bearded dragon enclosure.

Question
have a juvenile bearded dragon, in 20 gallon aquarium, will need upgrade soon. was told since i do not heat with central heat and air that a wooden enclosure would be better. was told that it could be made with melamine or particle board.   went to lowes, bought the particle board, got it put together, then seen online, not to use particle board.  if i did, to seal with polyurethane inside. then read no sealing. he is growing, eating good, so need that to continue. was also was told since he was used to glass, he would be better off to remain being housed in glass. need an solid expert to clear this up once and for all. am  thinking about getting a desert terrarium habitat at petco maybe. longest is 36 long, not long enough i know. but options are limited. what  is right?

Answer
I have to wonder where you're going to get all this advice, because much of it sounds ridiculous.

First, if you're going to have an enclosure in an unheated area, insulating it is a good idea - you may also need a supplemental or night time heat source may be needed to keep the cage ambient temperatures correct.  Particle board isn't a fantastic choice for a reptile cage.  If you're going to use it, yes, you must seal it:  Here's why:
Particle board is made of wood chips pressed together and adhered using glue.  This glue often contains toxic chemicals such as formaldehyde, which will outgas when the wood is heated (As it will be, if you're using it for a reptile cage).  Additionally, particle board swells and malforms, and may mold, if it becomes wet.
This is why a waterproof sealer is needed.

As for what the dragon is used to... that's the most ridiculous thing I've ever heard.  Bearded dragons are quite intelligent reptiles, and he'll adapt to new surroundings, lol.

What's important for a bearded dragon are adequate space, correct temperatures (air temperature on the cool end should be 80F - under the basking light, should be 110F), and proper diet (a mixed salad of nutritious greens every day, and gut-loaded, calcium-dusted insects.  Younger dragons need to be fed more often), and strong UVB light.

Adult beardies need enclosures around 4 foot X 2 foot X 2 foot.  There's really no point in getting anything smaller for him, since they reach full growth in a mere 18 months.

I'll link you to some care sheets which are actually authoritative:  
http://www.carolinaclassicdragons.com/bearded-dragons/bearded-dragon-care (Note- if you take your dragon outside, use a secure reptile harness, or keep them in a wire carry cage - they will be gone in a flash, otherwise!)

This is more like a list of quick notes:  http://www.rainbowbeardeddragons.com/caringforyournewdragon.htm

http://www.southtexasdragons.com/care-sheet.html (An excellent sheet with detailed information)