I was mistaken, there are actually two shut offs for the water, and one for the gas, so we ended up putting in suspended gysum board panels, it looks really nice, and doesn't look drastically different from the painted drywall on the other half of the ceiling. I guess they were too far apart just to do an access panel? We also had the Nutone Model #9093WH installed, and I'm so glad we spent more to do that. Even the electrician said it was nice, and I'm sure he's seen it all. We are now in the process of tiling, it's finally starting to look like a bathroom!

I used an external (wall mounted) exhaust fan for my lower level bathroom. You will need about a 4 1/2" hole. I would imagine if you would fasten the rim joist securely on each side of the vent opening it would be OK. I have a spring loaded damper just behind the bathroom grill.

A recommend getting a Panasonic fan. They are very quiet and come in a variety of sizes and features. You should be able to a get a size which only requires a 4 inch vent. The challenge is how to vent to the outside. Do you have a drop ceiling is it sheet rock? The duct will need to run parrel to the ceiling joists. So you will need to determine the direction. Is the a wood frame or brick house? If it is wood framed, I imagine you should be able to make a 4 inch hole above the foundation through the wood frame. It is relatively easy. Breaking through brick or cement is more difficult. It is hard to estimate how expensive it will be.

As for fan-lights in the shower, it seems ineffective to try to remove water vapor laden air from the shower since most of it will condense on the walls before that can happen anyway. My goal is to remove humid air from the vanity area and allow fresh air drawn from the door undercut to reduce fogging of the mirror and window glass. The entire bathroom will eventually dry out if you use a fan with a built in timer and/or constant low speed feature like Panosonic's WhisperGreen series. I have yet to find a fan-light combination that performs as well as separate units. Here are my criteria: no CFL or LED lamps (LED inappropriate in a bathroom; CFL inappropriate in a house) Max sound rating .8 sone max grille size 13x13 flush with ceiling variable speed fan with timer Panasonic makes a recessed spotlight-fan combination (FV08VRL1) but it uses a CFL. I suppose a halogen PAR lamp could be substituted because the CFL is probably only needed to get an EnergyStar rating but I am not comfortable recommending it. To reduce fan noise it is important to reduce back-pressure by using larger metal ducts.