However, you also have to look at whether the additional interest that accrues for securing the interest rate in, for example, 3 years, ultimately pays off or how big the difference is. In addition, consider other factors as well.
1) Currently, you rent - the money is gone and you will never see it again. But if you move into your own house faster, you put the "rent" into your own house, basically into your own "pocket." With rent, you only fill your landlord's pocket; yours remains empty.
2) The costs for the house can also look completely different in a few years, just like the personnel/labor costs, etc. All things you have to invest in or buy for your house.
Take all this into account and consider it. Currently, there may seem to be an advantage or this may seem like a good solution, but who knows how the market and the cost structure will change in the coming years.
In my opinion, building a house is always associated with a bit of risk because you never know what will happen. But that is the case in life in general...
I always tell myself: "If you want one thing, you have to live with the other."