In 1970, a new building opened for the church at 16th Street and I Street NW, designed in a brutalist architectural style by Araldo Cossutta, a partner in the firm I. M. Pei & Partners.
Cossutta had previously designed the Christian Science Plaza in Boston.
The concrete building is octagonal in shape.
An adjacent office building was also constructed to house The Christian Science Monitor's Washington Bureau, with a small plaza knitting the two buildings together.

Although many architecture critics admire the building, many members of the Church's congregation disliked it.
The Church began to consider selling the property about 1990, which would likely have led to its demolition.
In an effort to save the building, two groups independent of the Church applied in 1991 to the District of Columbia to have the building listed as a historic landmark.
The congregation opposed the designation, which was not acted on at the time.

The building had been costly to maintain, and was not suited to be re-purposed for another use.
Structural defects include cracking in many spots.
Maintenance costs included $5,000 - 8,000 for changing lightbulbs in the sanctuary, which involved erecting scaffolding.
In 2007, the land itself was sold in 2007 to ICG Properties, which owns an adjacent property on K Street, and the developer leased the land back to the church.

This renewed threat to the building led to reconsideration of the 1991 application for historic landmark status.
In December 2007 the application was approved by a unanimous vote.
After the city turned down a demolition permit request from the Church in July 2008, the Church filed a lawsuit alleging violation of the Free Exercise clause of the First Amendment along with the Religious Freedom Restoration Act and the Religious Land Use and Institutionalized Persons Act of 2000 (RLUIPA).
Opponents of the historic landmark designation argued that it violated the 1993 Religious Freedom Restoration Act and subsequent laws by imposing a substantial burden on the church.
 On May 12, 2009, the District of Columbia approved a demolition permit for the building, citing hardships on the building's owner and the possibility of the congregation's demise if demolition were not approved.
The approval was contingent upon the congregation's relocating to another facility close to that of Third Church.

As of October 7, 2013, with all legal issues resolved and with local approval in hand for a planned unit development, with commercial and religious uses, the owners applied for the final demolition permit.
Demolition of the church building began on February 24, 2014.
The 1971 Third Church  building was replaced by an office building.
On July 24, 2015, Third Church merged with First Church of Christ, Scientist.
First Church moved from its former location in the Adams Morgan neighborhood.
First Church now meets in a portion of the building that replaced Third Church at 910 16th St. NW behind a dramatic mirrored glass entrance.
In 1970, a new building opened for the church at 16th Street and I Street NW, designed in a brutalist architectural style by Araldo Cossutta, a partner in the firm I. M. Pei & Partners. Cossutta had previously designed the Christian Science Plaza in Boston. The concrete building is octagonal in shape. An adjacent office building was also constructed to house The Christian Science Monitor's Washington Bureau, with a small plaza knitting the two buildings together.
Although many architecture critics admire the building, many members of the Church's congregation disliked it. The Church began to consider selling the property about 1990, which would likely have led to its demolition. In an effort to save the building, two groups independent of the Church applied in 1991 to the District of Columbia to have the building listed as a historic landmark. The congregation opposed the designation, which was not acted on at the time.
The building had been costly to maintain, and was not suited to be re-purposed for another use. Structural defects include cracking in many spots. Maintenance costs included $5,000 - 8,000 for changing lightbulbs in the sanctuary, which involved erecting scaffolding. In 2007, the land itself was sold in 2007 to ICG Properties, which owns an adjacent property on K Street, and the developer leased the land back to the church.
This renewed threat to the building led to reconsideration of the 1991 application for historic landmark status. In December 2007 the application was approved by a unanimous vote. After the city turned down a demolition permit request from the Church in July 2008, the Church filed a lawsuit alleging violation of the Free Exercise clause of the First Amendment along with the Religious Freedom Restoration Act and the Religious Land Use and Institutionalized Persons Act of 2000 (RLUIPA). Opponents of the historic landmark designation argued that it violated the 1993 Religious Freedom Restoration Act and subsequent laws by imposing a substantial burden on the church.  On May 12, 2009, the District of Columbia approved a demolition permit for the building, citing hardships on the building's owner and the possibility of the congregation's demise if demolition were not approved. The approval was contingent upon the congregation's relocating to another facility close to that of Third Church.
As of October 7, 2013, with all legal issues resolved and with local approval in hand for a planned unit development, with commercial and religious uses, the owners applied for the final demolition permit. Demolition of the church building began on February 24, 2014. The 1971 Third Church  building was replaced by an office building. On July 24, 2015, Third Church merged with First Church of Christ, Scientist. First Church moved from its former location in the Adams Morgan neighborhood. First Church now meets in a portion of the building that replaced Third Church at 910 16th St. NW behind a dramatic mirrored glass entrance.
Third Church of Christ, Scientist (Washington, D.C.)