I think it would be pretty awesome if there could be a portal to your house somewhere between Varrok and Grand Exchange. That way while building or if you are usually in that area you don't have to travel all over the place to bring materials to build or grab something from your home. Also, another idea. Maybe there could be a way to have an option to leave certain doors closed and others opened.
I personally think that area is a little too cluttered at the moment - what with the clue scroll area and cosmetics store. I wouldn't be against a portal in Varrock, but it should come with a more wider Varrock rework, rather than a stand alone update.
That said, I don't see the need for it to be so close to the GE. A lot of the current house locations are a short run from lodestones/existing teleport locations and as stated, house tabs exist.