Opinion piece.
The same thing happens to me every week. I call a landlord whose tenant is leaving and ask if we should let the flat again. More and more often, the answer is no: they'd rather sell it or simply leave it empty until they decide. On the other end, the phone rings with tenants who have been looking for a rental for months and have decided to try buying instead.
This is the experience of one firm, not a statistic. But the data points the same way, and I think it's worth explaining why it's happening.
The rental market is closing
Since 16 March 2024, Barcelona and most large municipalities in Catalonia have applied the rent containment rules of Law 12/2023: a new contract can't exceed the rent of the previous one and, if the landlord is a large holder or the flat hasn't been let for five years, it can't exceed the reference index either.
The Catalan Government argues it's working, and it has one figure on its side: the average rent on new contracts in Barcelona in the first quarter of 2026 was 4.7 % lower than two years earlier. I don't dispute that. The problem is how many contracts are being signed.
According to the tenancy deposits lodged with Incasòl, 132,988 rental contracts were signed in Catalonia in 2023, 118,626 in 2024 and 108,057 in 2025. In the city of Barcelona, 30,789 last year, compared with 32,903 the year before. And the figure that worries me most is the net balance, the difference between contracts signed and contracts ending: in Barcelona it was over 9,000 in 2021 and 2022, fell to around 6,500 in 2023, to 2,700 in 2024 and to barely 500 in 2025. The rental stock has practically stopped growing.
When there are fewer flats, the ones that come up are fought over. Idealista estimates that each rental listing in Barcelona receives around 95 enquiries, more than twice as many as in Madrid. A lower price is little use if you can't get a contract signed.
Why landlords are pulling out
The landlords we work with aren't investment funds. They're mostly individuals with one, two or three flats. For them the calculation is simple: if at the end of the contract they have to lower the rent, accept extensions they don't control and a regime that changes every few months, selling at record prices is a reasonable way out. This very year, the Spanish Government approved a decree in March that capped rent increases at 2 % and let tenants extend for two years, and Congress threw it out weeks later. That instability weighs as much as the rules themselves.
Every flat that leaves the rental market and is sold turns a potential tenant into one more buyer, and a landlord into a seller. Demand doesn't disappear. It moves to another market.
New builds aren't coming
A tenant who decides to buy looks at new builds first. In Barcelona there are hardly any.
In September 2018, the City Council approved the amendment to the Metropolitan General Plan requiring 30 % of new-build developments and major refurbishments of over 600 m² to be set aside as social housing. It's often called the "Colau law", although it isn't a law but a planning amendment. The intention was good: to create affordable housing with private money.
Eight years later, according to figures released by the City Council itself, the measure has produced 34 flats. The council estimates that, along the way, more than 2,000 affordable homes have failed to materialise. The current mayor tried to relax it and this summer announced that the reform has been shelved for lack of agreement.
What I see is what hasn't been done. Small and medium-sized developers, the ones who used to buy an old building, refurbish it completely and put it back on the market as renovated homes, have stopped doing so in Barcelona, because with a compulsory share at a social housing price the numbers don't work. Many of those buildings are still there, unrefurbished, and those homes don't exist.
All the pressure falls on the resale market
If the rental market is closing and new builds aren't coming, there's only one place left to look: the resale flat. That's where the person buying a home to live in, the tenant who can no longer find a rental and the investor who used to buy to let all end up.
The result shows in prices: according to idealista, homes for sale in Barcelona were going for €5,440/m² in August, 6.3 % more than a year earlier. And the biggest rises aren't in l'Eixample (+4.2 %), but in Nou Barris (+15.9 %) and Sant Andreu (+12.2 %). The pressure is moving down to the neighbourhoods where people who were renting until yesterday are now buying.
This has been tried before
Berlin froze rents in February 2020. Advertised rents fell, but supply collapsed: the ifo Institute estimated that advertised rental flats fell by as much as 60 %, and they didn't recover after Germany's Federal Constitutional Court struck the law down in April 2021. A study published in Management Science concludes that some of those flats appear to have been permanently lost to the rental market.
Since 2016, Ireland has capped rent increases in the highest-pressure areas, Dublin included; in recent years at 2 % a year. In 2025 the Government itself acknowledged that the system had held back investment and supply, and since March 2026 it has allowed rents to be reset to market levels between tenancies and has exempted new developments from the cap.
I'm not saying caps don't lower rents. They do, for people who already have a contract. What experience shows is that, if there are no more homes, a cap shares out the shortage instead of solving it, and leaves out newcomers: the young person leaving home, the person moving for work, the person going through a separation.
What I would do
I don't have a magic solution, but I do have a few certainties from the firm. Refurbishing buildings in Barcelona needs to pay off again, and that means revising the 30 % rule so it can actually be met, for example on another plot in the same neighbourhood. We need stability: people letting a flat need to know what the rules will be in five years' time. And the authorities need to build and release their own land at the pace they promise.
In the meantime, if you have a flat and you're torn between letting it again or selling it, do the sums with the real rules, not those of the listing next door. We'll help you do them. And if you're looking for a home and have switched to buying, make sure someone checks the flat you find before you sign.
Sources: Institut Català del Sòl (tenancy deposits) and Government of Catalonia; idealista (August 2026); Barcelona City Council, via Metrópoli Abierta (August 2026); ifo Institut (2022); Hahn, Kholodilin, Waltl and Fongoni, Management Science (2024); Government of Ireland (June 2025).
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