Ideas Needed!

Nearly a year ago I agreed to make new slipcovers for the local family drop-in. As loosely arranged things go, it took a LOOOOOOONG time to get to the point of actually sewing something. I am very near that point. The fabric has been purchased and pre-washed (both by me and by the cleaners as my machine wasn't too fond of 7 meters of home dec weight cotton).

The only thing is that I can't come up with anything much better than what they already have. The cover has to be easily removed for washing at least twice a week. The covers they currently (see above photo) have used velcro-style fasteners, but those tangled around the fabric during the wash and so had to be cut off.


My thought is to make something in a similar style, but run a heavy duty industrial zipper along the length of the couch. But should I make essentially two zippered sleeves? One for the couch back and one for the couch seat? Or would it be possible to make one "sleeve", but with two zippers at the meeting of the seat and the back (in cross-section, it would look a bit like a scrunched capital B).

I am kind of leaning toward the two sleeves idea as this seems easier. Did I mention that there are two couches to cover? They are different sizes, but identical construction.

Any help or advice you have on this topic (about the actual construction - not about agreeing to do things that turn out to be difficult/uninspiring) would be greatly appreciated.