Just though I would show some pics of our Australia Wide room extension called the captains quarters. It replaces the side wall completely for installation.
A few have said that it is a pain to put up due to the pole system, agreed it was for the first time but it really isn't that bad. It basically has a frame that holds it up, the frame can be set up smaller than what is needed and placed inside the annex and "stretched out" to lift and hold the annex around it. We bought it for the 4 bikes and four scooters but it also fits the table in there. A bed will fit in there also and it can be closed off from the main annex with a door. It adds another 2 metres to the annex so for extended stays it will be useful. I wont use it all the time but handy to have for many reasons.