The Massachusetts Museum of Contemporary Art in North Adams, which began with high hopes and, in some quarters skepticism, marks its 15th anniversary this year. In doing so, it is also setting the stage for completion of the final piece of its construction, one that will enhance the experience for visitors and better link the museum to downtown.

With the passage Thursday of legislation by the state House of Representatives that includes a $25 million grant to complete the $55 million project, work will begin to finish phase three by 2016. The Senate is expected to take up the bill soon and from there it will go to the desk of Governor Deval Patrick. The museum will provide the other $30 million, with $18 million of that funding to be set aside for maintenance in the decades ahead.

The addition of 130,000 square feet of renovated gallery space will bring the square footage to 600,000, and enable visitors to take a circular loop of the entire museum. The museum has emerged as a performing arts venue, most notably with Solid Sound and Fresh Grass, and the addition of bathrooms and other amenities will make it more attractive to concert-goers. A remodeled West Main Street entrance will better link the 16-acre campus to downtown and, when completed, the Greylock Market.

As Mass MoCA Director Joseph Thompson observed in today’s Eagle, the museum’s expansion along with that of the Clark Art Institute in Williamstown will mean that visitors will need two days rather than one to do justice to both. That will have an obvious benefit for motels and restaurants in both communities.

Mass MoCA decided early on that rather than disguise the fact that its exhibits were in old mill buildings that once comprised Sprague Electric it would draw attention to the personality and stamina of these historic buildings. These structures soon found new meaning in a way that could not have been predicted when they were built. In 2016, 20 years after this ambitious and at times daunting renovation project got underway, Mass MoCA will be poised for a bright future, to the benefit of its host city and the Berkshires.