The Healthy Homes insulation standard, explained

Insulation is the standard most likely to be assumed compliant and least likely to have the paperwork to show it. The requirement: ceiling and underfloor insulation wherever it can reasonably be installed, meeting minimum levels. Wall insulation is not required. The traps are in the details: minimums that vary by climate zone, old insulation that has settled below them, and the difference between having insulation and being able to prove it.

What the minimums look like

Insulation performance is measured as an R-value, and the required minimum depends on where the property is: the coldest climate zone, covering the South Island and the Central Plateau, carries a higher ceiling minimum than the rest of the country. Rather than memorise figures that sit in regulations, treat tenancy.govt.nz as the source for the current numbers and focus on the practical question: does the insulation in this specific ceiling and under this specific floor meet the minimum for this address, today?

Insulation ages

"It was insulated in 2010" is a fact about 2010. Bulk insulation compacts, gets moved by tradespeople, gets soaked by a roof leak and never recovers its performance. The standard cares about present condition, which is why a look in the ceiling space with a tape measure and a camera is worth more than an old certificate alone. Gaps, compression and dampness are what an assessor would look for, you can look first.

Where it genuinely can't go

The rules recognise houses where installation is not reasonably practicable, a flat roof with no cavity, a subfloor with no safe access. Exemptions are narrower than optimism suggests: they generally require that installation is genuinely impracticable, not merely inconvenient, and you should keep evidence of why the exemption applies, ideally a professional's written opinion. Do not self-diagnose an exemption without checking the current rules.

Evidence worth keeping

• The insulation statement from installation or top-up, with product, R-value and coverage.
• Photos of the ceiling space and subfloor, with a tape measure in frame if you can do it safely.
• For any exemption, the professional assessment saying why installation is not practicable.

New tenancy agreements have needed insulation information disclosed for years, and the Healthy Homes compliance statement builds on the same records. Landlords who keep the evidence filed per property sign those statements in minutes rather than weekends.