there's nobody here but us chickens

Don't forget that your garden will become a prime target for every urban fox within a couple of kilometres radius - and there will be a lot more of them than you might imagine.

I actually own a house that has a covenant specifically prohibiting keeping animals in the garden, including chickens. As said, unless you take measures to protect them, you WILL get up one morning to find them all dead.

I think the rooster is a none starter presuming you have any respect for the neighbours.

The person who can tell you about the legalities is the notaire/notaris who handled your purchase of the apartment. Ask him/her.

Hi, first thing to say is I love chucks and have flock. However you state you are lazy and Im sorry to say hens actially a lot of work. They require the following.
Warm housing that you shut EVERY night and OPEN Early EVERY morning. Now you can buy a timer to do this but that's more money. Hen houses aren't a few quid a good one will cost you quite a few hundred euros. You can maybe build one but it will still cost in lumber.
This housing must be is regularly cleaned, by that I mean like every week, it usually needs disinfecting and scrubbing or jet washing.
You then have to dispose of the droppings, as they roost they mostly poop do at night. Shovelling out hen coops can be really smelly in the summer. You can't leave it as it attracts flies. Also the ammonia is unhealthy for the birds. Wooden housing will need treatment for red spider mites regularly to keep your birds healthy. If you garden not an issue throw it in the compost if not Hurm what to do with all that manure?
Then you have to offer fresh water every day especially in hot days.
Food daily again yes they do forage but they need more than that.
So even if your hen house has a timer you need a hen feeder who can come in should you want a more than a weekend away.
You then have to stop rats and mice from coming in to eat the left over hen good. Still thinking they are a simple solution?
They need shelter from the elements in addition to their home. So maybe that's bushes maybe it something you have to build. They don't like it very hot or very cold. They need shade and shelter from the rain.
Hens also like a dirt bath and they will dig holes to do this and they will grub up plants and bushes alike. If you keep them in an enclosed area the grass will vanish fast and they will have smelly pooped earth in that region and get really bored. If you leave them free you risk attack by cats dog or foxes plus they will eat any plant they like the taste of.
This means when you leave you will have to pay get the garden back into a reasonable state. Reseed the grass, put in bushes etc.
Some hens like the Marron lay pretty much each day. That means one hen seven eggs a week, two hens fourteen etc. We gift away quite a lot some times. We have three boys and we still don't eat all the eggs five hens produce.
Then they have fallow weeks at certain times and this means that they go off lay so your doing all this work and maybe one egg a week. That can last a month maybe longer.
Roosters can be aggressive good to keep foxes out but noisy. We are rural our neighbours don't mind our guy crowing at first light. However imagine that four am in a residential street. Ours has come to an understand that we don't pick up his girls he doesn't attack us with his Spurs, they use cockerels for fighting for a reason.
Laying hens don't tend to be good cooking, meat chickens are a different breed..
Culling hens is quite a hard thing to do taking. Live bird and breaking its neck isn't pleasant. Especially if you've been caring for them. Then you need to pluck and gut them. We don't keep meat chickens for this reason.
So now I've put all this in are you still feeling it's a lazy option?

I was not accusing you of being a bad neighbour, just pointing out that you may well be if you get a rooster. In the summer they don't wait for 4AM.

Btw you don't require a cockerel for eggs hens just lay. I'd suggest you check out.
http://www.backyardchickens.com
Before you build anything lots of advice here

Also if you are feeling lazy and don't mind forking out for quality I'd highly recommend green frog hen houses, they will ship here, easy to assemble made from recycled plastic quick to jet wash. Just google them