Insulating loft strange void to tackle but how?

[mark.allheart]

Im currently in the process of reinsulating our loft and I've come across this void while tearing out the old insulation. It was completely stuffed with insulation. The loft was boarded over with only 100mm of insulation. So im tearing out the boards and the old insulation and plan to replace insulation to a depth of 270mm and not reboard it. Im starting to think I should have just laid it over the floor boarding but surely that would have been less efficient thermally?

Below it is the top of a cupboard build between the bedrooms over the stairs. The house is 1900's so im assuming this isnt the first time people have come across this.

Im just trying to figure out what the best way to go will be when it come to laying the insulation back in the loft.

Just lay boards over the hole and insulate as if it wasn't there or should I insulate down at the bottom of the hole and up the sides?

Any ideas would be very welcome

 

[Wayners]

Maybe a dumbwaiter was installed there 100 years ago?
Line inside with sheet insulation maybe.
Place a board over insulation at the bottom to step in. Leave open for safety and lay insulation around opening.
You could draw a rough plan on cable locations before you add insulation.

I wouldn't not lay insulation on loft boards. Needs to be tight to ceilings

 

[mark.allheart]

It's a cupboard built over the stairs. A bulk head of sorts i suppose but it isnt full height of the room and I suppose rather than "waste" materials taking the ceiling all the way across they just left the gap as considered the top to the cupboard ceiling enough.

However for my purposes its not that helpful. I think later on I might extend the height of the cupboard and plaster board it to put a proper ceiling in there but for now its a very strange area.

Lining it with sheet insulation could work. I guess i was hoping sealing it shut from above and pretending it wasn't there would be easier. But probably not right