City officials and stories Boston residential developer Harold Brown and his company, Hamilton, gathered on Monday morning to celebrate a groundbreaking for 44 units of housing that will complete Douglass Park on Camden Street and provide more affordable housing than required.

The new, $17. 9 million, 44-unit apartment building at 150 Camden Street in the South End’s Lower Roxbury, completing the multi-building development known as Douglass Park. Originally slated for nine townhouse condos, the site was looked at differently when Hamilton purchased the Park in 2013 for $52 million.

After working with neighbors and the Boston Planning and Development Agency (BPDA), Hamilton President Carl Valeri reported on Monday that the 44-unit building will be delivered with 18 percent affordable housing, some 5 percent above the 13 percent required. The entire complex at Douglass Park, he said, stands at a total of 24 percent affordable units.

“You guys are breaking the mold,” said Councilor Tito Jackson. “When developers say they can’t make the books work, we will point to what you have done here. This is something we will want to replicate in Boston and we will continue to point to this. You were only required to have 13 percent and you added 5 percent and ended up with 18 percent affordable housing in this building.”

On hand for the groundbreaking ceremony were Brian Golden, director of the Boston Planning and Development Agency (BPDA); Jackson; Joshua McFadden of the mayor’s office; and principals of The Hamilton Company, including Founder and Chairman Harold Brown.

“The BPDA is enthusiastic about the opportunities this development will bring to the residents and stakeholders in the South End neighborhood and to the entire city of Boston,” said Golden.

Golden noted that 60,000 more residents will flood into Boston over the next decade, bringing the total to over 700,000 and prompting the need for additional, market-rate, middle-income and working class housing. “This project is another example of The Hamilton Company’s commitment to provide quality housing for a growing city,” said Golden. “It’s a modest addition, but a whole lot of work went into this.”

The new 49,305-square-foot building, which is being built on the last remaining parcel in the development known as Douglass Park, faces out onto Tremont Street near Massachusetts Avenue and just south of athletic fields being developed by Northeastern University.  The new residences will include one-, two-, and three-bedroom units, parking in an adjacent, existing parking garage and extensive, new landscaping. Units in the 5-story building will average 900 square feet and range from 700 square feet for one-bedroom to 1,200-square feet for three-bedrooms. Construction of the building is expected to be completed in late summer of 2017.

Interestingly enough, construction crews found an interesting structure when first digging the foundation. At the moment, those crews are busy removing the foundation of an old railroad roundhouse from the old Boston Elevated Railway. The site had apparently been used as a turnaround location for streetcars at one point in the past.

Founded in 1954 by real estate icon Harold Brown, The Hamilton Company has amassed more than $1.7 billion in residential and commercial assets in the Greater Boston area. Harold Brown, who frequently gives lectures on real estate trends and investment, is also founder of The Hamilton Company Charitable Foundation, of which Ronald Brown is chairman and Jameson Brown is a Board member. The Foundation allocates millions of dollars to local non-profit neighborhood groups, charities and associations annually.