Hello,
Getting a plot and then calmly looking for a house sounds good - that's how we did it too.
Regarding financing: How secure do you consider your job?
When calculating costs, better estimate higher and don't forget the incidental costs, such as property transfer tax, notary, possibly realtor, for house construction connection fees, soil survey (preferably BEFORE) plot purchase, etc.
Purchase the plot preferably from a municipality or city. It's best to call now all the municipalities that could be considered and ask about new development areas that are planned/will be coming soon. This saves realtor fees and the prices are more realistic than on the free overheated market. We also had success this way.
Important when buying: location, location, and quality of the plot (soil survey!!!)
Regarding own work: Yes, you can save a lot of money. With a lot of own work, it is advisable to build with an architect who also supervises your work during the execution phase. But be aware that this path is labor-intensive. You have to think about every trade within the scope of the tenders.
Alternatively, you can build with a construction company at a fixed price. Advantage: fixed price; with an architect it can sometimes get more expensive. Caution: definitely obtain references. Go to new development areas and talk to other builders about their experiences. References mentioned by construction companies are less useful; they will hardly tell you problem cases and somewhere it once went well even at the last bad company.
When you have a company and an offer: check carefully and preferably have it checked. Technically and legally! There are associations and organizations with corresponding experts who do this for a few hundred euros. It pays off. Independent construction supervision during the execution phase is also highly recommended. Defects are often not recognized by laypeople.
Finally on finances: Save as much as possible. The more equity, the better the bank conditions + the less interest you pay. In addition, you notice where your monthly pain threshold is.
When choosing the financial institution: Take two weeks off, inquire at at least 5 banks, savings banks, and at least one credit broker. Take all offers and have them checked by the consumer advice center (approx. 250 euros) and advised on what is best for you.
So, that's it for now.