Lowcock cited satellite imagery that suggests 17 villages have been completely destroyed in airstrikes, as part of what he called a "scorched earth" policy by the Syrian Government.
He also noted the high frequency of attacks on civilian infrastructure, despite a process known as deconfliction under which the UN supplies the co-ordinates of hospitals, schools, bakeries and other civilian infrastructure to Russia, Turkey and the United States, with the goal of preventing hits on them. Russian and Syrian warplanes are the only ones active in the skies over Idlib.
At a minimum, Lowcock said, the deconfliction process "is not proving effective" to avert attacks on civilian infrastructure.
It was also possible, he said, that the co-ordinates are being used to deliberately target facilities.
According to Physicians for Human Rights, there have been 46 reported attacks on medical facilities since the Syrian Government launched an offensive in April, backed by Russian warplanes, to regain control of the last areas still controlled by the opposition.
Of those, 16 have been verified by the group, and 14 were against facilities that the UN had identified to Russia as hospitals, according to testimony delivered to the Security Council on Wednesday by Physicians for Human Rights Director of Policy Susannah Sirkin. She reminded the council that targeting medical facilities is considered a war crime under international law.
Russia has denied that it is using any of the information it receives to target hospitals, but some international aid agencies such as Doctors Without Borders have already stopped sharing the co-ordinates of their operations with the UN.
In an appeal last week to the international community to do more to prevent the bloodshed in Syria, UN Commissioner for Human Rights Michelle Bachelet said she did not believe the amount of damage being inflicted on hospitals as well as schools, bakeries and other civilian infrastructure was a coincidence.
"These are civilian objects, and it seems highly unlikely, given the persistent pattern of such attacks, that they are all being hit by accident," she said.