Yes, a landlord can assess their own property using the Healthy Homes Standards guidance and tools published by Tenancy Services. There's no legal requirement to use an independent assessor. In practice, a self-assessment carries more risk at the Tenancy Tribunal than an independent one, particularly for technical judgements like heating capacity calculations, which have been challenged and rejected where they were carried out by a landlord or an unqualified person rather than a qualified assessor. A self-assessment is also harder to defend as objective evidence if a tenant disputes it, since the person making the assessment has a direct financial interest in the outcome. An independent assessment costs more upfront but tends to hold up better as evidence if a dispute reaches a hearing.