Six months after the United Kingdom’s surprise decision in June 2016 to leave the European Union, a membership survey by the Royal Institute of British Architects (RIBA) revealed the immediate impact on the construction sector: 60 percent of architects had seen work delayed, and 37 percent reported canceled projects. This initial wobble did not turn into a full-blown crash, and the latest data from the influential research firm IHS Markit shows continued expansion in the sector, albeit with slowed growth attributable to Brexit uncertainty. Now, with less than six months remaining until the scheduled withdrawal date of March 2019, the UK’s future economic prospects remain hotly contested, but there is also growing concern that the terms of departure will be damaging to its architectural profession—with one of the country’s most prominent firms, Foster & Partners, even thinking about relocating.

There is, as yet, no agreement on new rules on trade, migration, or regulation to replace those enacted over the last 45 years. For the UK’s construction sector as a whole, this raises the threat of costlier imported materials and labor shortages. More than a quarter of London’s construction workers come from elsewhere in the EU, though the proportion is lower outside the capital. For architects specifically, there are unanswered questions over matters ranging from the mutual recognition of qualifications across the EU to the tariff-free trade in services within the single market.

Perhaps most significant is the threat to recruitment and to the diverse composition of the profession. One in five architects working in the UK are from other EU countries, but of the “four freedoms” enjoyed by EU members—the free movement of goods, services, capital, and persons—it is the last that the UK government is most determined to end. In October, Prime Minister Theresa May announced that EU citizens would no longer enjoy preferential immigration status after Brexit and must apply for work visas. Until now, architects have often avoided recruiting staff who require visas, due to the cost and administrative overhead and the poor chance of success. In the six months before April 2018, only 5 percent of visa applications by non-EU architects were accepted, according to law firm Eversheds Sutherland. A new minimum salary threshold proposed by the UK government will increase the difficulty of hiring early-career architects.

Even if EU architects were permitted to work in the UK, Brexit may already have lessened their desire to do so. Recent data from the Architects Registration Board shows a 42 percent fall in the number of European architects registering in the UK since the referendum. “The number and quality of international applicants has dropped very significantly since the vote,” says Friedrich Ludewig, director of London-based Acme. He employs over 90 people, of whom fewer than 20 percent are from the UK. “We don’t believe that bureaucratic hurdles are putting applicants off—at least not yet. Rather, there seems to be a growing sense abroad that the UK isn’t such a friendly place anymore, and so people might be choosing Paris, Berlin, or Zurich instead.”

Concern that firms many not have the same access to talent has led some to consider contingency planning. Matthew Streets, managing partner at Foster & Partners, told the Architects Journal in June that the firm would, regrettably, have to consider relocation “if Brexit means we can’t attract world talent.” Around half of its 1,061 UK staff are from other EU countries. Newcastle-based Ryder Architecture announced in October that it will shortly open an Amsterdam outpost. The firm carries out less than 10 percent of its business in the EU but hopes to increase that figure, says managing partner Mark Thompson. “Brexit is the catalyst for us though—the opening of a Dutch office will head off the threat of losing EU staff in the wake of a ‘No Deal.’ ”

Pragmatic architectural practices may adapt and even thrive following Brexit. But to lose the diverse experiences and perspectives contributed by people from the 27 remaining EU states would be a major blow to the culture and character of the architectural profession in the UK.