Can a landlord raise the rent because of Healthy Homes upgrades?

There is no special Healthy Homes surcharge, and compliance work does not create any extra right to raise rent. Meeting the standards is a legal obligation on the landlord, the cost of being in the rental business, not an optional extra tenants commission. What remains available is the normal machinery: rent can be increased through the usual process, with proper written notice, no more often than the law allows, and any dispute about level is judged against market rent for comparable properties.

Where upgrades and rent genuinely meet

A warmer, drier, compliant house is often simply worth more on the market than the cold version of itself, and market rent is the standard the rules apply. So compliance work can flow into rent the honest way, by making the property better, rather than as a line-item pass-through. Landlords sometimes propose larger mid-tenancy rent rises tied to substantial improvements by agreement; anything in that territory should be genuinely voluntary, documented, and checked against the current rules on tenancy.govt.nz before anyone signs.

The framing that keeps it fair

• Required work is the landlord's cost; the asset being improved is the landlord's asset.
• Rent increases follow the normal process and cadence regardless of what prompted them.
• A tenant asking for compliance is not requesting a favour, and the request cannot fairly be met with a bill.

Practically: do the work, keep the records, and let the property's quality carry its price. That position is comfortable at the Tribunal, and more importantly it keeps good tenants, which is worth more than any single increase.