> ## Documentation Index
> Fetch the complete documentation index at: https://help.ratemyflat.co.nz/llms.txt
> Use this file to discover all available pages before exploring further.

# How scores are calculated

> How ratemyflat aggregates tenant reviews, documents, and public records into a Healthy Homes Score.

The Healthy Homes Score (HHS) summarises how well a home meets the five Healthy Homes Standards in NZ legislation. Every home on ratemyflat has an overall score and individual scores for each of the standards.

## The five standards

The Ministry of Business, Innovation & Employment (MBIE) sets five standards every rental must meet:

1. **Heating:** Fixed heating sources and their capacity to heat the main living room.
2. **Insulation:** Ceiling and underfloor insulation coverage and quality.
3. **Ventilation:** Working extractor fans in kitchens and bathrooms, and openable windows.
4. **Moisture and drainage:** Efficient drainage, guttering, and ground moisture barriers.
5. **Draught stopping:** No unintentional gaps or holes in walls, ceilings, windows, and doors.

## Data sources

The score is dynamic — it shifts as new information arrives. It's built from three sources:

* **Tenant reviews:** The largest contributor. Current and former tenants provide ratings and detail about life in the home.
* **Verified documents:** Information from official records such as Healthy Homes compliance statements, insulation certificates, and tenancy agreements.
* **Public records:** LINZ (Land Information New Zealand) data, used to identify and map the home accurately.

```mermaid theme={null}
flowchart LR
    subgraph Sources [Data Inputs]
        A[Tenant reviews]
        B[LINZ property data]
        C[Verified documents]
    end

    Sources --> D[Healthy Homes Score]
    D --> E[Score Band]

    subgraph Output [Public Result]
        E --- F[Poor]
        E --- G[Needs improvement]
        E --- H[Good]
    end

    style D fill:#1e293b,color:#fff
    style E fill:#DA2C5F,color:#fff
    style Sources fill:#f8fafc,stroke:#e2e8f0
    style Output fill:#f8fafc,stroke:#e2e8f0
```

## Weighting and verification

Not every contribution counts the same. Verified inputs carry more weight than unverified ones — both for reviews and for documents.

* **Verified reviews carry more weight:** When a tenant proves they lived in the home (e.g. with a tenancy agreement), their review has a larger impact on the score.
* **Recent data matters more:** The score reflects experiences over time, with weight on the current condition of the home.

## Scoring bands

Scores are surfaced as bands rather than raw numbers:

* **Good:** The home likely meets or exceeds the Healthy Homes Standards based on available data.
* **Medium:** Some issues are present, or some standards aren't fully met.
* **Poor:** The home likely fails one or more of the Healthy Homes Standards.

<Warning>
  **What the score isn't**
  A Healthy Homes Score is a guide based on aggregated data — not a substitute for a professional Healthy Homes inspection. Landlord behaviour can change, recent renovations may not yet show, and every tenant's experience of a home is different.
</Warning>

## Contributing to a score

The score gets more accurate as more people contribute.

[Sign up to contribute reviews and verify the homes you've lived in](/tenants/verifying-your-tenancy). Your input helps the next person find a warmer, drier, safer home.