The failure of the Government’s Carbon Emissions Reduction Target  funding package to deliver hit the firm’s sales volumes in 2010.

Chairman Tim Ross said: “Superglass has made positive progress in the period under review against a backdrop of a CERT market which continues to lag expectations.

“The timing and extent of the anticipated upturn in CERT-related volumes remain difficult to predict,” he added.

Legislation to extend CERT was passed into law in August 2010. But Superglass said anticipated growth from the extension of the scheme had not materialised.

Government targets require 1.4 m cavity wall and 2.1m lofts to be insulated by December 2012. But estimates of actual installations for 2010 show the programme is slipping behind schedule. So far contractors have complete around 400,000 cavity wall and 700,000 loft installations.

Superglass said it had seen an upturn in activity since February but could not predict whether enough work would come through to meet Government targets.

In the six months to February 2011, Superglass made a pretax loss of £2.2m on revenue down from £16.8m last time to £15m.