He built a large new family home at Churchtown House, Knockane.
In 1800 he was granted permission to hold four fairs a year and one market a week in Blennerville, which providing him with extra income.
On 22 September 1809 he was created a baronet of Blennerville in the County of Kerry, in the Baronetage of the United Kingdom.
[3] He was confirmed the right to bear the family coat of arms a year earlier.
Blennerhassett married his first cousin, Millicent Agnes Yielding, the daughter of Richard Yielding, on 31 October 1762; she was killed in an accident in 1801, receiving a blow from one of the sails of their windmill.