Accessible electrical interface
For what it's worth, in the United States, there are a couple problems with that method.  


We have rules on "box fill" or how many wires are allowed in a box.  You have to run the proper numbers, but for a wild guess that's in the neighborhood, think 2 cubic inches per wire.  You might want to consider 120mm boxes since they allow about 40% more splices, but they're harder to get covers for. 





You can't mix high-voltage and low-voltage in the same electrical box or conduit. For instance you see two boxes there, one's for high voltage, the other for low. If you distribute that around the room, you'll need 2 boxes everywhere. 
It is illegal to cover up a junction box with construction work. Your tenant can park furniture in front of it.  But if you need a screwdriver or wrecking bar to get to the box cover - nope!  When you have a blank junction box like this, it tempts the homeowner to want to cover it up. 
The ugly aesthetics of a blank cover can be solved by putting a receptacle there.  For some reason, blank covers offend, but receptacles are dismissed as a necessity.
You probably need a receptacle there anyway, since you must have them at certain intervals.  It's about the war on extension cords; presuming living-space appliances have 6' cords and kitchen appliances have 2' cords.  Many houses are grandfathered; this only applies to new builds and projects large enough to qualify as a "remodel".  I have only spent 2 years of my life in such houses.