1950 was before my time, but I think the smell would have been the biggest giveaway; perhaps it's just as well that the photo cannot reproduce it. I think I can spot the definitive clue - but in the best traditions of Kermode and Mayo I won't reveal the spoiler.
I remember the House, my first visit to Chester would have been around 1964/5 and there were a number of Grevy zebras and the two zebroids in it.(common zebra weren't in this house, were they) But what are those net-like things above the public barrier?
Surely this is a recent pic? Can't decide what I think about it not changing in 65 years.... Part of me loves the indoor 'cattle house' for how close you get to the tapirs and the smell. Apart form the giraffes and elephants it's the only place you can go inside and smell an animal! The other part of me hates how tired and old fashioned it is..... If I was a betting man I would not be sure it will be around for much longer
Ironically, I didn't expect this to turn into a quiz or I'd have waited long enough to get the Congo buffalo out of the shot! The EXIF gives it away a bit too.
It was intended more as comment on the age and style of the building.
The EXIF data is pretty conclusive: perhaps SMR could forge the date and time, but the GPS data clinched it for me. I spotted one more clue that hasn't been mentioned yet: in 1950, the gates between the indoor stalls would all have had to be closed because of the number of species kept in the house.
I expect that it will have to go quite soon. I don't think English Heritage will be listing it
Stop fighting zoochatters, or I'll have no option but to make you sit on the naughty step (Between the Coronation Hall and the Milk Bar!)
Here's a scan of a 1950s Chester Zoo Postcard showing the Zebra House as it once was when it contained Zebras and Zebroids. Health & Safety regs permitted a meer hint of a stand off fence.