I guess the "knobs" are the valves? No heater/no spa? If it's a pool only, not often. The easier access the better though.

The dimensions are approx. 20 X 20, including the bathroom. A majority of the dimensions were decided for us, as we are adding on to the back of the house, and the foundation and topography determined much of what we could do. My plan is for it to be all enclosed with a sliding door to the outside, and a bar-type window (so we can put bar stools outside). The interior, again is mainly determined by the existing situation. In the end, we plan for it to have a full bath, a bar set up with some cooking/washing capabilities, and room for some furniture. I wish I could say I have it all planned out, but my husband is doing most of the work (saving big $$) and we are doing the pool first, with this prepped but we are not actually building it, now. I know it is unconventional to do it this way, but that is how we tend to work. He is the do-er, and we design together based on him telling me what needs to be where for logistical reasons and me telling him how I want it to look given the logistical constraints. :)

I have an overflow drain, but at the moment it's installed just below the coping near one of the skimmers. It's a small overflow with an opining of about 1/2 inch... and the whole opening is above the top level of the skimmer so it's not going to work very well. It just feels like I need to change the elevation of the coping somehow to make an accommodation for a lower waterline.

Hi fins up I'm in CT where the normal season is early May w/ a heater until early Oct. We just installed a vinyl 20X38 basic rectangle and will be building a retractable enclosure like tresw mentioned. In fact, the link he gave you is for an outfit here in CT right around the corner from me. We couldn't use them, though, due to their narrow span. They'll only go to 29' and we wanted wider. Ours will be 34'X54' and was manufactured by a company in Canada. The typical price is approx $55/sq foot installed. I know they have sold a number of units in Michigan; in fact I spoke w/ a customer of theirs when we first started looking just to get a neutral opinion. They LOVE it! Feel free to email me for more info if you'd like.; I'm at soccerfans6@yahoo.com. It's a big investment but we figured we won't be able to retire until we're dead so we might as well enjoy as much life as we can now!! Who knows; maybe we can rent it out for weddings, birthdays, ect and help pay it off sooner! Good luck w/ your decision! joanneswimsct