisture issues.
I have an appointment with an energy consultant in two weeks, but I don’t want to go unprepared. Also because some specialists can be quite one-sided in their advice.

When replacing the pipes, I plan to excavate around the building and insulate the foundation at the same time.
From what I understand, the typical setup is masonry – damp proofing – XPS or a similar material. Is that current best practice?
What types of damp proofing are available?

Regarding the rest of the masonry, I’m not completely sure.
At a trade fair, I saw Poroton WDF blocks, which seem reliable, but their insulation values don’t appear to be great, especially considering the cost. Am I right or wrong about this?
I’m not keen on glass wool or rock wool, so I’m interested in wood fiber insulation boards like Steico or Gutex as an alternative.
Are these any good, or are there other options?

Of course, I know a professional will need to examine everything in detail, but I would be interested in your experiences to avoid any risk of mold developing in the building later on.

Thanks

Do you want to insulate from the inside or the outside? Will the basement be used as living space? What is the ceiling height in the basement? Is there a plan to install drainage?

Hello,
insulating from the outside, not suitable for living, ceiling height just over 2 meters (6 ft 7 in), the basement extends about 1 meter (3 ft 3 in) above ground level, and yes, a drainage system will be installed afterwards.

Okay... From the outside, you need to consider what appearance you prefer. There are options for a curtain wall facade, which allows for good DIY insulation. You can also use ETICS (External Thermal Insulation Composite Systems), either with plaster or glued facing bricks. There are also prefabricated panels that can be installed like a puzzle. So, be clear about what you want before deciding. The roof overhang is also an important factor here. Often, the roof needs to be extended accordingly.

For the basement, I would only waterproof it from the outside without adding insulation. You will anyway extend the facade insulation over the basement ceiling. Then I would insulate the basement ceiling, for example, with aluminum-laminated PUR foam. It has good insulating properties even at a low thickness. It can be glued, adheres well, and costs about 1000€ in DIY work.

@Joedreck: Well summarized.
An additional note on roof overhang. It might be worthwhile to keep the roof as is and instead use a high-performance insulation. With a vacuum insulation panel, between 80 and 100mm (3 to 4 inches) is sufficient to meet the energy-saving regulations (thermal conductivity rating 22).

And what about dew point, condensation, "breathing," and things like that that you always hear about?
The gable on the first floor is already insulated with Styrodur or a similar material, so there is no mold, but I also know others who had black mold on their walls after insulation, which is why I wanted to gather some more impressions.