This appears to be the house shown as Valetta House which was on the site now occupied by the multi-storey carpark behind the library on Library Road.  The second house is probably a gate lodge or annexe to the main house.

At the time of Griffiths Valuation (1849) Valetta House was occupied by Major Edward W Drew, and Drew is also recorded there in the Topographical Dictionary of Ireland 1837

The censuses of 1911 and 1901 both show a large house and a smaller house on Valetta Avenue.  The larger house (14 rooms) is occupied by the Browett family.  Francis Browett had shops at both 7 and 19 Upr Georges St, selling ironmongery, and had a nursery and fruit business.  He traded as E Browett & Co