<p>Part L of the Building Regulations came into force on April 6. All planning applications submitted from now on must comply with the new regulations. Developments with full building plans approved before April 6 can build to the old Part L requirements, provided they start on site before April 1 2007. Several versions of the SAP software needed to calculate compliance are still not approved by the BRE but Dave Mitchell, technical director of the HBF, said: “The panic has died down, since four to six months worth of plans went in for approval in the month before implementation which has bought developers time.” <br><br><b>NEXT KEY DATE: The end of the transition period is April 1 2007</b></p>