Reassurance please - estimated cost of work

[Howdidthathappen1]

Not really sure what I'm asking for or just need a place to panic!
Moved into a bungalow with existing loft conversion couple of months ago. We new what work needed doing and got a builder friend to do a guesstimate just from pics - hip to gable extension and reconfiguring downstairs involving load bearing walls down so plenty of steel-50k for building so we thought 75k overall with new kitchen/ bathroom.
Architect has drawn up plans and reckons 85k for the building works taking us to 110k. I'm panicking about how we're going to fund this as well as if the house actually warrants that amount - although it is for us to make the house actually work.
I'm 50 and oh is 55 so extending mortgage is nearing the end of being an option.
I think I'm just looking to see if anyone else has been in similar position and its all worked out

where are you based? I have had wildly different quotes from builders. Get at least 3 builder quotes with detailed specifications. See where you can save money. We could have saved over 20k if you go for a more basic design without underfloor heating and standard sized door and windows, etc.
I think 25k for kitchen and bathroom is realistic, as my kitchen alone is about 16k and it is quite big.

Are the architects plans more complicated than what the builder was envisioning?

Architects can be a bit ambitious and want v high quality / expensive finishes or materials, builders a bit ‘bog standard’.

I guess you need to get quotes and ask your architect to adjust, or else give your architect your budget (holding a secret contingency)

Our builder reckoned he had under estimated the steels needed until some of it was on the architect drawings - in fairness he couldn't view first hand until after we bought due to covid - so it's no ones fault but ours really for going with the 75k we thought it would be.
Just feeling a bit shell shocked and wondering how many hours I can physically work to try and make up some of the extra - not going to dent 25k though!
Unfortunately not doing the work isn't really an option as the house is seriously 'quirky and sat on the market for ages - we got it for a good ish price but all relative to our budget

No ‘value engineering’ you can do?

Ask your architect.

Does it have to be hip to gable?

Would a really big dormer work?

Get a quote / ideas from a specialist loft company?

Also bear on mind that the cost of building is currently skyrocketing at the moment. Materials are all more expensive, there are massive supply chain issues and labour is hard to come by.