There are a lot of repairs that need to happen at the National Air and Space Museum. Along with the main roof and the HVAC system, the marble facade and glass curtain wall also need a total refresh. There are also plans to install 1,300 solar panels and innovate over 20 galleries inside.

With renovations expected to begin 2018, the cost for the overhaul is almost $1 billion, making it the most costly project the Smithsonian Institution has ever undertaken.

This Thursday, the Smithsonian Institution provided an information presentation to the National Capital Planning Commission (NCPC) on the building exterior and site wall cladding options for the museum. Currently, the museum consists of four monumental blocks clad in Tennessee Pink marble (limestone) panels separated by three recessed glass bays and alternating marble clad blocks.

While the existing marble panels on the interior are in good condition, the marble cladding on the exterior has experienced “significant warping,” according to the Smithsonian Institution. During the meeting with the NCPC, the Smithsonian Institution sought input on alternatives, which include Tennessee Pink marble, Saint Claire limestone, Echo Lake granite, and Ultra High Performance concrete.

In the below document, see the pros and cons that come with each cladding alternative. Can’t see the document? Go to Scribd here.

The National Air and Space Museum was constructed in 1976. Every year, approximately 7 million people visit the museum, making it one of the world’s most visited museums.