Dear herpers,
I keep all of my animals outside. Most of them in aquaria/terraria, but I have also built an out-door terrarium, where I keep a Salamandra species.
In general, I think for most of the newts/salamanders it is optimal to experince the change of weather/temperature and length of day light to get into breeding mood. In addition an out-door enclosure is the most "nature-close" possibility you can provide the animals including a good hygenic standard.
My out-door enclusre is app 2m-1,2m big and was dig out from the ground (app 20cm). The walls are out of wooden board, which is normally used for bulding houses (Einschalungen) and is kept together by non-rosting angle irons (no problems in decompostion of wood or metal since 12 years). Most important: to the inside a 10cm piece of plastic (transparent) is nailed on the wall, so escape of the animals is not permitted. In addition i added a wide-mesh cover to prevent cats, birds etc to intrude. The interior is starting from the lowest level: sand, forest earth, some big stones (for to go under during frost times), chopped wood and moos. In addition there is a small pool made out of plastic foil. This is a bonus for animals needing a permanent water.
Experince is good, no problems even with Salamandra kept outside at -20° for some days. Breeding is occuring regularly. Feeding animals live inside.
For more information please contact me.
Uwe