Ms Rayner is seeking to overhaul planning laws to make it easier for councils to build homes on poor-quality green belt land.
Mr Simões said that L&G will remain a “big player” in the housing market through its separate affordable housing operation.
He said: “There’s a huge need for affordable housing and we’re not building enough homes in the UK. But the plans to do it, we want to be part of that solution.
“Therefore we see a big opportunity that’s both good for society obviously because lots of people are waiting for affordable homes, but also very good for our shareholders.”
The British insurance and investment giant will reap £1.16bn in cash proceeds from the sale once it completes at the end of the year, which values Cala at £1.35bn.
Cala was founded in 1865 and specialises in building high-end properties in the south of England, the Cotswolds and Scotland.
The Edinburgh-based business, which employs 1,300 people across 10 offices, generated £42m in operating profits during the first half of 2024. It has tripled the number of homes it builds each year under L&G’s ownership. It sold just under 3,000 homes last year.
The sale sees Cala return to its previous owner Patron Capital, which offloaded its majority stake in the housebuilder to L&G six years ago.
The deal also sees Sixth Street Partners expand its real estate portfolio, adding to investments in Airbnb, Spotify, Real Madrid and Barcelona football clubs.
Keith Breslauer, managing director and founder of Patron Capital, said the buyers plan to further build Cala and “help tackle the undersupply of homes in the UK”.
The private equity buyers triumphed over FTSE 100 housebuilder Persimmon, which was reportedly a frontrunner in the bidding process.
Mr Simões said that Patron Capital and Sixth Street presented a “really attractive valuation” for Cala and provided “certainty” about the sale completing, allowing L&G to focus on growing its other businesses.