Is it permissible to pray facing a restroom, knowing that the prayer area is fenced and exposed to the sun, and there is no designated prayer area at work?

If the place of prayer is pure, then the presence of a restroom opposite or around it does not harm; because the condition of purity is related to the place itself, not to what surrounds it. If there is impurity in the place of prayer, a prayer rug or something that separates the worshipper from the impurity can be spread, and the prayer will be valid. If the impurity is not certain, there is no dislike. But if it is certain and there is a barrier between it and the worshipper, then the prayer is valid, though disliked, based on the saying of Ibn Hajar al-Haytami: "And the dung heap, meaning the place of dung, and similarly every certain impurity, because by spreading something pure over it, one is opposite to it, and the dislike of being opposite to it has passed."