Single-family house planning with a granny flat - ~230m² - basement - gable roof

Yes, we had this idea as well. However, visually it’s not that eye-catching or what I’ve seen so far. The plot is 22 m wide and 51 m long. Very flat, so no slope. On the left is a two-story single-family house with a gable roof. On the right is a large green meadow, initially undevelopable.

If you want to do all this in compliance with the KFW conditions, you have to change the access situation.

The following is stated in the leaflet regarding KFW 153:

"Wohneinheiten are rooms located within a closed connection and intended for permanent residential purposes in residential buildings, which enable the running of a household (room, kitchen/kitchenette and bathroom/toilet)."

If I look at your floor plan, you want to create a connection to the main residential unit via the door on the upper floor. I don't even want to talk about the access situation on the ground floor (creating your own front door only later). I have spoken with our architect about it and there are tricks to make it work. However, you also have to consider the costs that this will even cause. In most cases, the measures required for a second residential unit easily consume the financial resources that you have available through the second promotional loan as additional funds.

Just the second staircase alone swallows at least a mid four-digit amount, which simply would not be needed without a granny flat. If I were you, I would reconsider that. Above all, I would avoid the second staircase INSIDE the building. Simply make a window at the future entrance on the upper floor, which can later be supplemented by a front door + external staircase.

: You are right that a granny flat is not a cheap undertaking. We already have an offer with and without a granny flat. Price difference about 18-22,000 euros. Could you maybe show me an outside staircase variant that looks neat?

Can you perhaps show me an exterior staircase variant that looks decent?

Just google, for example, exterior staircase for granny flat or similar. Many examples - whether beautiful is in the eye of the beholder. But it makes the house look significantly better from the inside ;)

We will create a 2nd residential unit directly, possibly also with a 2nd entrance right away. We want to do everything cleanly and in compliance with the law. My son will then live in this granny flat... But we are creating a 2nd granny flat. As I said, it just won't be rented out immediately. We want to do that later when the little one is no longer little and becomes independent. But we meet the requirements, possibly we have to make a 2nd entrance door instead of the window directly. What do you mean by € too late?

You should have this checked very carefully whether, under your conditions, subsidy fraud must not be assumed.

One thing are the mandatory structural obligations; another is the use. You want to provide subsidized living space to your _child_ and thus to yourself. Today you say you will rent out the granny flat later – but when is later anyway? What if your living circumstances change, and it never gets rented out?

I do not see that you would be entitled to a subsidy for the granny flat.

Building expert on the go

I believe only a second residential unit needs to be present. How it is actually used is not left to the owner?

As far as I know, all structurally necessary measures must be carried out. (Eigener Eingang, Brandschutz/Schallschtz (betrifft auch z.B. Lüftungsanlage), Anzahl Stellplätze etc.)