Keltbray has been awarded the first demolition contract by High Speed 2 for its £55.7bn rail line.
The demolition specialist will carry out the £2m contract to demolish the Vezey Wing of the National Temperance Hospital, which currently sits on the site of the proposals for Euston station.
The job will be the first phase of demolition work at the site and will begin in the autumn.
Next year a new scope of work will see the second half of the building – known as the Insul Wing – taken down and replaced by the main site compound for HS2’s Euston works.
In May, London mayor Sadiq Khan called for a rethink on the redevelopment of Euston station because of the disruption it could cause to area.
In an interview with LBC radio, Mr Khan said: “HS2 is a wonderful idea but I have got concerns whether Euston is the right station for the London part of HS2.
“The disruption during building works will cause huge inconvenience, the numbers of homes being destroyed.”
The mayor said he was looking at Old Oak Common as a temporary station option until “some of the issues” at Euston were dealt with.
“Watch this space – I’ll speak to those at HS2 to do right by Euston,” he added.
HS2 also recently named joint venture between Atkins, CH2M and Sener as its engineering delivery partner for phase one of the £55bn rail line in March.
The consortium saw off challenges from WSP Parsons Brinckerhoff and Ramboll and a JV between Bechtel, Jacobs and Idom Merebrook for the 10-year £350m contract.