Mr. Agarwala did much of the research himself to find the best prices for materials.

WSJ: Building Outside the Box

"A big part of both our work is being able to imagine what something will look like, " said Mr. Agarwala.

WSJ: Building Outside the Box

Mr. Agarwala decided to "like" the Facebook page of Pb Elemental Architecture, whose work the couple admired, to get updates on new designs.

WSJ: Building Outside the Box

Mr. Agarwala started scrolling through the county planning department's map of parcel lines, turning to Google Maps to get a satellite view of streets that looked promising.

WSJ: Building Outside the Box

When Mr. Agarwala emailed Mr. Pardo about the possibility of putting up a prefab house he'd seen on the firm's Facebook page, Mr. Pardo suggested finding land and building from scratch instead.

WSJ: Building Outside the Box