The hall was opened on 5 November 1925.
Quoted from the Goulburn Post of that date:
"The Roslyn Memorial Hall which will be opened tonight has been erected at a cost of 1000 (pounds). It is built of dressed bluestone, and is 50ft long by 25 ft wide, with a porch at front. The marble memorial tablet which will be unveiled by Colonel Mccartney was made by Turner's of Goulburn. The stonework is by Harry Rabjohns and the furnishings by L.E. Goodhew of Crookwell."
http://trove.nla.gov.au/ndp/del/article/102755216?searchTerm=Roslyn%20Hall&searchLimits=#pstart9757575
From the hall you can also see the remains of the Goulburn to Crookwell railway line. Unfortunately, trains no longer run here.