4ft X 2ft X 2ft is big enough for 1 dragon only u need to add a foot in depth and length as you add one more so they have plenty of space. if you look on RFUK there are many UK breeders and experts on there as it is more focused on reptiles.

hope this helps

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MY LOT: 3 Cats, 2 siamese, 1 cinnamon oriental. 2 chickens, 1 brahma, 1 cream leg bar. 2 ponies, 1 welsh mountain section A, and a Exmoor/ Dartmoor cross. marine fish tank.
3.2.0 Chuckwallas
1.1.0 desert iggies

http://www.emilysreptilejungle.webs.com/