You can significantly improve convenience and user efficiency by making inexpensive changes throughout your house, and I'm not referring to automation of the whole house, even though you could take a baby step developing a "smart home" simply by spending a little more for motion-activated switches or automated deadbolts and thermostats. All of what I'm describing can be purchased on-line or at the home improvement retailers.
But even if you don't want to go high-tech, boost the convenience of your home simply by swapping out round door knobs and traditional light switches. Every area in the house should have these universally designed basics promoting convenience . Each is simple and intuitive to use by the most people, whether standing or seated, with low probability for error and includes multiple ways of accomplishing the same goal.
Why replace doorknobs with lever handles? Traditional knobs can only be opened by grasping and twisting, difficult for someone with arthritis or a weak grip (child); however, a lever handle can be pushed down or pulled upward to open the door by using ones knee or elbow, or by lassoing a rope or belt around the handle for someone who is seated (or who has fallen). Imagine someone with an armful of boxes attempting to turn a round door knob versus pushing/pulling open a lever handle and you'll picture the convenience and safety upgrade.
Here's a rocker switch with a timer, these also come in motion activated models.
For the same reasons another universally designed standard is the rocker or paddle switch, the user can turn on the lights in multiple ways. (Dimmer switches too.) Again, think of these as easy for kids.
Many UD fixtures and equipment can be activated by push button, remote control, timer or motion. The appropriate application for different rooms depends on the desired outcome and preference but the end result is ease (low effort, personal energy savings) and safety.
As for placement of electrical controls, outlets should be no lower than 18 inches off the floor and preferably 24 inches for easier reach by standing users. Switches should be no higher than 44 inches above the floor (36"- 38" ideal) for comfortable reach by someone seated. You want to avoid bending, stooping, stretching or kneeling.
(A side note for new construction or remodeling when you're building a new wall, using these different heights for controls doesn't add a single cent of extra expense to the project.)
And finally in cases where it's impractical to widen a doorway, one alternative among other solutions is the offset door hinge. Also known as swing-away or swing-clear, these hinges give you an additional 1.5 to 2 inches of additional clearance, the thickness of the door. Ideally you'd widen the doorway for 36 inches clearance (a 3'-0" door) but sometimes that's not possible so the offset hinge is an inexpensive fix.
With the exception of changing the height of outlets and switches in a finished wall, replacing doorknobs, light switches and other fixtures with the universally designed option isn't expensive and can be achieved with a trip to the hardware store. Obviously you should hire an electrician if you don't know what you're doing in that realm but you don't need a contractor to boost the convenience and safety of your home with these staples of UD.
Next I define the difference between visitability and livability before I begin describing the most important rooms in the house.