Thanks everyone - I heard back from our friend today. The tenants have been given notice on their rental agreement: apparently when the managing agents went in, they counted 21 beds (it's a 4 bed house!). That said, apparently it had been kept "immaculately" .
Thank you for confirming we needed to say something.
If it's your friends' house say something to them... They may know what's going on but they may not, wouldn't hurt to mention it. Sounds like the managing agents aren't doing a great job at the least to be honest.
Sorry, I should have pointed out that we suspect the house is being used as a kind of student boarding house for short-term stays.
There are notice boards on display in the hall (I can't read the language and only get a fleeting glimpse every now and again when we pass - the front door is often left open) but they look like a list of house rules (bullet points seem universal!).
God, I sound like a ridiculously nosy neighbour, but just concerned for the home our previous neighbours looked after so carefully (& ultimately will want to sell at some point).
Our lovely neighbours of ten years moved out of their home (next door) about 9mths ago. They had been trying to sell their v nice house for a year but didn't have any luck so decided to rent it out instead. The first prospective tenants fell through before signing contracts and after the house being empty for 4mths they eventually managed to let it out to two couples studying here from overseas.
We were really pleased a) for our previous neighbours - they'd stretched themselves to move out to their dream home in the country - and b) for us, as there was finally someone next door again!
The new neighbours seem nice enough; but we've started to notice some odd goings on: our house numbers are the same bar one letter (akin to flat numbering although it's a row terraced house) and we've been getting people now knocking on our door at random times of night (10/11pm usually) asking in broken English for our new neighbours. Forgivable a few times but now happening once a week at least. There are often large groups of suitcases waiting on the pavement outside their people carrier, seemingly belonging to lots of different people.
There have been several large pieces of broken furniture (mirrors, doors, car seats) left outside the front door for days on end, despite us explaining (when asked and in a friendly way!) which days rubbish gets collected and how to contact the council for bulky waste collections. Again prob not a problem in itself but our front gardens are adjoining without a fence and I don't want my toddler injuring herself on broken glass fragments in the garden. Finally, today we spotted a set of large bunk beds through their upstairs window: there are no children staying there.. Our previous neighbours spent a lot of time and money renovating their home (much more house proud than we are!) over several years and we're still in touch with them as friends a fair bit (our children are similar ages, we've been to visit, they've come back for playdates to us) and we kept an eye on their home while it was empty.
Given how long it took them to find tenants, should we say anything to them? If so, what? Should we say something to the managing agents instead? Is it even any of our business?!! Thanks for reading this far..