I used retrofits in standard ICAT cans. They are available in a number of brands. I did run into a problem related to what bus_driver said. I bought 6 LED's at a big box store. A few months later, I went to get the rest (I used 18 in all), and they no longer carried the same ones! I bought another one at a different store, and although they are both the same 'size', the newer one was set deeper, and was brighter than the others. I can see a problem already with various models quickly becoming unavailable, and, given the long life-span of these lights, it will be impossible to match them years down the road. We have 8 cans in the kitchen, so I bought 12 LED's, giving me 4 spares for the future. I have to bring this up- make sure your cans are the right type, and properly detailed when installed. I used ICAT cans, which means Insulation Contact Air Tight. This means that insulation can go right on them in the attic. That being said, they are NOT 'air tight' at all. I built boxes of foam board over them, which I foamed in place to prevent air leaks into the attic. Ceiling cans are notorious energy leakers, and the rising warm air not only costs money, but it can melt snow in spots on the roof, leading to ice damming. Here is picture of a can in my attic. Does that look 'air tight'?

Hi Maureen, sorry for the late response. If you do have a 5" can than I'm afraid none of the Cree CR6 or LR6 products will work, and Cree doesn't make a 5" retrofit product. You could go with the Halo RL7 downlight which sits somewhere between the LR6 and CR6 series from Cree and is designed to fit 5 or 6 inch cans. It puts out more light than the CR6 and has a 3000K color temperature, which is not quite as warm as the 2700K, but I personally like that color temperature more than the 2700K and use it around my house in a couple locations. Most people who have bought the RL7 from us our happy with them so it may be worth a try.

Well, I would be overwhelmed too if I were asked to specify lighting for twenty or so rooms all at once, with no experience or preparation. That's nuts. With 9' and 10' ceilings, you certainly don't need 7" cans. I don't have any experience with 7" cans either, but my guess is that the large cans, paired with wide-open trims and basic florescent or incandescent flood lamps, are a decent choice when you don't know how furniture will be aranged or what the traffic flows will be like; they will throw broad pools of light, so their precise placement is less critical. Larger cans also allow, generally speaking, higher-wattage bulbs, which means fewer fixtures are required, which keeps costs down. Smaller cans are more appropriate when you know just where you want the light to fall. In the bathroom it's good to have the light around the mirror coming from the sides, rather than from above. Sconces are a good choice. Have you thought about pendants or chandeliers in the breakfast area and/or dining room? Do you know how big the table will be, assuming you actually plan to use it as a dining room? You could consider some sort of cove lighting around the tray ceilings. I'm most familiar with kitchen lighting, because I had to figure it out for my own house. The light in kitchens needs to be better than in most rooms, and it's more straightforward to plan because you know where all the furniture and work spaces are. So, just for kicks, here's a suggestion. I'm thinking 5" or 6" cans, with 50W PAR30 narrow floods.

@David Cary: "Will mesh cover the floodlights in the upper corner of my eaves?" Dunno. But you shouldn't have gratuitous flood lights there anyway. "To minimize the harmful effects of light pollution, lighting should Only be on when needed Only light the area that needs it Be no brighter than necessary Minimize blue light emissions Eliminate upward-directed light* *https://www.darksky.org/our-work/lighting/lighting-for-citizens/lighting-basics/