Building savings - does it make sense? If yes, what amount?

Hello,
I would like to buy an apartment in a few years (3-4).
Is it worth concluding a [Bausparvertrag] for this? This would secure a relatively low interest rate for me.
If yes, what amount would you recommend and why? And what should be particularly considered?

about the amount you need

No, that is generally not worth it. 1. You usually do not reach a large allocation-mature amount in that time 2. The closing costs are generally high

To make a well-founded statement, a few more details would need to be known. Particularly important are the planned budget and equity.
In the short term, you will hardly be able to cover a large part of the financing through a [Bausparer]. Accordingly, a small [Bausparvertrag] would be more suitable to improve the loan-to-value ratio, since the [Bausparkredit] usually counts as equity. However, these loan-to-value ratios and the advantage you gain from them naturally depend on the specific bank and property.
Don’t forget that with the [Bausparvertrag] you also have relatively high closing costs. The allocation can sometimes be difficult to plan, especially with a short-term [Bausparvertrag].

In 3-4 years you will not receive an allocated building savings contract, it runs for at least 7 years.

So we have taken into account 2 building savings contracts from 2010 in our financing, specifically for the follow-up financing in 2025. This gives us the comfortable situation of being able to choose whether we only take out our capital or whether we take the loans at interest rates of 1.95% and 2.95%. For immediate financing, it probably doesn't make sense since it will no longer be ready for allocation. However, you can secure the interest rate for the future in case it should rise and thus partially protect your remaining debt later on. But you must also be aware that you have to continue contributing to it alongside your financing for this to work. Therefore, do not choose the rate too high.