
There is nothing to say though that there will be two litters of pups a year,a dn if you contact the tax office on two litters if they claim the expenses involved they would more than likely not earn enough for tax purposes, especially if one or both don't work.
It may not be the way many of us would choose to breed (though many people do and there is nothing wrong with outside kennel facilities, the dogs are happy if they are clean well fed and have some stimulation. The latter is the main thing lacking from a welfare point of view, but plenty of the nations Pet dogs are the same rarely getting walked etc, and I don't see lots of prosecutions under the Animal Welfare Act.
Your only real issue can be excessive noise, (prolonged periods of barking and at antisocial hours) as you say they keep things clean.
I am in a city, with 25 x 60 foot garden, 5 adult dogs and breed a litter on average once a e, though there have been two occasions where I have had two close together and then nothing for 18 months or more).
My pups start going outside at about a month old and potentially will be spending a lot of their time outside for month to two (depending on when they get homed). I have 3 here at present coming up for 11 weeks (one my own and two others going in a few days).
My next door neighbour had a 'word' with me a few weeks back when the noise of them playing when let out first thing (which unfortunately with pups is as early as 5-6am, screaming to go out to be clean) was disturbing them as due to the weather they Had their bedroom windows open, pups can be noisy playing tag etc, even if they drop after about 15 minutes.
This means I now keep them in (screaming or not) until 8am, and was able to confirm that the noise of this did not travel to them from the kitchen where the puppy pen is.
Because of living in a city suburb with close neighbours, even though I have a double kennel and run (useful when pups are small enough to get through any crack), some of my dogs only use it as a bedroom, and my dogs are never left outdoors when I am not home, though the backdoor is left open when I am in when weather is good and everyone is quiet.
Any barking (neighbours teasing cat etc) and they are take straight indoors, if I go out they are confined to the kitchen with radio on, to minimise outside stimulus, hence inclination to bark.