New construction preparation for future experiences

Hello,

Construction is supposed to start at our place at the end of October/beginning of November.

We are building Kfw55 with a gas boiler and a 5m2 solar system for hot water with a general contractor.

I would like to make preparations for a possible photovoltaic system that might be installed later.

Is it best to lay an empty conduit from the attic to the utility room for this, or should the electrician run a corresponding cable without connecting it?

I would like to make the house relatively future-proof with simple means. We have a gas boiler; I have seen in the specifications of another general contractor that they leave two pipes for a later installation of a heat pump in the utility room. Are there any other things that can be done in this regard that require little effort now but could have great benefits later?

I would also like to have a 400V line, or at least an empty conduit, installed to the carport, as I assume that electric cars will become standard in the next years or decades.

Thank you!

Take 2x 20mm empty conduit. The cables must be oriented according to the power output of the photovoltaic system, and who knows how large your installation will be later.

Thank you very much for the quick response!

Otherwise, I would have simply taken the cable with the largest affordable cross-section.

Is it worth getting a larger storage tank for the gas boiler right away in case modules for heating support are retrofitted later? If gas prices skyrocket or there are high subsidies, it might pay off at some point.

No. No storage for heating support. Not worth it - even with gas prices twice as high.

Depending on the size of the photovoltaic system, you probably also need to size your electrical panel accordingly - you should also provide space in the technical room for any battery and possible other equipment.

We are only getting the solar system for hot water to achieve KfW55. With the €5,000 repayment grant and the subordinate loan, it is worthwhile for us.

These are probably all things I can discuss with the electrician during the sampling.

Is it worth having a 400V line installed to the carport right away, or is an empty conduit more sensible?

I think you might as well have the cable installed right away... the price is of course steep there too, but for a €10.50 saving I wouldn’t want to bother with the hassle later.