I have found one rather interesting addition - in 'Captive Habitats', a book about building reptile enclosures by Beat Akeret that I got for Christmas, there is a description and photograph of an outdoor enclosure for red tegus (Salvator rufescens) at the Alligator Bay Reptile Zoo in Mont Saint Michel, France. What really sets this exhibit apart is that the lizards live outdoors all year round.
While it doesn't relate to a zoo, the author also includes an interesting account of keeping desert horned lizards, Phrynosoma platyrhinos, in an outdoor enclosure. While they lived outside year-round, in the winter the enclosure was draped in bubble wrap and a heating cable was snaked through the cacti. They lived for many years in this exhibit but never bred. Western banded geckos, Coleonyx variegatus, trialled in the same enclosure were removed because they emerged from their winter hibernation too early.