HomesEstimate
An estimated value for an individual home.
Calculated from recent sales and public data, it’s a starting point in determining a home’s value and is not a formal valuation. The HomesEstimate is calculated fortnightly.
The HomesEstimate is our estimated market value, computed using a proprietary formula. It is not a formal valuation. It is a starting point in determining a home's value. The HomesEstimate is calculated from public data, registered valuer's valuations, and real estate agents' comparative market analyses (CMA). For a formal valuation your real estate agent or registered valuer physically inspects the home and takes special features, location and market conditions into account.
We encourage buyers, sellers and homeowners to supplement the information provided here by doing other research such as:
- Getting a comparative market analysis (CMA) from a real estate agent. You can request a free appraisal on Trade Me here.
- Getting a formal valuation report from a professional property valuer
- Visiting the house (whenever possible)
- Getting a building inspection carried out
- Obtaining the local council Land Information Memorandum (LIM) report
- You may want to visit other open homes in the area and/or take note of nearby sale prices to get a feel for property prices in the area
Our HomesEstimate is an automated, computer-generated estimate of what we think a home may sell for—it is not an official valuation. It uses publicly available data from local councils, such as sales of similar properties, Capital Valuation (CV), and property details (e.g. bedrooms and bathrooms). If the data we get from these sources is inaccurate or incomplete, our estimate is likely to be less accurate as a result. We cannot manually adjust the estimate or the property data we receive from councils, but there are some steps you can take yourself—see below.
What can I do if my estimate looks wrong?
- You can upload a full market registered valuation report completed by a registered valuer.
- You need to ‘track’ your property on homes.co.nz first, which you can do by clicking “I own this home”, and then clicking “Update this HomesEstimate”.
- Contact a licensed real estate agent and request a property appraisal. Once an appraisal has been completed, the agent can then log into their Homes account to update your property’s estimate—they will need your permission (as the homeowner) to submit their appraisal to the homeowners estimate calculations, and they must complete the appraisal in accordance with the REA guidelines.
- If you don’t have a preferred local agent, we encourage you to use our handy appraisal request tool on Trade Me: https://www.trademe.co.nz/a/property/request-an-appraisal.
We always encourage deferring to your local real estate agents or registered valuers for their expertise as they will have a better knowledge of your property and the local area.
My property details are incorrect, can I update them?
The property details we hold about a property are from council records. These can be incomplete or inaccurate at times, particularly if they become outdated.
We cannot change the data we get from councils, but we encourage you to contact your local council if you wish to have their records updated.
In January 2025, we released significant updates to our HomesEstimate algorithm to make it, in the majority of cases, more stable and more accurate. The new algorithm makes use of AI to better deal with areas with lower data availability. We’ve also included more home characteristics (like house size, number of bathrooms etc) to help the algorithm make more robust predictions by using more data points. While results may vary depending on the specifics of a property, and the quality and quantity of data available to us, the updates to our HomesEstimate algorithm should improve the accuracy of estimates (when compared to actual sale price) in most cases.
Note - Properties listed ‘for sale’ prior to 28 January 2025 are under a ‘grace period’ and will continue to use the estimates calculated by our prior algorithm in order to avoid potential disruption to their active marketing campaigns. The grace period will end on 17 March 2025, at which time estimates for all properties will be provided by the updated algorithm.
We use proprietary automated valuation models that apply advanced AI algorithms to analyze our data, to identify relationships between home-related data and actual sales prices. Home characteristics such as house size, location or the number of bathrooms are given different weights according to their influence on home sale prices over a specific period of time. This results in an AI model that generates each home's HomesEstimate. Specifically, some of the data we use in this algorithm include:
Property attributes:
Location, land area, house size, number of bedrooms, bathrooms, decade built and many other details.
Rates assessments:
Property rates information and other information provided by the local council records.
Prior and current transactions:
Actual sale prices over time of the home itself and comparable recent sales of nearby homes.
Agent's appraisals:
When available, market appraisals provided to us by real estate agents are incorporated in the model to improve estimates for those properties.
The HomesEstimate's accuracy depends on the availability and accuracy of council and sales data in a particular area. Below is a table showing the accuracy of the HomesEstimates in comparison to subsequent sales values throughout the last three months.
| Median Error | Within 10% | Within 20% | |
|---|---|---|---|
| Christchurch | 5.22% | 75.00% | 93.39% |
| Selwyn District | 3.20% | 88.95% | 98.84% |
| Palmerston North City | 5.06% | 79.22% | 93.51% |
| Auckland | 5.51% | 72.09% | 92.20% |
| Hutt City | 5.95% | 69.62% | 91.14% |
| Western Bay Of Plenty District | 6.57% | 73.13% | 94.03% |
| Waimakariri District | 3.62% | 82.73% | 94.24% |
| Thames-Coromandel District | 8.29% | 58.25% | 84.47% |
| Whangarei District | 5.33% | 68.94% | 84.09% |
| Far North District | 10.59% | 47.62% | 77.14% |
| Upper Hutt City | 7.05% | 69.23% | 92.31% |
| Whanganui District | 9.00% | 53.93% | 89.89% |
| New Plymouth District | 6.20% | 75.32% | 94.16% |
| Queenstown Lakes District | 8.04% | 61.60% | 92.00% |
| Napier City | 5.16% | 86.89% | 98.36% |
| Waikato District | 5.38% | 69.11% | 91.87% |
| Kapiti Coast District | 5.97% | 77.50% | 95.83% |
| Tauranga City | 4.12% | 80.29% | 97.08% |
| Southland District | 7.06% | 69.49% | 93.22% |
| South Waikato District | 9.27% | 51.52% | 100.00% |
| Ashburton District | 5.67% | 85.14% | 97.30% |
| Dunedin City | 7.13% | 63.93% | 88.11% |
| Wellington | 5.98% | 73.54% | 94.55% |
| Marlborough District | 5.09% | 71.43% | 86.67% |
| Tasman District | 4.72% | 80.46% | 94.25% |
| Hastings District | 5.68% | 72.73% | 94.95% |
| Waipa District | 5.26% | 75.45% | 95.45% |
| Taupo District | 8.21% | 66.67% | 85.96% |
| Central Otago District | 5.93% | 70.49% | 91.80% |
| Grey District | 7.27% | 60.00% | 90.00% |
| Invercargill City | 5.95% | 73.33% | 93.33% |
| Masterton District | 6.97% | 66.04% | 86.79% |
| Hauraki District | 7.27% | 70.00% | 96.67% |
| Hamilton City | 4.63% | 84.47% | 96.12% |
| Porirua City | 5.78% | 84.38% | 95.31% |
| Horowhenua District | 6.83% | 64.29% | 88.10% |
| Hurunui District | 6.74% | 73.33% | 93.33% |
| Buller District | 6.50% | 61.90% | 85.71% |
| Kaipara District | 6.83% | 65.63% | 96.88% |
| Timaru District | 6.49% | 71.01% | 92.75% |
| Waimate District | 7.40% | 57.14% | 100.00% |
| Nelson City | 5.60% | 84.95% | 95.70% |
| South Wairarapa District | 4.70% | 57.14% | 100.00% |
| Manawatu District | 6.62% | 74.47% | 93.62% |
| Rotorua District | 5.47% | 78.95% | 97.37% |
| Carterton District | 5.46% | 82.35% | 100.00% |
| Gisborne District | 9.55% | 52.73% | 92.73% |
| Waitaki District | 7.71% | 64.29% | 90.48% |
| Otorohanga District | 8.03% | 66.67% | 88.89% |
| Clutha District | 7.33% | 64.52% | 83.87% |
| Whakatane District | 5.86% | 76.92% | 88.46% |
| South Taranaki District | 7.54% | 60.42% | 97.92% |
| Opotiki District | 10.47% | 40.00% | 100.00% |
| Central Hawke's Bay District | 9.93% | 51.85% | 77.78% |
| Tararua District | 6.20% | 72.73% | 86.36% |
| Westland District | 8.72% | 62.50% | 93.75% |
| Rangitikei District | 6.87% | 59.38% | 87.50% |
| Waitomo District | 8.03% | 66.67% | 88.89% |
| Matamata-Piako District | 4.18% | 78.57% | 96.43% |
| Mackenzie District | 8.94% | 64.71% | 88.24% |
| Gore District | 10.42% | 40.00% | 100.00% |
| Kaikoura District | 2.28% | 83.33% | 100.00% |
| Wairoa District | 8.98% | 61.54% | 100.00% |
| Ruapehu District | 10.37% | 42.86% | 78.57% |
| Kawerau District | 4.43% | 71.43% | 100.00% |
Median Error:
The median percentage difference between the price that a property sells for and the HomesEstimate at the time of sale.
Within 10% of Sale Price:
This is the percentage of transactions in a region for which the HomesEstimate fell within 10% of the subsequent sales price.
Within 20% of Sale Price:
This is the percentage of transactions in a region for which the HomesEstimate fell within 20% of the subsequent sales price.
Example:
A property with a HomesEstimate of $630,000 recently sold for $670 000. In this case the difference between the two values is 5.97% ([$670,000-$630,000]/$670,000) which means it falls within category "HomesEstimate within 10%"
Note: These percentages are calculated by comparing each sales transaction occurring in the last 3 months with the HomesEstimate we published immediately before that sale occurred.
We typically refresh the HomesEstimate for all homes once a fortnight. We may also refresh the HomesEstimate for particular properties earlier than this, in the event there is a change in the information we have about those properties.
The HomesEstimate for a property can also change when the property sells, a real estate agent provides a market appraisal, or a homeowner provides a valuation from a registered valuer. Updating the HomesEstimate in this way is a unique service that homes.co.nz offers. Homes.co.nz acknowledges that an algorithm is unlikely to be as accurate as a physical inspection so we defer to the industry experts when we can to provide the most up-to-date and accurate estimates of a property's value. Any agents providing a market appraisal do so in accordance with the REA guidelines, including ensuring any appraisals realistically reflect current market conditions.
The HomesEstimate is a starting point in figuring out the true value of a house. The amount of data we have for the house affects the HomesEstimate accuracy.
Price history and property facts:
Check to see if your price history (the sale price and date you bought your home) and property details (house size, land area and age of construction) are correct on homes.co.nz. Depending on the area in which you live, this can be a big factor in your HomesEstimate.
Updates and renovations explained:
Most upgrade information is not in the public records and is not easily quantifiable. We do not know about home updates and renovations unless they have been reported to your local council, so those are not used in HomesEstimate calculations. There is no way for us to systematically gather and verify the type of remodel or build information where the value is based upon how the final product appeals to the buyer. Because of this, the algorithm can't use that information.
There are a number of reasons why the HomesEstimate might be quite different from your current Capital Value (sometimes referred to as Rateable Value or Rating Value). These include:
- Capital Values are calculated at quite long intervals, usually every three years. The HomesEstimate is re-calculated every two weeks. In your case, the market values for your area might have moved a long way from the last Capital Value.
- Your house may be quite different from the typical house in your area (significantly larger/smaller house, views, newer/older). In this case automated valuation models like the Capital Value and HomesEstimate can struggle to get an accurate estimate of the market value for a property capturing its unique situation.
- Your property may have been substantially altered since the last Capital Value (e.g. an extra bedroom added, a new garage built, or a piece of land sub-divided off the section). If this alternation has been correctly captured in the council records, the HomesEstimate will reflect the alteration, but the Capital Value won’t necessarily until the next round of general assessments.
- The information in your council record may be incorrect (i.e. wrong house size, number of bedrooms or type of construction).
No. The HomesEstimate is not a formal valuation and you won't be able to use it in place of a valuation. It is a computer-generated estimate of the worth of a house today, given the available data. homes.co.nz does not offer the HomesEstimate as the basis for any specific real-estate-related financial transaction. Our data sources may be incomplete or incorrect; also, we have not physically inspected a specific home. Remember, the HomesEstimate is simply a starting point and does not consider all the market intricacies that can determine the actual price a house will sell for.