Tipperary is one of just five counties in the country not to record an A energy rating for domestic dwellings in the last nine years.
Over 24,500 BER audits were carried out in the Premier County between 2009 and 2017.
The average age of houses subjected to a Building Energy Rating test in Tipperary was 39.
11% of Tipperary houses tested ranked as G which is the poorest rating available – only Roscommon at 12% recorded more.
The most common rating applied in the Premier County was D1 with 14%.
Of the 24,684 houses or apartments tested in Tipperary between 2009 and 2017 not one achieved an A rating – Longford, Westmeath, Leitrim and Roscommon were the only other counties not to get a single top energy rating.
Nationally 3% of the dwellings tested were ranked as A which makes them the most energy efficient.
Meanwhile figures from the Central Statistics Office show oil was the most common home heating source used in Tipperary, accounting for 65%, mains gas was next at 14% followed by solid fuel at 11 and electricity at 10% with LPG at just 1%.