ᐅ External thermal insulation system (ETICS) installed by a professional company! Additional costs for a few extra centimeters of insulation?

I am having an external thermal insulation composite system (ETICS) with EPS 035 and 14 cm (5.5 inches) installed by my turnkey builder in about one month. This will be carried out by a company located roughly 6 km (3.7 miles) away. I have now asked this company what it would cost to increase the insulation thickness by an additional 2 or 4 cm (1 or 2 inches). Regarding labor effort (the exterior window sills are sufficiently deep, etc., and already installed), there should be no additional work involved.

The company has offered me an extra charge of 4 euros/net per cm to increase the insulation thickness. Where are the company owners? I am curious what you typically charge for these extra centimeters. I find this price very high!

Thank you in advance.

The material costs approximately €1 per centimeter (+ longer doweling). A nice extra profit for the construction company...

14cm (5.5 inches) is more than enough. The savings in heating costs with 16cm (6.3 inches) or even 20cm (7.9 inches) are minimal at best.

Nordlys schrieb:
The savings on heating costs with 16 cm or even 20 cm insulation are minimal.

The U-value calculator shows that adding 4 cm (about 1.5 inches) more insulation (to a total of 18 cm or 7 inches) costs €4 per cm (€16 per m²) and, with heating energy costs at €0.07 per kWh, would require at least a 20% annual increase in costs to break even within 15 years.

Even if offered a price increase of €8 per m² (half the original cost), at a 5% annual price increase it would take 20 years to amortize.

At a pure material cost increase of €1 per cm, with a 5% yearly price increase it still takes nearly 14 years. This could theoretically be considered if paid from equity, but practically there are likely better investment options.

In short: Nordlys is completely right – it’s not worth it.

It's not a question of economics for me! What I'm interested in is what a fair additional cost would be for installing 2 or 4 cm more insulation.

What becomes interesting, however, is the reduced consumption of my heat pump (according to the Energy Saving Ordinance, about 12,500 kWh/year (13,485 kWh/year) for heating) in terms of sizing the photovoltaic system. That is why these considerations are being made.

BaueBaueHaus schrieb:
Turnkey builder

Do you have an alternative?

Then it makes sense to think about it.