The practice was parachuted onto the project, on the site of a former nursery in the Eton College Estate conservation area, after a scheme by the landowner's original architects failed to win planning.
Part historic conversion and part new build, the Eldridge Smerin proposals include the remodelling of a Grade II listed Victorian coach house and gardener's cottage, together with the construction of a new, glazed extension.
The existing building will house an entrance hall and bedrooms, while the new addition will create a 'generous' living space linking directly to the garden.
The development is expected to cost around £2,150 per m 2and, once complete, the house will cover 385m 2.
Work on the new-build element of the scheme is not due to start until the spring.