Bricks: Are differences in the thermal conductivity value of 0.03 noticeable?

If I still have a storage system, I ask myself whether the higher heating costs are not reduced or even eliminated by the photovoltaic system?

Building on my previous post, I would even leave out the photovoltaic system (but prepare what is necessary), in order to achieve significantly better insulation of the entire house. With the absolutely sensible photovoltaic system, you often generate electricity that you wouldn’t even consume with better insulation.
I have a 10 kW battery, that’s nice and also fun, but it’s certainly no gamechanger.

Since money already plays a Rolex for me, I want to implement the financial and emotional, that is, truly noticeable, measures as well as possible.

Instead of believing that this only concerns me, one should rather remember the song of the good old Roy Black here: "You are not alone."
The long-term sensible use of construction measures in relation to the available budget probably applies to 99% of all builders.
Maybe you’ll post your project here sometime and the community will find savings potential where you haven’t even suspected it so far.

Maybe you’ll post your project here and the community will find savings potential where you hadn’t suspected it before.

You only need to read the virgin threads of other newbies to realize how many of the other fellow building dream “sufferers” also get bogged down with peanuts at the beginning or try to solve it like math problems (first factoring out the known variables and seeing where you can simplify). But house planning is different after all.

Since a LW heat pump is planned, the heating costs are on the electricity bill. If I also have a storage unit, I wonder whether the higher heating costs can be reduced or even eliminated by the photovoltaic system?

We have a house, heat pump, storage, sauna, and an average electricity consumption for 2 people. Since we knew this beforehand, the photovoltaic system and storage were designed based on these parameters. Mathematically, we still have a monthly charge of €8 on average over the year due to the Renewable Energy Act surcharge and saved electricity. Plan your house well. Energy can then be designed accordingly.