Mae adran 91 o Ddeddf Rhentu Cartrefi (Cymru) 2016 yn gosod rhwymedigaeth ar landlord i sicrhau bod yr eiddo mae'n eu gosod ar rent yn ffit i bobl fyw ynddynt ar ddechrau contract meddiannaeth newydd a thrwy gydol y contract hwnnw.
Section 91 of the Renting Homes (Wales) Act 2016 places an obligation on a landlord to ensure the property they rent is fit for human habitation at the start of and during the length of the new occupation contract. The regulations set out the considerations a landlord must make in determining whether a property is fit for human habitation. These include damp and mould growth, noise, sanitation and drainage.