I am coming here over from LTT, after watching Linus test out your new dimmers.
While I do not live in Europe (not only we are not part of the EU, we are also on a different continent), our standards are mostly based upon EU standards, so this is the best place for me to chime in.
Personally, I would recommend a combination of all three kinds, with removable plates (but the actual modules, and yes, it would be better for them to be modular, similar to offerings from Legrand, Schneider Electric, Gewiss, BTcino, Vimar, and others), so as to more easily and feasibly cater for more tastes at once.
Also, in regards to the last kind, going modular will immensely help go towards abiding by more regulations, as Europe has 3 different standards for mounting, with one having 2 mounting options, and will help in expanding to the rest of the world more easily as well.
The standards are as follows:
UK: The boxes and plates are square, with the plates at roughly 86mmx86mm for single gang, roughly 146mmx786mm for double gang (ignoring switch gangs, as the boxes are the same), and for architrave it is roughly 86mmx32mm for single gang and roughly 146mmx32mm for double gang.
There are two parallel screw holes. which I believe can either be on the right and left or on the top and bottom with the length between them being 60.3mm with single gang sockets and from single to triple gang switches (yes, this is confusing to me as well, since we do not use these standards in my country), as well as single gang architrave switches, and 120.6mm for double gang socket and 4/6 gang switches, as well as double gang architrave switches.
China had adopted the UK standards for the dimensions of their boxes and plates, however they expanded upon them to allow for up to 5 socket gangs, I believe (I have no idea regarding switch gangs).
Switzerland: Honestly, I’m still having trouble understanding where to look for information about the Swiss standards for the boxes and plates/frames, so I’ll post this link to Legrand’s Swiss mounting plate with an Arteor frame adapter on their Swiss Catalogue website, as it contains links to PDFs that may be helpful.
Switzerland may be slowly adapting the EU and Italian box standards, however I have no conclusive evidence either way.
Italy: Originally a BTcino innovation based upon Pass&Seymour’s modular switch system, the Italian socket boxes are based upon US socket/outlet boxes, but expanded upon, and completely modularized (also Japan did this, but in a different way).
Firstly, instead of three parallel screwholes on either side, there is only one parallel screw hole on either side, with the distance between them being roughly the same as the two main/closest screwholes in US boxes, with 3-module boxes.
Second, there are 3-, 4-, and 7-module boxes, with 2-, 3-, 4-, 6- and 7- module frames and 1-, 2-, 3-, 4-, 6- and 7- module plates, depending upon the manufacturer, series and requirements (unlike Japan, there is no standard regarding the modules themselves, so modules are not necessarily interchangeable, even between different lineups from the same manufacturer), and some manufacturers also providing 2- and 3- row boxes, frames and plates in accordance to the above as to modules.
The grouping is as follows, 1-, 2-, and 3-module plates with either 2- or 3-module frames (depending upon the lineup, some have 2-module only with 2-module) and 3-module boxes, 4-module with 4-module, and 6- and 7-module plates with either 6- or 7-module frames (again, depending upon the lineup) and 7-module boxes.
There are no limits on frame and plate dimensions, except for the screw positions.
EU boxes, frames and plates exist, but are extremely rare.
Most of Europe: Round boxes, ~55mm/~60mm/~67mm (same internal dimensions, just different parts measured in different countries) for single gang and larger ~70mm (the measurement in my country, I am not sure about others, but again, same internal dimensions) round boxes for junction boxes, with some countries also using UK boxes for some purposes (I have no comprehensive list, but at least France is amongst them), that can either have or not have (the latter is mostly in ancient houses) parallel screw holes that can either be at the sides or top and bottom (or if the electrician has no idea about their purpose, as is often the case in my country, at any direction) with roughly 60mm between them.
There are no standards as to the dimensions of the frames and plates, except for the screw positions.
And there are two methods of installation, the old way, which is required in houses with boxes that lack the screw holes, where claws are held on the back of the frame with screws, and tightened against the sides of the boxes, and the current way, where the screws screw into the box (often coming with the box), you slightly loosen them, guide the frames on them, twist them to the side (the frames have rounded socket groove tracks, with a larger cavity to allow the screw head to go through) and tighten the screws.
Additionally, the newest part of the EU standard adopts (alongside, not replacing the existing standards) elements from the UK (architrave boxes and frames as 1-module) and Italian standards (3 module boxes and frames, and modularization in general, turning the old round boxes into 2-module boxes), and adapting them to the existing standards (namely, the frame installation process), with rounded rectangle boxes of 5-, 8- and 11-modules (2-, 3- and 4-gang, respectively, with 5-gang also existing, but less common, and only using 5x 2-module frames), and accompanying frames (while retaining compatibility with existing 2-module frames) and plates (1-, 2-, 3-, 4-, 5-, 6-, 8-, 10-/11-modules and 2-, 3-, 4- and 5-gangs), and 2- and 3-rows of these also exist (not for 5-gang).
The screwholes in architrave and 3-module boxes remain the same as in their UK and Italian counterparts), but you have the same ease of installation benefits as with the 2-module boxes, on 5+ module boxes the screwholes are only at the top and bottom, so as to retain compatibility with 2-module frames that fit into each others like puzzle pieces, so the 5±module frames have just as many screwhole grooves, but instead of twisting them, you move the frame to the side, all else the same.
The grouping is as follows, 1-module architrave plate and frame with architrave box, 1- and 2-module plates with 2-module frame and 2-module box, 1-, 2-, and 3-module plates with 3-module frame and 3-module box, 4-module plate with 4-module frame (mainly Italian frames compatible with both systems) and 4- and 5-module and 2-gang plates with 5-module frames (the latter plate also with 2x 2-module frames) and 5-module boxes, 6- and 8- module and 3-gang plates with 8-module frames (the latter also with 3x 2-module frames) and 8-module boxes, 10-module and 4-gang plates with 11-module frames (the latter also with 4x 2-module frames) and 11-module boxes, and 5-gang plates with 5x 2-module frames and 5-gang boxes.
The multi-gang plates can also be used with the 2-module frames in separate 2-module boxes that are installed next to each other.
Again, like in Italy, there are no standards as to the modules themselves, so same situation in regards to compatibility, and oddly enough, actual market penetration of modularized systems as opposed to ganged systems, is very slow outside of France.
South Africa, though it uses the same boxes as in the US, have also started adopting modular systems, and also the 8-module boxes and frames.
My country uses both the EU (not yet including the 5+module or architrave boxes, though I plan on changing that, and despite also having everything for the newer screw-based installation method, most electricians are unaware, and install with claws, despite the preferred standards having changed over 50 years ago) and Italian standards (but next to no one is aware that the 7-module boxes are not just for 6-modules, so there are next to no 7-module frames here).
India, I believe, either use UK boxes, with or without the Chinese extensions, EU boxes, or both, though I am not yet sure.
Thailand and the Philippines use US boxes (they are 220~240V, though, despite the sockets officially accepting NEMA 5-15P plugs, with usage of NEMA 1-15P and 5-15P plugs for these voltages being officially standardized in the Philippines).
Brazil, and most of South America, use US boxes (Chile may be using Italian boxes, I am not sure, and the voltages vary, to the point that both ~120V and ~240V can be officially used in the same house, like in Brazil).
I believe that Malaysia uses UK boxes.
I believe Indonesia and South Korea, as well as northern African countries, use EU boxes.
Other countries, I still have yet to learn about.
As for modularization, while I do not know on a per-country basis, I believe that most of the world has adopted to one degree or another (Japan literally standardized almost everything there is to standardize, down to screw torques and module compatibility, which I believe is also the basis to Panasonic’s offerings in Thailand and the Philippines).
Since I am moving in 3-4 months and am determined to make my flat “smart-er”, I´m also up for testing. If you would like to have feedback from a newbie and home automation novice (read- dumbass). Looking forward to it and good luck!
