An Taisce is seeking to protect the house known as Ireland's "Alamo" - where the leaders of the 1916 Rising surrendered to the British forces following the fire at the GPO.
Dublin City Council plans to demolish the house at 16 Moore Street as part of the redevelopment of the old Carlton cinema site in the north inner city.
Representatives from An Taisce and the National Graves Authority accompanied architect Mr Arthur Gibney to assess the property over the weekend.
Mr Gibney concluded the property dates from the early 18th century and not the Victorian era, as the original information put before the City Council stated.
A spokesperson for An Taisce said that "given that the decision for demolition was made on the basis of inaccurate reports - both of the age of the house, and of the actual dates of the Rising, should we really rely on their conclusion that it [the house] is 'of limited historical significance'? I think not".
An Taisce claims the demolition of the building would parallel the destruction of Robert Emmet's home at Stephen's Green 20 years ago.