I'm not sure if this goes here or DIY or somewhere else but this seems the most likely.

As our collection grows and our need for feeders continues to grow we are continually adding more and more breeding racks to meet the feeder demand. This is starting to take up a pretty good chunk of space in our basement and the smell is a constant battle. We currently run 30+ tubs of rats, mice, and ASFs and by next summer to fall we are planning to up that to around 70 tubs give or take.

In order to free up space in the basement and to alleviate smell issues we are planning to build an out building and insulate it so it can be climate controlled. Here's my plans so far...

The building will be either 8' x 16' or 10' x 16' with a standard roof not a barn style or storage shed style roof. The reason for that style of roof is it will allow for more vertical wall height without a lot of wasted ceiling area inside that would waste heat. I plan to use a window air conditioner with a thermostat to keep the air temp at 75 in the hotter months. I'm unsure as to what type of heater to use. I had a couple thoughts, first I thought just an electric oil filled heater as it will only be a small area and second was a propane garage heater and get a propane tank similar to what a mobile home uses to fuel it.

Im planning to use the styrofoam insulation panels between the wall studs and Fiberglas rolled insulation over top of that then 1/2" plywood for the interior walls.

The questions I have are 1. Does anyone have experience with the garage style heaters and which would be a more cost effective way to heat? 2. Any ideas to insulate that would work better than what I have planned? 3. Any general flaws that anyone can see with my plans? 4. Does 8' wide seem wide enough or should I go 10'? The racks will be approximately 28" deep and there will be one row on each side of the building so with those measurements I would have about a 3' 4" walkway between the racks. That seems a little snug but if I could make it work it would mean heating and cooling that much less square footage. Lastly, what temps do you think would be acceptable? I'm thinking heat to 60 and cool to 75.

Any opinions you guys have would be great. Thanks guys.