Nuveen has pledged to cut emissions across its £133bn property portfolio.
The announcement by the US-based group, which owns 70 St Mary Axe in London, is possibly the largest climate commitment by a global real estate company.
Nuveen said it would overhaul its buildings, including fitting solar panels and better insulation, in a bid to achieve net zero emissions by 2040.
It plans to shift to 100% renewable energy while reducing energy consumption by 30% by 2025, and move to a policy of refurbishment rather than redevelopment.
