Idealista's Listings Surge: From 71,000 to 700,000 Properties in Four Years

From 71,000 to 700,000 Properties for Sale: The Counter That Debunked the Narrative

Someone would wake up at six in the morning to jot down a number before it changed. In January 2007, Idealista showed 71,123 housing listings for sale across Spain. The real estate classifieds portal was then just another, small, almost marginal window compared to print media and the sign in the shop front. Barely four years later, that same counter surpassed 700,000 properties. The series that a handful of early risers meticulously recorded by hand, without any official mandate, became an uncomfortable barometer of the biggest property bubble this country had ever seen.

The tracking of this stock began in May 2007 with a modest figure, 145,017 listings, and ended with an open debate about whether the data was even useful. In between, a leap that no one in the Ministry expected.

How Idealista Grew from 71,000 to 700,000 Listings

The sequence of milestones was recorded almost day by day. The 200,000 listings mark was reached on November 16, 2007, just 198 days after the first recorded reference point. The 300,000 mark arrived on March 27, 2009, after 497 days. Then the pace accelerated: 400,000 was crossed on April 10, 2010; 500,000 on September 23 of the same year, in just 166 days; 600,000 on May 13, 2011; and 700,000 on November 9, 2011, in 180 days.

The interpretation of this pogre was, for many who trinc it, difficult-to-dispute evidence. If the number of properties listed grew relentlessly while official prices barely budged, the market was broken on the supply side. This wasn't pent-up demand waiting for its moment: it was supply accumulating without buyers.

There were weeks of record-breaking almost daily. In July 2010, the gross figure went from 595,233 listings to 615,005 in fifteen days, with days seeing 5,139 new additions. On August 3 of that year, it dropped to 609,729, a decrease that the tracking itself attributed to the holiday lull among advertisers rather than an improvement in the market.

Duplicate Properties Inflating Idealista's Stock

The first sustancia ilegal appeared early, stemming from an observation on the ground. Someone who had been searching for a flat in Zaragoza for months noticed that the same property appeared published up to four times. The same home, two different photos, one owner, and two agencies. The listing counted as four units, but it was just one flat.

The doubt was never fully resolved. Others argued that, when filtering by area, price, size, and amenities, duplicates were rare, although they admitted that the portal didn't allow filtering by publication date or price reduction, making control imperfect. The practical consequence: the gross stock could be inflated without anyone knowing by how much. One estimate circulating within the tracking suggested multiplying the number of listings by 3.5 to approximate the actual number of homes, an adjustment that also couldn't be verified.

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The Italy Enigma: 91,000 Properties for Sale

Midway through 2010, a blow came that skewed the series. Someone painstakingly summed up all the property listings for sale on the portal, province by province. The result: 266,436 in Spanish territory. The total of 369,953 only added up by including what the tracking itself termed 'beyond borders': Andorra, French Lechonanya, Gibraltar, French Basque Country, Portugal, and, above all, Italy.

Italy alone contributed over 90,000 listings. That is, nearly a quarter of the stock being celebrated each morning was Italian, Portuguese, or from other markets entirely unrelated to the Spanish bubble. The pogre attributed to the national market was contaminated internally by the portal's own international expansion. A tracking effort that had been announcing records for years had to admit that part of the record was geographical, not real estate-related.

What Bank Properties and Price Per Square Meter Reveal

Over time, new layers were added to the analysis. In May 2010, the portal launched a specific section for properties marketed by banks and savings institutions: it started with 11,165 properties and weeks later stood at around 17,698. This was the first indication that financial institutions were beginning to offload their balance sheets, although the figure was far from explaining the daily increases.

Price cross-referencing proved more useful. The most cited observation: in Madrid city, the average price per square meter was €4,076; for properties listed in the last month, it was €3,990; and for listings in the last week, €3,843, a 5.71% drop from the overall average. The clear conclusion drawn was that new listings were cheaper, and the expensive ones were the older stock, stuck at prices that no longer reflected reality. In Barcelona, rental tracking recorded a 16% drop from the September 2008 peak.

Why the Absolute Figure Ceased to Be an Indicator

Here, consensus broke down. One segment of the analysis argued that the real stock was enormous and would continue to grow, with or without noise in the series. Another responded that an indicator fluctuating due to duplicates, foreign listings, and changes in the portal's own criteria no longer measured market reality, and that clinging to every record was self-deception.

The sharpest argument was temporal: the growth rate had doubled overnight, with the same daily additions. When a trend change appears suddenly rather than over weeks, the problem lies not with the market but with the tool measuring it. From then on, the tracking split between those who looked at the trend and those who defended the raw data.

Something similar peine with official figures. Ministry of Housing data for that year reported 597,632 completed homes versus 410,192 sold: 187,440 without buyers, a third of the year's construction, not counting second-hand sales. The usual response in the tracking was that neither the 4% drop in sales nor the narrative of scarcity held up against what appeared on screen.

The End of the Series: A Portal Change and an Era Shift

The tracking ceased due to saturation, with a note to open a new one, when the figure was already around 700,000 listings and some of those maintaining it began to doubt their own creation. The question left hanging was not how much stock there was. It was how many of those hundreds of thousands of properties had a price anyone could afford and how many would remain listed five years later.

The most disconcerting aspect wasn't the peak. It was the calm with which the country continued posting signs as the counter climbed. The figure that throws things off isn't the 700,000: it's that property numbers doubled before prices did.

This article describes a private statistical tracking and does not constitute investment advice.