Bythesea-
As long as the ramp is on your property, you do not have to adhere to thosr specs.
Those numbers (1ft. of ramp per 1in. of height) are for commercial properties to accomodate all levels of disability, i.e. people in w/c , using walkers, canes etc. I know contractors who do ADA work say that- we had one guy who wanted to put a 12ft. ramp in our family room! We didn't use him!
A power w/c can navigate a slightly steeper incline; but if you are using a walker or cane, or even if someone is pushing a manual w/c you can't go as steep.
Not sure where you are now- w/c?
We have a 10ft. ramp for a 16in. rise (2 steps) in the garage, an 8ft. ramp for a 12in.
rise inside in our family room, and a 7ft. ramp for 12in. rise going out to the patio. It depends what incline you are comfortable with.
We did a test with a portable ramp for the family room- tried a 6ft. ramp for 12in. rise.
It was a little steep for my husband; unlike Al aka "Evil Knevil" who told me it would be OK. LOL A power w/c can handle it, it depends on the nerves of the driver!
There are lifts for outside- Al has one & I believe he recently posted about it & gave the website for someone else. As for inside, some use lifts here- Ann (abbaschild) has one-
I think I saw a picture of it on one of her albums (Ann?).
There are also stair/chair glides- sit in the chair, turn it on & glide up the stairs.
These can be purchased (they are expensive around $3000) or some companies will rent them. The problem with these are they will not serve you long, depending on your progression. Once you can not transfer safely to the chair or if trunk weakness sets in, this is no longer practical. Renting to buy time until you have another solution, i.e. building/renovating a first floor bedroom & bath would be an option though.
I don't know if there would be any lifts available from MDA or ALSA. No harm in asking.
I'd also ask about a stair glide. I have heard these are available on occasion.