Developer: Are insurances required for additional contracts?

Hello everyone,
we are currently in the process of purchasing a semi-detached house from a developer who, of course, carries all insurances until handover. However, we want/will commission some trades separately, which the developer does not want to handle through their coverage. Do we need our own builder's liability insurance here or even additional insurances?
Thanks & regards

No. Depending on the trade, it makes sense to require a guarantee.

However, we want/will still give additional orders to some trades,

Does it have to :-( be?

which the developer does not want to handle themselves.

A risk the professional shies away from, does the amateur want to saddle themselves with it?

Do we need our own builder’s liability insurance here or even further insurance?

I wouldn’t want any fuss just because of the construction BG alone.

Depending on the trade, it makes sense to demand a guarantee.

Exactly: if the special-effects makers hold up the construction progress, I definitely don’t want to be in your shoes.

we are currently buying a semi-detached house from a developer,

A terraced housing complex (basically a semi-detached house is an end-of-terrace house) is a typical developer project. That’s something for builders who consider a self-made nameplate individuality enough. If you’re the type to “upgrade the bathtub to a jacuzzi,” then you’re in the wrong movie with terraced houses. That the 220 V plug doesn’t fit the 380 V socket is not a bug but a feature. “Developer” means “fire and forget” – not spoiling the broth with too many cooks.

Overall, we are completely satisfied with the standard semi-detached house, regardless of the fact that there have been no plots of land for a self-built single-family house in recent years and this is not expected to change in the next approximately 2 years. In addition to the standard, the primary desire is for electrical wiring via KNX bus and a photovoltaic system with storage as a supplement to the heat pump. We are supposed to handle these two points ourselves, which is the reason for the question.

Besides the standard, the primary desire is for electrical wiring via KNX bus and photovoltaics with storage as a complement to the heat pump.

But these are precisely two delicate points: not every electrician masters the home automation bus systems, and a significant intervention in the standard heating, ventilation, and climate concept of the developer standard (never change a running system) does not make me optimistic about having the usual subcontractors of the developer handle it. And I would especially advise against letting a second cook spoil the broth in each case. Can't one manage with manual light switches in a transitional property for the few years in which the turbo for the heating technology doesn't pay off anyway?