ᐅ Results – Does Insulation Fulfill Its Purpose? Exterior Thermal Insulation Composite Systems (ETICS) – A Myth?

Hello, do you have any results yet on whether the promised savings were achieved?
For example, an energy consultant calculated a 35% heating energy savings for an external thermal insulation composite system (ETICS / WDVS) on an older building.
How much have you or someone you know actually saved?

Rental Apartment Attic
14cm (5.5 inches) of over-rafter insulation... nothing was promised, but instead of 80 euros per month plus a small annual adjustment, there was even a refund of 35 euros per month.

So in this particular case, savings > 50%.

However, the rent was also increased by 50 euros. So, overall for the tenant, it’s a break-even situation.

How did the indoor climate change during the hot summer?

In my attic apartment (built in 1965), the roof was replaced a few years ago with an added 12cm (5 inches) of insulation; previously, it was uninsulated. In winter, it is now noticeably more comfortable (and slightly more energy-efficient), but in summer, it becomes unbearable. It was always very warm before as well (sometimes up to 45°C (113°F)), but it usually cooled down well at night. Now, if the sun shines strongly for only one or two days, it stays cooler, but during a real heatwave in midsummer, the temperature inside rises to around 40°C (104°F), and I can no longer get rid of the heat at night just by opening the windows...

The result for me is energy saved but comfort reduced (in summer). If I want to keep it cool now, I would need an air conditioner, which would negate the energy savings. It’s different in my house. Although I don’t live there yet, I spend a lot of time working inside. It stays comfortably cool even in summer.

That’s why I think the overall concept has to be right. Retroactive changes are always just a makeshift solution.

Keep in mind: when adding waterproofing afterward, it’s a good idea to install a few controlled ventilation systems for living spaces...

What is best for a self-builder ... panels made of pure expanded polystyrene? Solid roof .. traditional roof frame with insulation both between and above the rafters.