Floor area ratio II, access paths, splash guard strips, terrace

Hello,

a frequently hotly debated topic concerns us, as even after hours of internet forum research we did not get a satisfactory answer. We are still awaiting a response from our architect.

We are currently planning our outdoor areas and would like to know:

1. To what extent does a splash protection strip made of, for example, decorative gravel, 50 cm wide including lawn edging stones around the house count towards the floor area ratio I/II?

I read contradictory statements here. Some argue that it is permeable loose material and therefore not a structural facility. Others say gravel is a construction product applied on the property for a specific purpose and thus a structural facility. Still others say that permeability and attribution to floor area ratio I/II do not always correlate 100%.

In our case, it is added that we deliberately left only a small roof overhang (50 cm including gutter) so that our roof overhang is not included in floor area ratio I.
We still need splash protection. Is this now "included," since the area above is sealed anyway by the roof overhang?

2. Terrace

We have planned a covered terrace. For this purpose, our house roof also extends "over" one spot and is supported. Since it obviously extends more than 50 cm, this part of the roof is also included in floor area ratio I. The terrace area under the roof thus no longer matters; you cannot count the area twice.

If we now wanted to enlarge our terrace beyond the covered area, it becomes interesting.

Does this count towards floor area ratio II, paths, ancillary facilities, terrace, or floor area ratio I, since it borders directly on the house?
Can someone answer this?

3. Development plan

Unfortunately, it does not regulate that much. However, the wording for ancillary facilities and access ways states: Driveways, paths, parking spaces, etc. may only be paved with permeable surfacing material.

Does that mean normal paving stones are completely ruled out? Grass pavers? Or are there permeable stones?

Otherwise, the development plan is very reserved and refers to the Land Use Ordinance and the Lower Saxony Building Code (we are building in Lower Saxony).

Thank you!

Others say that infiltration capacity and attribution to floor space ratio I/II do not always correspond 100%.

Viewed purely from the regulatory text, that is the case. Infiltration capacity is not mentioned in the Land Use Ordinance. However, since the protection against soil sealing was the reason for the legal amendment in 1990, this argument can be presented to obtain an exemption when exceeding the floor space ratio. Some development plans also grant favorable calculations when using certain materials.

1. To what extent does a spray protection strip made of, for example, decorative gravel, 50 cm wide including lawn edging stone around the house count towards floor space ratio I/II?

Strictly speaking, it counts towards floor space ratio I. But I have never calculated that. I have also never seen it. I have never heard of problems in this regard.

Does that count towards floor space ratio II for access paths, ancillary facilities, terrace, or towards floor space ratio I since it borders directly on the house?

Since the word "terrace" in your enumeration stems from your creative liberty and not from the regulatory text, it counts towards floor space ratio I.

Does that mean normal paving stones are completely excluded?

What is normal anyway?

Or are there infiltration-capable stones?

Yes, there are.

Oh, I see things differently in some points.

Regarding 1: Since the roof was already counted, the area underneath is not counted again.

Regarding 2: Tending towards the floor area ratio I. But usually nobody looks at that after the initial creation.

Regarding 3: There are indeed some. For example, there is a bamboo covering. Depending on the federal state, that then only counts as 50 or even 25%.

Splash guard: Was neither specified nor charged by us.
Roof overhang, covered terrace section. We were already very tight with a floor area ratio of 1, so our general contractor only calculated the 133 sqm floor area in the building application. It was approved. The submitted plans showed the clearly larger roof, which nobody at the building authority cared about. It’s always like that, said the general contractor engineer. If you are reasonable, they are too.
Permeable: We also have that in the text. Our driveway and parking area and part of our terrace therefore remained unpaved and were covered with pebbles. Our deal with the floor area ratio! Also saves stormwater fees. And looks good and is no disadvantage in practice.

Regarding 1: Since the roof was already counted, the area underneath is not counted again.

The roof is not counted due to the small roof overhang.

Regarding 2: Tendentially to the floor area ratio I.

If you leave out "tendentially," then we agree.

Regarding 3: Yes, there is.

That's what I said.

Depending on the federal state, this then counts only as 50 or even 25%.

The Federal Land Utilization Ordinance is federal law and can only be overridden by state law or local statutes where explicitly mentioned, in the case of floor area ratio calculation thus only by the development plan.

The roof overhang does not count if it is smaller than 50cm.