Coop design to prevent bugs

[Labsandchickens8]

Hi all,
I am a new chicken owner who is currently designing two chicken coops. I have 3 older pullets in a large secure run with a cheesy coop my son bought from Amazon. And 7 8 week old pullets in a secure annex currently in a large dog crate with roost bars added. I clean the shavings out and replace every day or two.
I would live to buy an Eglu cube for the younger ones for ease of cleaning. Husband says no because of the expense. Their situation is temporary until husband builds permanent coop and run. It will be then used for hospital or isolation purposes.
He is going to build them a quick wooden coop, 4 by 4, elevated off the ground with double doors for cleaning. How can I make it as bug proof as possible? Painting the inside and maybe lining the bottom and sides with linoleum? Or plastic panels?
Your thoughts are greatly appreciated.

 

[DobieLover]

I've had my birds in painted wood coops for 6 1/2 years and I've never had a problem with mites. I did have one minor incident with lice but with one treatment they were gone because I caught it early.
A 4x4 coop is big enough for 4 birds.
If you have a large attached predator proof run with a solid roof on it where you can leave the pop door open you can probably get away with a 4x8 coop for 11 birds but nothing smaller.

 

[nuthatched]

Build and paint, eglus area a horrible rip off.