Construction costs are currently skyrocketing

As someone already mentioned above, it currently feels like all solar installers are fully booked, and if anything, you often get a very expensive offer.

A regional provider here currently has 160 inquiries on the table and expects lead times of one year or more with two installation teams (from inquiry, about 8 months from order). Last year, delivery time was a factor; now the waiting time for installers is longer. Prices are, for example, around 21.5k net for 9.84 kWp / 7.7 kWh storage, fully connected and registered with scaffolding costs. VAT is waived at least in 2024 - so you are actually already too late for that.

In a large bargain portal, a self-assembly kit with 25*410 = 10.25 kWp modules, inverter, 9.6 kWh storage and Smartmeter is currently offered for €13,200. If you roughly subtract storage at about €5,000, you end up at €8,200 or €800/kWp for the material. Plus cables, mounting kit (roughly €100/kWp) and labor.

I don't know what problems you have with photovoltaics.

In a large bargain portal, a DIY kit with 25*410 = 10.25 kWp modules, inverter, 9.6 kWh storage, and smart meter is currently offered for €13,200. With storage roughly calculated at €5,000, you end up at €8,200 or €800/kWp for the material. Plus cables, mounting set (roughly €100/kWp), and labor.

Do you mean the one that starts with T and the website is green?

There was recently a 10 kW with rails, cables, and inverter available for €6,300 for pickup.

Jasolar modules
Inverter from Grovatt
etc.

In view of rising loan interest rates and expensive materials, property buyers and builders in the housing market currently have to bring significantly more money. Owner-occupiers still contributed an average of just over 111,000 euros of their own funds to the construction or purchase of a property in 2021; the amount increased by more than a quarter to just under 140,000 euros last year, according to new figures from the real estate financier Hüttig & Rompf. In the final quarter of 2022, the amount for the properties brokered by the company was almost 149,000 euros.

The equity share of the total costs for builders and buyers, which averaged 562,000 euros, rose from 20 percent in 2021 to almost 25 percent last year, according to Hüttig & Rompf. In the last quarter of 2022, it was already 28 percent. "This is necessary in order to even be granted financing by banks, which have significantly increased their requirements in recent months, under reasonable conditions." Many banks review loan applications more critically in view of rising interest rates and high inflation and have increased the flat rates for living expenses.

I honestly don't think it's a problem if there is now more thorough checking. Not everyone can and should afford any financing they want. In this context, banks take on the role of the spoilsport, having to protect some FOMO colleagues from themselves.

See the thread here recently, where someone with an income of 5 or 6k€ wanted to carry a 3k€ installment.

Current construction costs:

Remove old plaster, remove window sills, dispose of everything, 14 EUR / m2
Apply base plaster, apply top plaster, filling compound, filling, sanding, lime-cement Q3: 62 EUR / m2
Screed at least 5 cm:, incl. edge insulation strip: 41.7 EUR / m2
Floor insulation (old building), WLG 035, various heights due to cellar vault: 55 EUR / m2