Experience and good interior design craftsmen have come up with solid improvements in housing elements that work for all generations. A good list of them appears on the site Caring.com.
Quickly it becomes obvious that the market for most of these ideas is the elderly, or those who want to "age in place." But they work also for the general population. Who doesn't want easy to use (intuitive) faucets or garbage disposals that don't swallow spoons that have to be fetched out by people with small wrists? Why would a new home not want to make corridors wide enough for wheelchairs--or strollers? Or door handles that are easy to open when you have both arms hoisting grocery bags?
However, the list also invites additions and emendations. If, indeed, the Baby Boomers are the real target, someone might consider why it is that even new retirement communities are usually built so far from shopping, coffee houses, churches, libraries and banks that a car is necessary--or a trip in a community van? Walking is itself a form of outing for the elderly (and everyone else, for that matter). Also, why are the interior designs of so many retirement homes like a cross between a Day's Inn and a hospital ward? Why are the "gardens" almost always placed in front by the street and designed for show rather than use? Interior, landscaped atriums and courtyards and sunny terraces are almost always lacking. A hotel would have better sense, as would a family; why not a retirement home?
Greenhouse features are another attribute of good design, I'd think, for enterprising interior space designers. In Europe, old buildings in Paris or Vienna sport thick walls with an outside window and an inside window set about a foot apart. Inside the space even the most impecunious or handicapped person can winter over geraniums and keep winter-blooming plants like cyclamen fresh and comfortable. For regular houses (not apartments or condos), an attached greenhouse can take the place of a backyard for anyone beyond childrearing age--and is a fine complement to a yard for everyone else.
Another design idea for almost any climate: a suction fan in the roof or attic that removes hot and stale air at night. Even the Georgian (18th century) architects knew about this, yet so many houses today effectively are hermetically sealed. A good roof or attic fan--built in--reduces the need for air conditioning even in Florida during some of the year and in Northern climes or California almost all of the summer.
And the most important design innovation we need? I'd say it's an alternative energy/heating source for a house when storms, hurricanes or earthquakes knock out the grid. It can be natural gas (if the installation doesn't depend on electricity to start it, but can be manually started). Maybe solar, though that will be more expensive.
Instead of such ideas we still have a housing industry that mostly plans for the normal day and for the middle of the life-span.
The government should not be part of fixing any of this, by the way. Just let the private sector sit up and take notice, as it already does in many cases. Government's role should be to help clear the way of regulatory interference.