ᐅ Eaves height of 3.5 meters for a full storey – practical roof design?

Hello everyone, my wife and I have reserved a plot of land in a rural village. We are very interested in building there since we come from this region. We have taken a closer look at the zoning plan and find the requirements quite strict. We are currently trying to find a practical solution. First, here are our requirements:
- Living area of approximately 150+ square meters (with at least 3 children’s bedrooms)
- We definitely want a basement (initially not for living, possibly later 1-2 rooms with natural light due to a slight slope)

According to the zoning plan, the following points apply:
- 1 full story, floor area ratio and total floor area ratio 0.2 (our plot is 700 square meters (7,535 square feet))
- Ridge height 6.7 m (22 ft) (The maximum building height is defined as the ridge height (RH), the highest point of a structure. This is measured from the reference level at the ground floor – finished floor height (single-family house). RH max = height of the parapet for flat roofs.)
- Eaves height 3.5 m (11 ft 6 in) (The eaves height (EH) is measured at the highest point of the intersection between the external wall and the roof covering/flat roof from the set reference point (single-family house).)
- Reference point: Ground floor – finished floor height (single-family house). All building heights are determined from the single-family house reference point. The ground floor of a building is considered a full story according to § 20 of the land use ordinance. Excavations and fill required to achieve the chosen ground floor level are permitted.
- Roof types: gable roof/gable roof with dormer/pitched roof/hipped roof 22° to 30° / flat roof 0° to ≤ 5°

We have already considered several options for how to implement this – in terms of maximizing living space with minimal extra costs, such as bay windows or dormers.

At this point, we are leaning towards a gable roof to use at least part of the upper floor effectively.

Do you have any ideas whether this could be done with a flat roof, for example? (Unfortunately, we don’t have an architectural background, so we don’t fully understand what is required for a flat roof to be allowed up to 6.7 m (22 ft) in height.)

We appreciate any help and support to make our dream come true! Thank you in advance for your assistance!