A tenant can ask a landlord for the Healthy Homes compliance statement at any time, since it's a document the landlord is legally required to hold and provide at or before the start of the tenancy, and must respond within 21 days of a request. There's no separate legal right for a tenant to demand a full independent assessment be carried out, though a tenant can raise specific concerns about heating, insulation, ventilation, moisture, or draughts directly with the landlord or property manager in writing. If those concerns aren't addressed, a tenant can apply to the Tenancy Tribunal, where an adjudicator can order an assessment or make a finding based on the evidence presented. Putting a request in writing matters, since written notification establishes that a landlord knew about a problem.