I've recently noticed quite a few gaps and cracks along the ceiling coving and skirting board joints. They are only hairline cracks but today I've found a bigger 3mm crack between the skirting board and the wall by the front door. I've sold the house to a first time buyer and a full structural report had been carried out two months ago, but I don't think subsidence was mentioned in the report. So if the gaps and cracks are not due to subsidence, could it be shrinkage or thermal cracks?