Purchase financing: how much equity (with the low interest rates)?

Please do not forget the capital gains tax of 25% in the calculation, which somewhat relativizes the profits in the markets (but also what you now achieve for the equity in a stock sale). I had a similar issue and then decided to optimize for the lowest possible interest rate. This resulted in almost 50% equity over the total costs, and the tax office will be happy next year about a high capital gains tax back payment (the stocks were abroad, so it was not automatically withheld). But I consider the markets overheated anyway and expect a correction downwards.

Good point regarding the 25%.

Nevertheless, it doesn't change anything about...

Off-topic:
I think that if there is any indication that corona is under control and supply chains are working again, I rather see an upswing; so much capital has been and is being pumped into the market, it has to go somewhere...

Equity approximately 300k (90% in stocks).

Stocks in a portfolio are not equity. Equity is the liquid funds that you include as a component alongside the loan in home construction financing.
A stock portfolio is not liquid.

Now I am partly also a scaredy-cat and if the markets crash in 10 years

… exactly for that reason.

Saving money is great, but what are you saving for if you do not want to spend it on your own house?

My thinking.

I just want to let my money work so I can possibly retire earlier

See Tassimat’s remark.
That’s a catch-22: either finance and repay over a longer period or make part of it liquid and position it as equity.

would be an economic disaster.

You are practically working towards that if you don’t occasionally take profits out of the portfolio.

Stocks in a portfolio are not equity.

Whatever it is - it helps to get better interest rates. It is an investment form recognized as solid, which can be managed with little risk with some basic knowledge.

Now I am partly a scaredy-cat too, and if the markets crash in 10 years and interest rates rise (and maybe hell freezes over), then of course it would be bad...

If markets crash, that is no problem as long as you don’t have to sell. In principle, you can profit from any market movement direction – but I would only use money from “play money” for that. If you plan the investment in a portfolio to use it at a certain time X for further home financing, then do not hold the portfolio until that date, but find a favorable time to exit beforehand. That reduces the risk of having to sell at an unfavorable time. The bigger problem is usually greed and the desperate attempt to find the absolute best point to buy and sell.

Please don’t forget the capital gains tax of 25% in the calculation

Good point – it makes sense to cleverly use the tax allowances, take profits here and there and reinvest.

Saving money is great, but what are you saving for if you don’t want to spend it on your own house?

For an investment in own ideas, to pass on to descendants, for godchildren, donations...

I don't know if I mentioned it, but with 10% equity and a 15-year fixed interest period, I would pay 1.1% interest. So quite manageable.

I don't know if I mentioned it, but with 10% equity and a 15-year fixed interest rate, I would pay 1.1% interest. So quite manageable.

I think the idea you have is great and I would do something similar. I have a similar amount of equity and salary. If the capital market continues to rise like this, then in 7 years you will have a portfolio twice as large. With a bit of luck, the house will almost be yours by then. After 10 years, as far as I know, you can terminate the loan and look for a new one. That would be a good time to repay part of the stock assets through the loan. But I wouldn't do it completely. The leverage effect is good for building wealth.

Of course, you bear the risk that there is an economic crisis that endangers your job and triggers a global stock market crash. Therefore, you should also consider how future-proof your job is and how crisis-resistant.

Now I'm partly a scaredy-cat and if the markets crash in 10 years and interest rates rise (and maybe hell freezes over), then that would of course be bad...

Interest rates have been steadily falling over the past decades. My opinion is that with Bitcoin and co., interest rates will even move further into negative territory. If the ECB and FED were to raise the key interest rate too much, it would also weaken the economy, so they do it slowly.