How to build Summerhouse/Garden Room step by step with estimate costs!

Building a summerhouse garden shed ( garden room ) step by step with costs and estimate spending, in the uk.
From the start of this journey with the base to the end and now finally completed for our gym.

[@DanielCardei]

i`ve done like you near to the fence. the council said its ok but but now after 1 year i found out why they suggest 1m away from the fence.
A weed grew up behind. luckily the neighbours where cool and i had to take down their fence and fix around.
BTW it looks awesome 👍