No, in all honesty I haven’t however I would be really miffed if my employers asked me to do this for such an outrageous reason!!
Why don’t they instead try to negotiate the reno cost w/their contractor.
Why the Nanny?
Do they really think so much more of their home then the person who cares for their precious (+ special needs) children so they can go to work and afford to live in a nice, updated home?
So sorry OP - -
I wouldn’t accept unless they can offer you a benefit or two that would sweeten the pot.
• Use of family washer & dryer for your clothing.
• Monthly gym membership.
• More Paid Time Off (PTO) and/or add’l vacation days.
Etc.
Otherwise, it would entirely up to you.
But it is highly likely that you will have to leave & find another family to work with.
Either way, I am just so sorry they asked this of you.
Unfair, inconsiderate and just plain lacking any tact.