We do it for our children without even giving it much thought. When a new baby arrives (even long before a baby arrives) we spend months getting our home ready. We buy a special bed, we "safety proof" the cabinets and the outlets, we buy monitors. We try to keep the environment safe for the developmental stage of the child, making changes as he grows.

First we worry about how clean the floor is, then we put the plants and the breakable items up high. Before we know it, the whole house has been modified in one way or another.

Then when the children are older we stop thinking about it and the house slowly reverts to "grown-up."

But our physical abilities don't stop changing as we mature. Sure, they'll stay more or less the same for several decades if we're lucky. But then, inevitably, we'll begin to notice a little twinge here or there. Our balance won't be quite as good as it once was. We may need a bit more light to see what we're reading (if our arms are long enough to see it at all).

And bit by bit, the house we call home isn't quite as user-friendly as it once was.

Just about every older person I've ever talked with wants to stay at home. And for most, staying at home can be the most economical choice, too.

Assisted living can cost $3,000 to upwards of $6,000 a month, depending on the part of the country you live in. Nursing homes are a whole lot more expensive. If you invest less than the cost of one month of assisted living you can possibly buy extra months or years of living at home just by making a safety assessment and implementing a few cost-effective changes.