The United States Embassy on Sussex Drive, long one of the most popular destinations for curious visitors during Doors Open Ottawa, won't be opening its doors this year.

In an emailed statement, a spokesperson from the embassy said it would not be taking part this year because staff members will be busy preparing to support American visitors attending the G7 Summit in Charlevoix, Que.

It's the first time in eight years the embassy hasn't been on the list of Doors Open venues.

Doors Open Ottawa will take place on June 2 and 3, while the G7 summit will happen the following weekend.

Doors Open is an international movement where people have the opportunity to tour unique architectural and heritage buildings.

'Always sold out'

The U.S. Embassy has taken part in the annual event since 2010, according to Amy Kudrinko, an event co-ordinator for Doors Open Ottawa.

While the event is free for participants, some organizations, such as the U.S. Embassy, require pre-registration.

"Every year that they had participated it had always sold out," Kudrinko said.

There are 145 buildings taking part in the event this year, she said, down from the record 162 in 2017 for Canada's anniversary year, but higher than the average of 130.

Notable new additions this year include the OC Transpo Bus and Train Simulator Training Facility on Belfast Road and Hydro Ottawa's new hydroelectric facility at Chaudière Falls, Kudrinko said.