When selling a condominium, the question most owners wrestle with right up to the end is a single one: when to sell. Price is not decided by the floor plan and the state of maintenance alone. Whether the market as a whole is rising, or has begun to turn down, can change the net proceeds on the very same unit by a wide margin. The instrument that lets you confirm the market's direction with data rather than gut feeling is Japan's Residential Property Price Index (不動産価格指数, fudōsan kakaku shisū). Published monthly by the Ministry of Land, Infrastructure, Transport and Tourism (国土交通省, MLIT), it is, in my view, the first piece of primary-source information any owner thinking about the right time to sell should look at.
If you are reading this from outside Japan, it is worth stating plainly at the outset: this is a Japan-specific public dataset with no exact overseas equivalent, though close cousins exist. In the United States, investors reach for the S&P CoreLogic Case-Shiller Index or the Federal Housing Finance Agency (FHFA) House Price Index; in the United Kingdom, for the Office for National Statistics (ONS) UK House Price Index. Japan's index is built and published by a single national ministry, covers the whole country on one consistent method, and — unusually — breaks residential property into land, detached houses, and condominiums as separate series. Understanding how to read it, and where it should and should not be trusted, is the difference between timing a Japanese condo sale on evidence and timing it on rumor.
Key points of this article
- The Residential Property Price Index is an official price-trend indicator published monthly by MLIT (国土交通省). It shows the direction of the market, not the asking price of any individual unit.
- Residential property is split into "residential (overall) / residential land / detached houses / condominiums (owner-occupied units)," and it is condominiums that have pulled the whole market upward.
- The index is a market-wide average. The fair price of your condominium should be judged by using it together with other indicators — the official land-price survey (地価公示), actual transaction prices, and REINS (レインズ).
- The latest index reading is a provisional figure that gets revised. In practice it is more useful to read the direction — "still rising, stalling, or falling" — than to treat the number itself as fixed.
What the Residential Property Price Index is
The Residential Property Price Index is an official indicator that expresses the movement of real-estate transaction prices as a time series, showing whether the market as a whole is trending up or down. MLIT (国土交通省, Ministry of Land, Infrastructure, Transport and Tourism) compiles it every month from roughly 300,000 real-estate transaction-price records a year. Taking the 2010 average as 100, it expresses how far prices have moved since then in index form. Think of it not as the price of a particular property, but as a tool for measuring "the flow of the river" that is the market. Unlike the US Case-Shiller index, which is anchored to January 2000 = 100 and covers 20 metro areas, Japan's index uses 2010 = 100 and is national — a small difference that matters the moment you try to compare a Tokyo condo trend against a US city.
What it measures, and what it does not
What this index measures is the price trend of the market as a whole. The important thing here is that the index is not an appraisal of your condominium. Even when the index is rising, individual units are valued differently according to location, building age, and state of maintenance. Conversely, even when the index is flat, a scarce unit close to a station can still command an aggressive price. The index shows the "direction of the wind"; the individual appraisal shows "how your own boat moves within that wind." They play different roles. For an overseas buyer, this distinction lands harder than it does for domestic sellers, because you are typically further from day-to-day market chatter — which makes an objective national gauge more valuable, not less.
The hedonic method used to calculate it
The Residential Property Price Index is calculated using a statistical technique called the "hedonic method" (ヘドニック法). This is a method that statistically strips out the differences in each property's conditions — location, floor area, building age — and extracts the pure movement in price alone. For example, it removes an apparent change such as "the average price rose this month because there happened to be many transactions of newer buildings," and instead shows how price moved when conditions are held equal. Precisely because of this, it is less swayed by the shifting mix of units that happen to close in a given month, and is well suited to tracking a trend. This is the same family of technique used by the FHFA and the UK ONS index; unlike a simple median-price series (the kind property portals often headline), a hedonic index will not jump merely because the month's sales skewed toward larger or newer homes.
When and where it is published
The residential index is published monthly, and the commercial real-estate index quarterly, on the MLIT website. The residential price index began trial operation in August 2012 and moved to full operation in March 2015. From the June 2020 release onward, a "seasonally adjusted index" that removes seasonal bias is published alongside it. The latest figures and the historical series can be checked by anyone on MLIT's "Residential Property Price Index" page (国土交通省「不動産価格指数」). One practical note for overseas readers: the primary data is published in Japanese, so treat the figures on that page — not an English summary — as the source of truth, and confirm the reading yourself before acting on it.
Why it can be used to judge the timing of a sale
Because a public body keeps measuring the same way every month, you can follow the market's direction objectively, and as a time series. Real-estate prices, if you rely only on advertising and the talk around you, inevitably drift into impressions — "it feels like prices are rising," "surely we're near the ceiling by now." The index becomes material that either backs up that impression or, conversely, corrects it.
This index was developed amid an international push, triggered by the 2008 global financial crisis, for countries to build out real-estate price statistics. In Japan too, MLIT held repeated sessions of a "study group on developing indicators of real-estate price trends" from fiscal 2010, aligning the framework with internationally shared rules. In other words, it is an indicator designed to withstand not only Japan's temporary domestic circumstances but also international comparison — it follows the same IMF/BIS-linked handbook standards that underpin house-price indices across the OECD. That is exactly what makes it, in my view, highly reliable data, fit to place at the foundation of a decision as large as a sale.
How to "read" the index — the three residential categories and the latest trend
The residential Residential Property Price Index is published broadly in the following categories. If you are selling a condominium, the starting point is to look first at the "condominium (owner-occupied units)" index. Unlike markets where "house price" is quoted as a single national number, Japan deliberately separates land, detached houses, and condos — a structure that rewards the seller who knows which series applies to them.
| Category | What it shows | Use in a condominium sale |
|---|---|---|
| Residential (overall) | Residential land, detached houses, and condominiums combined | Grasp the broad direction of the whole market |
| Residential land | Price trend of land (vacant lots and building sites) | Use as a comparison against detached houses and land |
| Detached houses | Price trend of detached houses | Get a feel for the market of a move-up destination |
| Condominiums (owner-occupied units) | Price trend of condominiums for sale (分譲マンション) | Place at the center of your own sale decision |
Among these four categories, the one that has risen most sharply in recent years is condominiums. As of the time of writing, the latest release that can be confirmed is the December 2025 reading (令和7年12月分, published on 31 March 2026 / 令和8年3月31日公表), in which the seasonally adjusted residential (overall) figure was 148.0 and condominiums (owner-occupied units) was 225.1. Against the base of 2010 = 100, condominiums have reached a level more than double that. Compared with the residential-land and detached-house indices, which have moved in the 110s to 120s, you can see that condominiums alone have risen conspicuously. To put those magnitudes in an international frame: a doubling since 2010 is broadly in the range that hot US and UK metro markets have seen over the same window, so this is a strong run, not a Japan-only anomaly — but read it as a trend, not a guarantee.
That said, these are provisional figures, subject to revision for roughly three months after their first release. Rather than treating the numbers themselves as absolute, it is more useful in practice to read the direction — "is it still rising," "has the pace of increase narrowed and started to stall." At the point when you are considering a sale, please confirm the figure at that moment and the movement over the most recent few months in MLIT's latest press-release material (国土交通省 報道発表資料).
Why you must not judge on the Residential Property Price Index alone
Because the Residential Property Price Index is a market-wide average, and not the fair price of your single unit itself. A sale decision is sharpened by first confirming the "direction of the wind" with the index, and then layering on more property-specific indicators. When I take an owner's consultation, I too make a point of lining up several yardsticks side by side. This multi-source discipline will feel familiar to investors used to triangulating Case-Shiller against Zillow/Redfin comparables in the US, or the ONS index against Rightmove asking-price data in the UK — the Japanese equivalents simply have different names.
| Indicator | Published by | Role / characteristics |
|---|---|---|
| Residential Property Price Index | MLIT / 国土交通省 (monthly) | Market-wide trend. Reads the "direction of the wind" for timing a sale |
| Official land-price survey (地価公示, chika kōji) | MLIT / 国土交通省 (once a year, in March) | Unit land price at standard sites as of 1 January. Confirms the long-term level of land prices |
| Transaction prices (取引価格情報, actual closed prices) | MLIT Real Estate Information Library (不動産情報ライブラリ) | The price bands actually closed. Reveals the real level in the neighborhood |
| Market-trend report | REINS (レインズ, the designated distribution organization) | Recent number of closings, unit price of closings, and change in inventory |
The official land-price survey (地価公示), for instance, is material for confirming the long-term level of land. In the 2026 survey (令和8年 / 2026年 地価公示), the all-use national average was published as up 2.8% year on year, and residential land up 2.1% — a rise for the fifth consecutive year. If the rise in the index and the rise in land prices point in the same direction, you can read the market tailwind as reasonably reliable. On the other hand, the actual asking price is refined toward a more up-to-the-minute reading by looking at recent closing unit prices and inventory changes in the market-trend report of REINS (レインズ, the designated distribution organization / REINS Market Information). REINS is Japan's Realtor-operated closed listing network — closer in spirit to a US-style MLS than to a public portal, and not something an overseas seller can search freely, which is one reason a local agent adds value here. On how to combine these layers, reading how to confirm your home's fair price using AI appraisal alongside this should make the pairing with an individual appraisal easier to picture.
The procedure for judging the timing of a condominium sale
In practice, checking in the following order keeps the judgment from wavering. It is a flow that places the index at the "entrance" and takes corroboration from property-specific information.
| Step | What to do | What to look at |
|---|---|---|
| 1 | Check the most recent 12 months of the condominium (owner-occupied units) index | Which phase it is in — rising, flat, or falling |
| 2 | Compare the national index with the index for your own regional block | Whether your region points the same way as the nation, or has diverged |
| 3 | Check nearby closing prices with the transaction-price information | The real price band of the same building and similarly sized units |
| 4 | Check inventory and closings in the REINS market trend | Whether inventory is rising while closings slow |
| 5 | Reconcile the individual appraisal with your move-up plan | Net proceeds, price of the move-up destination, remaining mortgage balance |
What matters is not to jump in simply because the index is rising. Even in a rising phase, if inventory has suddenly increased, competition among sellers can lengthen the time to close. Conversely, even when the index is flat, a popular area with scarce supply can still settle on favorable terms. Grasp the broad flow with the index, and fine-tune with current inventory and closings. This two-tier approach leads to a sale with fewer regrets. For a way of thinking about the exit that includes structural factors such as inflation and rising construction costs, I have organized this in detail in a real-estate exit strategy for an era of inflation and rising construction costs.
Four cautions when using the index
It is a highly reliable index, but used incorrectly it can mislead the judgment. Conveying the drawbacks honestly, too, is our stance. The following four points are worth keeping in mind.
- Provisional figures get revised: the figure for the latest month is a provisional value, published on the premise that it will be revised for roughly three months after its first release. It is important not to draw conclusions from a small increase or decrease over a single recent month.
- Regional indices swing with sample size: in regions with few transactions, the index can move sharply up and down. For regional or specific-area indices, it is safer to look at the trend over several months than at a single month's movement.
- National and regional indices diverge: it is not unusual for your own region to be flat or falling even while the nation is rising. In a sale decision, please prioritize the index for your own regional block over the national index.
- There is a lag versus closings: because the index is based on transactions that have passed through certain procedures such as registration, it lags the current market by several months. The heat of the very latest moment needs to be supplemented with REINS closing data.
How second-hand condominiums in the Greater Tokyo area have actually moved is also taken up in the latest trends in the Greater Tokyo second-hand condominium market. By moving back and forth between grasping the "plane" that is the index and the "point" that is each area, the resolution of your judgment improves.
INA's view — the number is a tool, the judgment takes a long-term view
The Residential Property Price Index is a highly effective tool for viewing the timing of a sale objectively. But a tool is, in the end, only a tool. I do not recommend the shortsighted use of "the index is high, so sell right now" or "it is low, so sit on it." Is the purpose of the sale a move, a reshuffling of assets, or inheritance planning? The optimal timing changes with that purpose.
We value long-term judgment aligned with the customer's life plan more than the momentary height or lowness of the index. Confirm the market tailwind with the index, layer on the individual appraisal and the funding plan, and on that basis think together about "whether to move now." Sharing the numbers honestly, and conveying both the good sides and the cautions without concealment, is what I believe leads to long-term trust. For an overseas investor, that means we will tell you plainly when the data says wait — even if you were ready to act.
Related reading
FAQ
- Q. Where can I check the Residential Property Price Index?
- On the MLIT (国土交通省) website — the residential index is published monthly and the commercial real-estate index quarterly. Historical movements, regional data, and detailed figures in Excel format are all available free of charge. When considering a sale, please confirm the figure and the recent movement in the latest press-release material. Note that the primary data is published in Japanese.
- Q. When selling a condominium, which index should I look at?
- Within residential property, the "condominium (owner-occupied units)" index is the closest yardstick. On top of that, please check not only the national index but also the index for your own regional block. The nation and your region can move differently.
- Q. Between the national and regional indices, which should I weight more?
- In a sale decision, please prioritize the regional index. Even when the nation is rising, your own region can be flat or falling. Especially when the divergence between the two is large, it is important to confirm the current situation with regional closing cases and the REINS market trend.
- Q. If the index is rising, should I sell straight away?
- A rise is a rough guide to a tailwind, but I do not recommend deciding on that alone. In a phase where inventory has increased and closings have slowed, a sale can take time even while the index is rising. Grasp the broad flow with the index, then judge by layering on inventory, closings, the individual appraisal, and the funding plan.
