This is an interesting way to look at it. For the last three years, we've put most of our savings into building a house which we will own free and clear whenever I get around to writing that last check. How many years' savings did we put aside for each of those years? It's hard to calculate since we don't know how long we'll live, but in three years we've completely cut the major retirement expense of rent or mortgage, dropping the "housing" category of our retirement needs by probably 90% in this low-tax area.
For that matter, that same money also bought us enough land that we could sustainably grow our own food and harvest enough timber to run our wood stove. I don't know that we'll choose to do that, but I guess at this point we're working to save enough to pay taxes and health insurance in retirement. Once we have just that, or a side stream of income that produces that, we have permanent FU money even if we choose to keep working.
Dang. Put it that way, and I think it's time for a couple of rental houses!