A cherished and historical boathouse where the doctor who discovered Down’s syndrome once lived has been earmarked for protection by English Heritage.

The Normansfield Boathouse, which sits on the west bank of the Thames between Teddington Lock and Kingston Bridge, was already protected by a council conservation area this year, and is now in line for a final badge of approval.

Plans by developers to alter the site and move the boathouse back from the river drove campaigners to action in November last year, as they felt the treasured building, built for Dr John Langdon Haydon Down, would be lost forever.

Since then the council has backed preservation of the site and deemed the whole river frontage between Kingston Bridge and Broom Road recreation ground part of the Hampton Wick Conservation Area.

English Heritage has put together a report, which has been submitted to the Secretary of State for Culture, who will decide if it has special architectural or historic interest.

It is still in the process of assessing the building.

It was designed in 1884 by architect Rowland Plumbe and features a red brick basement, timber-framed superstructure with rendered panels and a timber platform.

Inside the boathouse is unusually and lavishly decorated and closely resembles the theatre at Normansfield, designed by Plumbe and built in 1877 to 1879.

Campaigner Anumita Sharma, who has fought to protect the boathouse from redevelopment, said: “What is nice is the description of the boathouse by English Heritage.

“It was designed by the same architect who did the Normansfield Theatre so it seems it is even more significant than we first thought.”

Dr Langdon-Down, who the unique two-floor Victorian boathouse was built for, lived in Broom Close, Teddington, and first discovered and developed treatments for Down’s syndrome.