BOSTON—City and state officials recently celebrated the opening of the first phase of the redevelopment of the Washington Beech public housing project in the city’s Roslindale neighborhood.

Under the redevelopment effort, the Boston Housing Authority and developer Trinity Financial are replacing 266 old units with 206 new units on site and 136 more off site. The first phase features 100 new units.

Washington Beech’s new site design reduces density to fit with the surrounding neighborhood. A variety of unit types replace the old institutional walk-ups, including a mid-rise elevator building, small garden apartments, duplexes over flats, and townhouses.

The first-phase financing included low-income housing tax credits. RBC Capital Markets’ Tax Credit Equity Group, the tax credit syndicator, teamed with investor Nationwide Life Insurance Co. to provide $21.2 million.

RBC has provided nearly $150 million in equity to public housing revitalization in the Boston area to help create almost 1,000 units. Nationally, the tax credit group has invested more than $3 billion in more than 500 affordable housing developments with nearly 43,000 homes.

The overall redevelopment of Washington Beech is expected to cost approximately $100 million. About $20 million will be provided through federal HOPE VI funds and $10 million will come from federal American Recovery and Reinvestment Act funding, according to the city.