As part of the series, we interviewed architect Daniel Libeskind who masterplanned the rebuilding of the site in New York following the attack in 2001.
"Everything changed in architecture" after the 9/11 attacks, he told us in an exclusive interview.
This week also saw the announcement of the Dezeen Awards 2021 shortlists.
We announced the shortlisted projects in the architecture, interiors, design, sustainability and media categories throughout the week.
Information on all the shortlisted projects can be found on the Dezeen Awards website.
Note Design Studio created a leafy installation made from one of Vestre's old fair stands while Crafting Plastics and Office MMK presented a scent-infused 3D-printed room divider at the furniture fair.
In London, British architecture studio Stufish revealed its design for a temporary performance venue that will be built to host Swedish pop group ABBA's reunion tour.
The 3,000 capacity arena will be built from mass timber and host the band's virtual reunion tour from 27 May 2022.
Continuing the debate over the validity of architects designing airports, Pritzker Prize-winning architect Norman Foster called architects that walk away from designing airports "hypocritical".
"I do feel passionately that we have to address the infrastructure of mobility," he said in a TV interview. "We have to reduce its carbon footprint, like everything else. We can't walk away from it. We can't adopt a hypocritical moral stance."
In the US, Apple's former design director BJ Siegel has set up a company that aims to bring the computer company's ethos to the housing sector.
In an exclusive interview, Siegel explained how the company is building mass timber housing from a kit of components built in factories in the US.
Popular projects this week included a renovation of a mid-century residence in Los Angeles and a house with twisted brick walls in the Indian city of Trivandrum.
Our lookbook this week focused on Shaker-style interiors.