Thermal insulation of gable roof

Hello everyone,

I want to insulate our roof and have already calculated a few variants, both the U-value and the financial aspect. Unfortunately, I now have several variants and cannot decide.

Here are the key data:

- House built in 1950
- Roof 2008

Roof structure:
- Tiles
- Battens
- Counter battens
- Delta foil
- Rafters 120mm x 75mm

Variant 1:
- Insulation wool WLG035 120mm between the rafters
- Vapor barrier
- Battens
- Gypsum board

Variant 2:
- Insulation wool WLG035 120mm between the rafters
- Battens
- Insulation wool WLG035 50mm between the battens
- Vapor barrier
- Gypsum board

Variant 3:
- Boards 30x160 sideways on rafters
- Insulation wool WLG035 160mm between the rafters/boards
- Vapor barrier
- Battens
- Gypsum board

Variant 4:
- Boards 30x160 sideways on rafters
- Insulation wool WLG035 160mm between the rafters/boards
- Battens
- Insulation wool WLG035 24mm between the battens
- Vapor barrier
- Gypsum board

Maybe someone can take a look and give their opinion – I am grateful for any tips. Maybe I have planned something fundamentally wrong. I cannot assess the values regarding moisture. I do not want to make this house an energy-saving miracle according to the energy saving ordinance, but insulation is better than none.

Thank you very much.

Variant 2

v.g.