Thank you Cotton
Yes he is our first Robo. The first attempt at a set up was "technical" - along the lines of what I read was good for a robo. The second one was based on the cage and access and basically as long as he has a shelf, a wheel and plenty of substrate he was happy. He ignored houses and used to burrow under the Fitch. Until I got him the labyrinth house which is dark inside and mimics a burrow with rooms - he loved that and moved straight in. But he doesn't like you taking the roof off - so he keeps two burrows and moves out of the house if disturbed. Then moves back in again if I disturb the other one.
If I get another robo I will try harder at taming initially!