I live in VA and my workshop is an unheated, uninsulated garage. I work out there year round, even when temps are below freezing. I can't say it's comfortable in the winter (or when it's 100 degrees with 95% humidity) but I haven't had any major issues. I have had some big box green wood warp on me after I built a couple bookshelves and brought them into the house, but that was more a factor of the green wood than my "shop".
Evidence of a removed fireplace makes it clear that the woodworkers were doing tasks that required warmth, like using glue. The type of glue used during that time had to be heated to a certain temperature. Bill Flynt, a former colleague of Garrison, tested the wood of the shop and found that it is second- or third-generation wood, meaning that New Englanders had already cut down and replanted lots of trees by that time.
What is the one thing every woodworker needs? Yes, a workbench. Now that you have or at least I am assuming you have worked on so many woodworking projects, you are close to becoming a professional woodworker. You now probably owe yourself a nice woodworking bench. You should also know that a true woodworker never buys his bench from the market, but always builds one himself. But before you start this project, you should know what a workbench is.
My first shop was a 8 x 10 ft room, actually a bedroom, with 10 ft high ceilings in a older home in Chicago. I had a 10" Craftsman TS, drill press, 8 1/4" Skil saw which still works, some welding tanks, hand tools and... my bed was a loft across the 10 ft length 4 ft down from the ceiling with a ladder against the wall to get up. I was 16 yrs old then, now I am 66 yrs, have 2 shops with Craftsman power tools up stairs, and Grizzly tools ,a Powermatic 68, a MIG welder, and other tools on the ground floor. I've come a long way, You think? I remember making bases for sculptures called "plinths", my first commission, in the living room, 5 pieces rather large, several ft long and wide. The house was haunted, and my mom told the "spirit" to leave and go back downstairs. There was a cold draft and the straw chair would rustle with no one sitting in it. Wow, does that bring back memories from the '60's.
Mine is similar but a bit more robust. The top is a sandwich, two 18mm sheets of WBP ply with an 18mm mdf filling. The legs are mortise and tenoned together, the ends glued and pegged, the stretchers are joined with long bolts so it comes apart. I stiffened it by adding a very closely fitted cabinet underneath (it had to go in dead square) and it is now absolutely rock solid.
After I left the magazine for a new job, I did all of my woodworking in my small two-car garage, but it was a struggle. Power, lighting, and temperature control were limited. And because I shared space with our cars I was always moving machines around, often while in the middle of a project. On top of that, my tool and machine collection had long since eclipsed the space. For all these reasons, fixing up the garage wasn’t an option. My finished basement is a family room, so it was out, too. An addition to the home or a stand-alone building would have been too expensive. I had to find a better path to a shop.