Re: workshop messing about
Good luck with the project, make sure you have everthing you need to hand before you start ie spare bucket of water etc
I actually built a side flank extn to a 3 bed semi I had.
The idea was to build it onto the back of the garage which was joined with the house. What a project that was. 9ft x 18ft with a fire check door into the garage and a stable door to the outside.
This involved taking down the kitchen chimney- moving the back door so it went into the new extn and replacing the space where the door was with a window. this also stopped a through draught from the front door down the hall into the kitchen
so this is how it went
first getting plans passed. moving back door as mentioned. Digging a metre deep trench 6 inches wider than the breeze block new walls . Cutting earthenware underground waste pipes and re positioning. Mixing concrete for the fondations-building the walls . floor damp proof membrain and laying the floor . Roof joist with furlings for slope having roof professionally sealed with tar etc. every stage had to be passed by the building inspector
That is just a brief outline but I did 98% myself ,apart from the roof and gas fire installation that is.
So I have some idea of what you are tackling and good for you having a go