Construction is now officially underway on New Hampshire's first net-zero, multi-family housing project.

Rep. Annie Kuster joined state and local officials for the groundbreaking Wednesday in Lebanon.

The building’s 29 units will not only be energy-neutral, their electric use offset by solar panels, but also affordable. Resident incomes will be capped at about 60 percent of the area median, or about $42,000 for a family of four.

Twin Pines Housing, the non-profit behind the project, is also welcoming its first residents this week at another site across town. That building will house the chronically homeless and extremely low income.

The Upper Valley, like many areas of the state, is in the midst of a significant housing shortage. The region is estimated to be short about 5,000 units, driving up rents and home prices.