I received the first tile quote today. €136/m2 for floor tiles excluding the tiles, but including consumables was estimated. That is simply twice as much as I had estimated. Now it's time to get further quotes.
What you are doing here is simply wishful thinking. Take another look at the list ( ). Where do you want to do more own work? Heating and sanitation? Or save 15k on the electrician? You might shave off another 5000€, but certainly not 20% of the total budget.
At first glance, what comes to mind is: Walls and ceilings don't need 30,000, floors don't need 10,000, outdoor facilities don't need 15,000 if you do them yourself. You can easily save 40,000 there. Provided it is flat land. Then you lay the heating pipes yourself, chase the grooves for the electrician. That's another 5000 to 10,000. That's a total of 20%.
So I consider floors under 10k unrealistic. I paid 16k for walls and ceilings incl. fleece and painting in Q4, from a painter friend and his team, normally that would have been significantly more expensive... it was around 650m² I think.
The outdoor area also cannot simply be written off at under 15k. If you, like us, have no flat surface, no right angle, you won't get far with just EL and everything cheap at 15k
We primed our 103m2 with 2.5m height including ceilings for ~2500€ and applied textured paint on q2. The floor cost us 3000€ all in, vinyl everywhere including skirting boards. So it can definitely be done cheaper... having it done is just expensive.