I hate to crush your enthusiasm but I can see nothing but difficulties with this idea. Even outdoors getting four solid green walls is a tall order.

Things to consider:

Light: Even ivy needs light and unless your room has a glass roof there is unlikely to be enough light for plants on every wall.

Growing medium and containers. To have ivy over every wall you would need pots or troughs all around the room.

Access: If you have trellis 1 inch away from every wall how will you access power sockets, light switches, etc? How will you clean/redecorate the walls?

Dirt: Indoor plants do not get rained on so somehow you will have to get the dust off your plants without damaging the wall beneath. Free standing or hanging plants can be rinsed off in the shower but yours will be permanently stuck to the walls.

Aerial roots: Ivy is a self clinging vine. It will not stay on the trellis but will try to stick to the wall.

Time: to achieve this effect would take several years providing all else went well.

I have seen this done on internal courtyards (no roof.) But only with undecorated walls to which the ivy sticks by itself and in a milieu where hosing it down periodically to clean the leaves does no harm.

If you go on over to the Houseplant Forum you can ask some of the regulars to post pictures of their rooms. Some of them live in mini jungles. But the plants are not fixed to the walls.

Here is a link that might be useful: Houseplant forum

Don't worry about crushing my hopes. If it can't be realistically done, then thats information I need to have. Thx for your inputs. :) Does anyone else have any thoughts?

Get some grow lights off ebay. u can use several planters or one long one. i have several different types of ivy vines growing in water beads only no soil. one likes it better than all so far. i think its an arrow head. not sure it was given to me. i think u can grow several types of vines in them. if u can root in water u can usually grow it in water beads. it would make it interesting