I think everyone else already said it; the number one thing is make sure you have place with good direct sunlight from the south. If you can get it next to a south-facing wall or other heat-sink so much the better. Where I live in Seattle you don't have to have a greenhouse to grow tomatoes, but you will probably want to cover them in a hoop house or something until July probably. If you don't, you can still get fruit, but it will be in September. Be sure to choose appropriate varieties, in generally anything the seed catalogs claim will riper in 75 days or less is probably a good bet, and Russian heirloom varieties have always done well for me. I once tried to grow Hillbilly tomatoes here; this was a wonderful variety, but I only got a few fruit very late in the season. I suppose a greenhouse would be great if you have the money to spare on it, of course. Seattle is right on the Puget Sound, so cold weather is mitigated, but we have to deal with cool springs and rainy and early summers. Things that grow very well include brassicas (esp. kale and Asian greens such as mizuna), leeks, pole and bush beans, peas, lettuce, strawberries, etc. Cucumbers grow too in the open here too, but they are challenging. I have never had good luck with bell peppers at all, but I know some people who have grown them in a good micro-climate. I have had good luck with winter squash in the past, but one year they were very disappointing, and made practically no female blooms. That year was especially cool. In short, chose your crops and varieties more carefully here, and don't try to grow warm-weather crops without a good sunny area!

@clt3 I'm with you! I love numbers and have always enjoyed working with them...unless it was Trig! Boy did I have a hate on for Trig. Fast forward a few years after High School. There I was in an industry that needed to evaluate WAVE FORMS! Doh! Yah...it's amazing (tongue firmly in cheek) how much we *should know is being taught in....wait for it...SCHOOL! If only we could go back and smack our teenage-selves around a bit. Knock some sense into ourselves. That would have been SUPER helpful!

You need to look at what is allowed by the manufacturer under the particular LVP you plan to use or you may have real issues with the product and zero warranty.

My solution to the cats is a door at the bottom of the stairs with the cats down there. This is partly humor and partly just the truth. We built with a relatively open stairwell and now we have to put the cats outside or sleep is interrupted. For some reason, my wife stresses about them getting cold out there when it is 35 or less. I am understanding for the few nights below 25. But they were born outside and survived as new born kittens although to be fair it was springtime. But their parents did ok. I would build a door at the bottom of the stairs. The cat door would help of course but having to be quiet is really annoying - I'm the early riser. I am a big fan of 2 doors to separate public space from primary bedroom. But you need to decide which side the cats are on unless you leave the bottom open at night and they come down with you.