The hours during which lifts in Portcullis House were out of service in 2011 and January 2012 were as follows:<Table width="100%" summary="" cellspacing="3" cellpadding="3" border="0"><thead><tr><th>2011</th></tr></thead><TR><TD>Lift reference</TD><TD>Hours out of service</TD></TR><TR><TD>HOP 101 NW Corner Portcullis House</TD><TD>7.50</TD></TR><TR><TD>HOP 102 NW Corner Portcullis House</TD><TD>3.50</TD></TR><TR><TD>HOP 103 NE Corner Portcullis House</TD><TD>10.50</TD></TR><TR><TD>HOP 104 NE Corner Portcullis House</TD><TD>113.00</TD></TR><TR><TD>HOP 105 SE Corner Portcullis House</TD><TD>5.00</TD></TR><TR><TD>HOP 106 SE Corner Portcullis House</TD><TD>17.00</TD></TR><TR><TD>HOP 107 SW Corner Portcullis House</TD><TD>2.50</TD></TR><TR><TD>HOP 108 SW Corner Portcullis House</TD><TD>2.00</TD></TR><TR><TD>Total</TD><TD>161.00</TD></TR></Table><Table width="100%" summary="" cellspacing="3" cellpadding="3" border="0"><thead><tr><th>January 2012</th></tr></thead><TR><TD>Lift reference</TD><TD>Hours out of service</TD></TR><TR><TD>HOP 101 NW Corner Portcullis House</TD><TD>0</TD></TR><TR><TD>HOP 102 NW Corner Portcullis House</TD><TD>2.00</TD></TR><TR><TD>HOP 103 NE Corner Portcullis House</TD><TD>2.00</TD></TR><TR><TD>HOP 104 NE Corner Portcullis House</TD><TD>3.00</TD></TR><TR><TD>HOP 105 SE Corner Portcullis House</TD><TD>0</TD></TR><TR><TD>HOP 106 SE Corner Portcullis House</TD><TD>1.00</TD></TR><TR><TD>HOP 107 SW Corner Portcullis House</TD><TD>600.00</TD></TR><TR><TD>HOP 108 SW Corner Portcullis House</TD><TD>0</TD></TR><TR><TD>Total</TD><TD>608.00</TD></TR></Table>The main reasons for taking the lifts out of service have been difficulties with lighting, drive motors, guide rollers, safety edges and door locks.The guide rollers are bespoke items and replacements had to be specially made. The drive units which failed are now obsolete and therefore had to be repaired. In case these parts fail in the future, a number of spare guide rollers were made at the same time and alternative replacement drive units are being investigated.There has been an unusually high number of lift breakdowns since the start of the new year and the reasons are being investigated. The Parliamentary Estates Directorate (PED) is working with the lift contractor to address the matter. Contributing factors have been staff sickness and a temporary loss of expertise following a change in lift contractor in August 2011.A new lift monitoring system is currently being installed which will monitor the performance of all lifts in Portcullis House and will provide better information on any problems. In addition, an estate-wide lift refurbishment programme is currently being developed by the PED Programme Office.The hon. Member might find it helpful to speak directly to the Parliamentary Director of Estates on these detailed matters.