The four adjacent townhouse buildings are getting a complete face lift.
FYI, one of the single family Italianate row houses, No 35 E 60th St, used to be known as the Darling House, after an early owner Mr. William Augustus Darling , who lived in the single family house when he run for mayor of NY. In the 1920s 60th St was widened and the stoop of the Darling house was turned sideways.
The developer of 520 Park Ave currently has scaffoldings up and are re-doing the facade and the storefronts. I think the facades will be a light beige stucco (you can see the color behind the scaffolding), and I have also heard there will be some limestone details on the street level.
The last few evenings these has also been light testings happening on the facade of Christ Church - apparently the developer is also adding lights to the facade of the church and the Groilier Club. Really beautifying the whole block.