If you have not been served with a party wall notice by your neighbour then it may be that the proposed works are not notifiable under the Act, however there are occurrences where the works are notifiable but the neighbour has not served prior notice. In either case we would recommend giving us a call for further advice as the action required will vary depending on the circumstances. In the immediate term however you could ask your neighbour to cease works until confirmation has been provided by a party wall professional, and take photographs of your property to record its condition.