Optimal height of finished floor level to street edge

Hi,

We received our building permit two weeks ago; it states under conditions that it is recommended to raise the house by another 25 cm, but it is only a recommendation.
However, it is somewhat unsettling. At the moment, it appears that the plan is for the top edge of the finished floor to be 15 cm higher than the top edge of the street.
I actually considered that sufficient.
The street is about 10 m away and slopes towards the other side of the street.
What do you think about it?

Daniel

15 is not that much. I think my iPad is about that wide. But 40 right away? We have one step at the front door. I think that is enough to keep floodwaters out. I just don't know how high such a step is. It doesn’t have 40. Karsten

Two weeks ago we received our building permit, which includes a recommendation as a condition to raise the house by 25 cm, but it is only a recommendation.

Does that mean in other words that the permit applies to the house as planned and at the same time also allows it to be raised by up to 25 cm?
Is there no reason given for the recommendation?

I consider the height ratio between the sewer and the house drain to be a more critical factor than that between the street and the floor.

As a precision engineer, I would be satisfied if the raw floor level was at or above street level.

We have a step at the front door. I think that is enough to keep out floodwaters. But I don't know how high such a step usually is.

Fifteen to eighteen is what it usually is.

19 cm are considered very comfortable as a step height.

17 as the rise and 29 as the tread is the golden ratio for stairs. 19 as the rise is also acceptable. Or 20...

Does this mean in other words that the approval applies to the house as planned and simultaneously also set up to 25 cm higher?
Does the recommendation have no justification at all?

I consider the height ratio between the sewer and the house drain to be a more critical factor than that between the street and the floor.

As a draftsman, I would be satisfied if the raw floor was at or above street level.

It will mostly be between fifteen and eighteen.

It only states that it is recommended because of rainwater, etc.

It must be said that the plot or the 10 m in front of the house would definitely lie lower than the street, about 17 cm, adjusted to the 4 m green strip of the city that runs next to the street along our property boundary.
And the house would then stand about 35 cm higher from the property boundary, or approximately 2 steps.
We would be exactly at the neighbor's level, including the same finished floor height.

I also have to say that to achieve these heights I already have to fill the area for the house and later the area in front of the house about 35 cm above the base plate.

If I follow the city's recommendation, I have to fill 60 cm and would then be on a hill compared to the neighbor.