David Brancaccio

One segment was prompted by a visit I made many years ago to a renovated duplex in the Boston area.

There, a physicist...

had tried to make her home as environmentally friendly as her budget and the technology of the time could make it.

Oh.

It was the winter of 2008.

I was on assignment for PBS television.

We didn't know the great financial crisis was coming later that year, but we did know the climate crisis was unfolding.

And look at these lights.

This is a cool light fixture.

What are we looking at here?

Back then, a recessed, low-energy LED ceiling fixture was a hard-to-find item.

I remember her paying $800 for each 18 years ago, but now you can get one at the hardware store for $26 and change.

When we contacted Dr. Mugabe all these years later, she was still in the house, the bones of which have just turned 100 years old.

And what we found is proof that you don't have to build new to be cutting edge.

What comes next year is from a fresh tour of the place.

The day of the recent visit, a crew was taking her house to the next level of energy efficiency, connecting its heating and cooling system to an underground geothermal well.

Magavi, in the intervening years, has become head of a nonprofit that works with utility companies to put in networked geothermal for whole neighborhoods, even towns.

Now it was her turn.

dig four to six feet into the soil even during a chilly New England winter, and there's a fairly constant moderate temperature that can be used to make a house warmer or cooler without much energy through the magic of thermodynamics.

When she first renovated, she thought to put in an air distribution system into the walls that could be adapted to new technology as it becomes available, and now here it is.