The sustainable real assets specialist opened an office in London, its first outside the US, in October last year.
Rich Lesser is the former CEO of Boston Consulting Group and Jeff Johnson was most recently a managing director at Temasek.
The new hire replaces Lora Brill, who left Orchard Street at the start of the year to join sustainability consultancy Ramboll.
Cathy Zoi's previously served in the Obama administration.
The firm has bolstered its fundraising ranks with Sian Roberts, head of UK institutional distribution.
The firm's newest partner spoke to affiliate title PE Hub Europe about the impact potential of infrastructure and diversity in private markets.
Erich Becker has joined as a decarbonisation partner, while Christina Levin-Rylander will lead the firm's sustainability efforts.
HSF's ESG practice is led by partner Silke Goldberg, and advises on energy transition and climate change, business and human rights, environmental law, governance, greenwashing and responsible investing.
Brookfield's head of transition investing discussed the next stage of the energy transition at Infrastructure Investor Network's Global Summit in Berlin.
Damien Braud joins the firm after it announced a natural capital fund last year.