EE was longterm landlady by marriage and janitor of an appartment block as well. ......so I allow myself to part with some of my wisdom
Got a bit of bad news for you. You have done the right thing and asked the rental agency/landlord whether you could install a washing machine.
Alas they have told you NO. So if you go ahead and install one anyway you are in breach of their rules and this can lead to you getting kicked out.
Sometimes this specific kind of problem, is regulated in a Paper called HAUSORDNUNG/ RÉGELEMENT DE MAISON, which lists the do's and don'ts in an appartment building, and which gets handed to you together with the rental contract, Sometimes stuff like that is also regulated in the contract itself.
But, in the end it really is the landlord or the agency who's got the last word in a case like this, and their say-so is the law.
A washing machine makes quite a bit of noise and is capable of making floors and walls reverberate, especially during the spinning circle. This is also very disturbing to neighbours, we are currently having a big fat bother with a downstairs tenant who did install a WM without asking.....and in our appt. block it is not allowed too.
I have the pleasure to get woken up between 2 and 4am by my bed reverberating, because they run the machine during night time.
This reverberating can also cause damage to floors and walls, the noise is another problem,possible breakages and water spills are also a risk, then on to hang the damp washing inside a flat is with the incredibly insulated houses of nowadays a great risk of developing mould, to name but a few problems that could ensue.
If you go ahead , and neighbours complain about the noise etc from that WM...you may most certainly get a letter of a kind of warning to uninstall this machine immediately. If you don't, they have the right to terminate the lease within a very short time.
Is it really worth all the bother that this could ensue?? Isn't there another way within your appt. block to see if you could do swapsies of your day/slot with a neighbour or some such thing??
HTH
EE