Shape of things to come?

[Spoon]

Hi, I live in Derbyshire in the UK and I'm planning to build my first WFO in Spring this year. Although we have a decent size garden it is situated on quite a steep bank and therefore split into several smaller terraced areas. Herein lies my problem, I'm mindful that once finished the oven will take up too much room and I'm worried that I might not have anywhere suitable to site the oven. We do have a small court yard area behind the house that has existing retaining walls and I was thinking about building a WFO in one corner in the shape of an eighth of a sphere together with the normal front landing. I'm not sure how I would construct this shape or how strong it would be but I would be interested to hear from anyone who might be able to point out any problems I might have. Thanks.

[JRPizza]

Spoon, welcome to the forum. One of my road bikes is a Mercian, so I've never been to Derbyshire but my bike has.