The bathroom is an appendage onto the Bedroom Dome, accessed via an interior door.  As such, it can ‘lean' it’s weight onto the bigger dome.  The plan is to make use of the flexibility this provides, but still craft a safe dome.  Based on learnings from the building of the Windscoop, which was a ‘free style’ build, where we used the ‘lancet arch’ math measurement concept, but were flexible - and it worked.  

The goal here is to use 14” bags to build up 3 feet to the springline.  From there, we will slowly reduce the diameter line from 120” (5 feet, what the radius ring will remain from the ‘center pont’) to 96” inches to build up an 8 feet dome by the time we get to ~ the 18-20th ring of bags. 

What we tried (going from a 10-8 fooot dome during the last 65-80% of the dome build) and why: The lower portion of the dome will be ‘fatter’ and then it will narrow faster than normal as it rises, to close as an 8 foot dome.  

The hope is that this will make for a more useful (ie 'higher’) space for showering, but not climb (or require the materials) to the height of a 10 foot dome to achieve it.  

WIth a 2 foot buttress aound the base, and the bigger bedroom to ‘lean onto’, I am hoping the structure can support the plan.

 *update Dec 8, 2022 - it doesn’t work!  Going from a 10’ to 8’ dome just doesn’t work - the closure would happen too soon at the ~ 80% mark we started to close with a shorter radial of ~ an inch each row.  We slowed it down (a bit shorter diameter line each 2-3 rows) and closed with a 9’ 2” dome diameter length - a bit faster than would have occured with a 10’ dome,  but not too radical.  It worked.