Do you have an accessible bathroom on an upper floor? Are you in a wheelchair, and can you transfer well to other chairs? Have you seen those motorized seats that attach to stairs? (stairlifts) Just thinking maybe it would be easier and better to gain access to the upstairs than remodeling the downstairs?

http://www.buystairlifts.net/handicap-stair-lift.html

I am familiar with the Stair glider, I have one, that is not the problem, it is getting into and using the bathroom I have, that is not handicap accessible.

what kind of space do you have? if you need t expand the 1/2 bath for access - where could you make changes? A sketch with measurements or pictures would help

John, without a plan it is very hard to advise you. Realistically speaking you should find a local Architect or designer fully familiar with the ADA and your local codes regarding ADA compliance to help you figure out how to get you your accessible bath space. It's a fairly specialized requirement that an ADA experienced pro would be a big help with. There may be some VA resources to help you finance some or part of the project.

Here are some places to look for more ideas and information.
Please take from this whatever is helpful. Best wishes.

Houzz
1.) Go to Houzz Ideabooks and enter "Universal Design" in the search box.
2.) Go to Houzz.com/Handicap-accessible
3.) Go to Houzz Design Dilemma and enter "handicapped" in the search box.

Universal Design
1.) www.universaldesignstyle.com
2.) www.schaefferconstruction.com specializes in Universal Design

Handicap Access
1.) The Americans with Disabilities Act (ADA) site has specific measurements for wheelchair turning radius, angle of ramps, handrails, everything.
www.ada.gov/adast94.pdf
www.ada.gov/
2.) ADA Ramps: ADA Code 4.8

Aging-in-Place
1.) Consult with a Certified Aging-in-Place Specialist. You can find one through the nahb.org website.
2.) Go to Houzz Professionals and contact Brickwood Builders. They are Certified Aging-in-Place Specialists. (For you other Houzz Professionals who are CAPS, please add your name to this list!)