Bigger viv for my red foot

[Tort bruddah]

Hello I was just looking for some help on upgrading my torts vivarium they are getting to 5 years now and starting to look like they need a bigger viv currently they are in a 4 foot viv but I don't know what size of vive to get next or what size of uvb strip light any help would be appreciated thank you

 

[ZEROPILOT]

"They"?
You have more than one sub adult RF in a 4' vivarium?
You need to go substantially larger. And what type of UVB light do you have now? It might still be sufficient

 

[Tort bruddah]

"They"?
You have more than one sub adult RF in a 4' vivarium?
You need to go substantially larger. And what type of UVB light do you have now? It might still be sufficient

Sorry I meant they as I'm still not 100% sure on the gender I only have 1 red foot the uvb is a 12% 350mm strip light and a basking light at the other end of the vivarium

 

[ZEROPILOT]

Sorry I meant they as I'm still not 100% sure on the gender I only have 1 red foot the uvb is a 12% 350mm strip light and a basking light at the other end of the vivarium

Redfoot are pretty simple as far as the need for UVB. The source doesn't need to be super powerful and the tortoise only needs a few hours of exposure to it.
Your 12% is a really good tube. So you probably do not need to replace it.
It should be about 20" away from your RFs shell. But he doesn't need to be directly underneath it to get what he requires for good health. So if the enclosure is wider or longer. Or both (Hopefully) you can still utilize that same tube.
You will probably need additional heating sources to keep the ambient air temperature up between 80 and 86°. But depending on the type of closed chamber you design or decide on, that may or may not be necessary.
I once had a small CLOSED CHAMBER enclosure inside my home. With the entire house temperature of 74 the enclosure stayed pegged at 82 during the day with only the tiny bit of heat transmitted from my UVB fixture. (That was an old school T8 unit)
So, all closed chamber enclosures have different requirements