This past week, the National Capital Planning Commission (NCPC) approved a 17-and-a-half-foot-tall glass box for the National Mall. The box’s purpose? To be a visitor screening center for the Washington Monument.

The Washington Business Journal reported that the National Park Service (NPS) considered around 40 design options before settling on the current iteration. Near the monument, four geothermal wells will also be drilled in order for them to power the security center.

The new building will be located at the base of the monument and will replace the existing security center. Up to 25 visitors will be able to visit the new building at a time.

According to the Washington Business Journal, the structure will be constructed out of ballistic-rated laminated glass of polycarbonate with a metal mesh insert. To mitigate heat gain, the roof will be made of either fritted glass or tinted glass.

To construct the box, the NPS has requested $9.4 million in the 2017 federal budget. Each year, the screening center will cost the District $400,000 to operate.

The Washington Monument won’t open to the public until at least 2019 due to elevator repairs.

• A glass box will be added to the National Mall landscape. Here's why. [Washington Business Journal]

• Washington Monument closed until 2019 [Curbed DC]