Is central control for shutters retrofittable?

A deep box can be helpful. Additionally, sometimes there is the problem that not all connections are available at the actuator location. For example, with Homematic you need the "N" which is not always there. If using radio, then do it properly right away and not only in one or two years.

If a Homematic actuator and switch/button are to be used per roller shutter, then a deep 68mm box alone is not enough. Then the actuator either has to be placed in a second box or the actuator goes into the roller shutter box. However, to retrofit this means that the empty conduit between the switch box and the roller shutter box, as well as power including N, must also be present at another switch box.

Rademacher is also worth taking a look at. The actuators can be installed in a (deep) box or, for example, in the roller shutter box itself. Or you can use the Rademacher switch including timer control, etc. Everything can then be centrally controlled with a remote control or, when using the HomeServer, also from a smartphone/PC.

There is a roller shutter control system from heytech that can be retrofitted centrally. However, the prerequisite is that all 5 wires from the roller shutter to the fuse box are routed. The system costs approximately half of your price.

Retrofitting is quite simple. For example, with z-Z-Wave: - 15 flush-mounted actuators at approximately €45 each. - Central unit (I estimate €100-300), alternatively Raspberry PI (~€130). Of course, this can then be used for all other automation purposes, so the cost is not only for the blinds.

Total cost is about €800. Astro function is usually included directly (for example, I use OpenHab 2 with a Raspberry PI, where control based on astro is directly possible without additional costs).

Homematic is, for example, in a similar price range, but z-Z-Wave has the advantage that it is not proprietary, especially gaining a lot of traction in the USA and various manufacturers are jumping on the bandwagon. Installation is simple.