@Tanya534 Go through your local historic newspaper archives and find the images when it was technically a home back in the earlier years and they didn't have such legal requirements.
Find the relevant legislation of the era and throw the book at them.
I smile each and every time I see 'Tiny House, cabin and the likes' because those sized homes were oft once a livable home for those of days gone by.
Try also sourcing info to get it registered as an Historic Place.
Some may not realise old barns also were once someone's home, and not only that for animals, hay or farm tools.
All the best
Central To All, Home and Location, Remuera, Auckland, New Zealand