KAREN: One of the, uh, unique things about Gaithersburg is that it's home to one of the original international latitude observatories.

Observatory Park, which is just a few blocks from here, is this tiny little building, and they operated from 1899 to 1982, measuring the wobble of the Earth on its polar axis.

They were measuring distances between Earth and these different stars and the work they did there helped build GPS.

You might not have GPS on your phones if it weren't for that work.

SARAH: There is still a scientific presence in Gaithersburg.

NIST is the National Institute of Standards and Technology, it is an agency within the Department of Commerce, and it actually started back with the US Constitution, Congress decided weights and measures needed to be standardized.

From port to port, a pound was a completely different pound in Boston from it was in Baltimore, and standards were very important for fair trade, not just statewide but also internationally.

KEITH: NIST moved to Gaithersburg in 1966 and that was because there was land available here to build this large scientific campus.

Most of Gaithersburg was dairy farms at that time.

Today, the NIST campus is 500 acres, about 7,000 staff work here, and we do a variety of things from physics to engineering, material science, computer science.

One really interesting project is our net-zero energy house.

So, this is a facility that NIST uses to do research on devices that can enable a home to generate as much electricity as it uses in a year.

BRIAN: It was during 2011 to 2012 that the construction actually occurred.

It would fit in well in any Gaithersburg neighborhood in that it has all the features that you'd normally have, but yet it has extra systems with regards to heat pumps, air conditioners, water heating systems.

We also have extensive instrumentation, so we can set up laboratory tests inside a house and run them over time, and be able to monitor them remotely.

So, behind me on the floor are heating elements, and each of those heating elements represents a different person.

They would cycle on and off because as people, we generate about 60 to 70 watts.

We're little light bulbs.

And then we have humidifiers that turn on and off, again to represent moisture generation.

And then we interject these gases, in this case, CO2, to emulate what would be associated with the people inside the house breathing.

Then in the morning, they're getting up and they're showering, they're turning on lights, they're cooking.

It's a dry period during the daytime, nothing much is happening, so in those periods, we're actually exporting energy to the grid.

We wanna help the homeowner with reducing their utility bills so the house is more cost-effective over time, so just subtle changes to your house can really help you conserve energy.