My two have a large shed with a concreted run in our garden. I would prefer them to have more but we can't afford anywhere with land. When I was inspected some years ago, I was told that it was fine and I was classed as a 'low risk farm' which made me laugh. My goats are happy and healthy though and rarely ill.
I do know people who keep goats totally in sheds or barns,which apparently is also legal. The first dairy goat farm I visited was like this. It was light and airy but the goats were crammed in (I felt) and never went outside. When I inquired I was told that it would be too difficult to get them in for milking if they were out at pasture. Being a dairy farm, they would have had checks so presumably were considered fine. It made me sad to see them never allowed to go out.