Police are appealing for information after the front door of a house in Elizabeth Drive, Boghall, Bathgate, was deliberately set alight around 6.15pm on Sunday, 2 January, 2022.
Officers are now urging anyone who may have dash cam footage to come forward.
The occupants of the house were not injured, however, the house was damaged.
Detective Sergeant Ross Collett, Livingston CID, said: "Officers have been carrying out enquiries with neighbours and checking CCTV in the area since the fire, however, are now appealing to anyone who has any information about incident to contact police.
"We are particularly keen to hear from any drivers who were in the area at the time and who may have dashcam footage that may assist our investigation.
"Information can be passed to police via 101 quoting reference number 2137 of Sunday, 2 January, 2022 or anonymously to Crimestoppers on 0800 555 111."