A 20-unit condominium development in West Roxbury is billed as one of the city’s most environmentally sensitive residential projects ever proposed, but neighbors raised objections about density and potential impacts on nearby wetlands.

The Allandale Residences project cleared a key permitting hurdle Thursday after developer Jacqueline Nunez convinced Boston Redevelopment Authority directors of the project’s merits.

Nunez’s WonderGroup has developed approximately 50 residential units in Boston over the past decade, mainly through rehabilitation of existing buildings. She set a goal of net-zero energy consumption for the new cluster development, which would be built on a 2-acre parcel near Brigham and Women’s Faulkner Hospital and the city’s 86-acre Allandale Woods nature preserve.

“When I was on the site, with the sloping topography and the south-facing orientation, it just felt like a perfect opportunity to do something forward-thinking and special,” Nunez said.

In addition to four condos in a renovated single-family home, the project would include 16 new townhouses built with steeply-pitched gabled roofs equipped with photovoltaic solar panels. The homes would be built to attain LEED Platinum certification. The project also will be designed under Fortified Home certification standards to withstand extreme weather. Those measures added approximately 25 percent to the $20 million cost of the project, Nunez said, and drove the density requirements.

After neighbors raised concerns, Nunes moved the new construction out of a buffer zone surrounding off-site wetlands. As a condition of approval, WonderGroup will donate $50,000 to the Boston Parks Department for the benefit of Allandale Woods.

The project still needs variances from the Boston zoning board of appeal. A hearing has not been scheduled.