BUILDING 20 AT FACEBOOK’S MENLO PARK
HEADQUARTERS, ALSO KNOWN AS MPK 20,
WAS DESIGNED BY FRANK GEHRY and opened in
March 2015. The 9-acre garden on the roof features roughly 360
trees and 110,000 shrubs, a half-mile walking loop and a meeting
room. The irrigation system is a typical drip and sprinkler system
that sits between the 18 inches of soil and 12-48 inches of extended polystyrene geofoam, which provides a lightweight base to
anchor trees and sculpt hills and other landscaping features.
The social media giant opts for an innovative gathering space
“It’s really something
to come out of a work-
ing environment, go up
a few flights of stairs
and be in a park,” says
Rick Canaday, General
Manager, California, for
Insulfoam, which sup-
plied the 150,000 cubic
feet of geofoam. “The
minimum R-value on
that roof is R-60, so it
really takes the heating
and cooling load off of
the building. You can-
not get a 110-degree day
to pass through that
roof. The highest point
is over R-200, so the
energy savings are just
The geofoam used to sculpt MPK 20’s hills and curved fea-
tures allowed the use of plants with deep roots, such as trees,
without overloading the roof with too much heavy soil. The
foam layers range from 12 inches up to 48 inches where there
Trees and bushes are planted in wells dug into the foam.
This keeps the roots from penetrating into the building and
limits how big the tree can grow. The rest of the foam was
then built up around the wells to create a flat surface.
Create a rooftop park with creative landscaping
features and amenities.
Lightweight geofoam used to create hills and curved landscaping.
The 9-acre garden features trees, shrubs and a walking loop.
20 BUILDINGS 06.16