Bearing in mind we don't know whether this is the front, or back of the property, this makes the task harder. It would however seem to be much bigger than it looks because of the additional buildings.
Have you seen this site
http://www.theirhistory.co.uk/70001/info.php?p=9 showing many photos of children's homes throughout the country. The aerial views are interesting to see the size of the homes. I had to keep stopping at some of the photos as many have similarities to ours. I suggest you pour yourself a cup of coffee before starting, it's a big thread.
One thing though, I doubt it's a children's home because of the tennis court, they are more into slides and seesaws.
