In most cases, you have up to six years from the date you first experienced the disrepair to take legal action. If anyone living in the property has been made ill because of the conditions they have been living in, they must claim within 3 years, if they are an adult, but they have 3 years from the date of their 18th birthday to claim for illness, if they are under 18. However, it is recommended to seek legal advice as soon as possible, as there may be specific deadlines or requirements that apply to your situation.