Absolutely worth having one. I had a garden on three levels in North Yorkshire. So,the first thing was that I chose the company who made sturdy ones, and was actually able to choose how the windows would be put in and the size. Mine had a small long window in the rear and then two large square windows in each side and then the french window style doors could be shut or opened to suit. That meant that it was brilliant for many things. On those clear but cold days I could sit down there with the doors closed and it would be warm and comfortable in there, with a great view of the garden but dry. We got a simple walki talki to use between the house and the summerhouse. Kept fold up chairs and a table which could be used inside or outside . It was set on the lowest level of the garden, close to the pond and near a shed, which is where I had gardening tools and pots and the lawnmower etc etc. I happily spent ages in there on cold or wet days doing all sorts, repotting plants, sowing seeds etc. Used to keep my older encyclopedia down there to be able to check up anything I wanted. Any roadworks or work being done in the vicinity, we would take our lunch down to the summerhouse and I had my radio so could listen to radio 3 and of course gardeners world down there. I have taken part in the birdwatching and counting many years, but one year it was so cold that I actually did it from inside the summerhouse. Good friends knew where I would be if no sign of life in the house and would come round the back, and I didnt miss annoying phone calls or unwanted knocks at the door. We enjoyed using it for many things, a base for welcoming friends and neighbours to a drink . A good plant swap basis with the chance for people to wander across to the borders to check out the plant A place to sit and think , somewhere that you didnt look round and see jobs needing to be done. Dont want to watch football? Had a bit of a row with someone? Dont care for the friend of another family member coming round? A brilliant reason to disappear down to the summerhouse, muttering plants to be watered or whatever.
Oh, it was so lovely and it gave us a lot of pleasure and peace and quiet. After my husband died it was also a great special place for me , and it is something I miss very much since I had to move. It was also mentioned by the buyers as a reason they wanted the house!! They were keen gardeners and that was a major thing that appealed to them. Just one word of warning! Make sure that you claim the space and welcome visitors, or you might find that it will be taken over as your husband finds many reasons to use it too. Enjoy it. Oh of course you can also grow things that dont like to be out in the cold. I would get a notebook already , so that you can start by keeping a note of seeds and plants and if you see a plant you like you can have a check up if it would grow in your area. Oh I envy you starting with a new place to enjoy. Good Luck