By Jesús Aguado

MADRID, May 14 (Reuters) - The Bank of Spain is carefully calibrating potential restrictions on mortgage lending in Spain so that they improve the resilience of households and banks without pushing rental prices higher, the central bank said on Thursday.

The authority is developing a framework that would allow it to activate macroprudential limits on lending standards to prevent risky borrowing, when needed.

In its semiannual financial stability report, it estimated that these measures would shift part of the housing market from ownership to rental, likely leading to lower house prices. But it warned of knock-on effects on variables such as rental prices, which could rise, undermining the effectiveness of the plan.

Therefore, any such measures should be carefully calibrated, it said.

The review comes as rents have been rising well above inflation, with increases of 10% in 2024 and 5% in 2025, in a housing market with an estimated deficit of around 700,000 homes.

Home prices in real terms rose at an annual rate of 9.7% in 2025, although they remain 14.7% below the peak reached in early 2007, before Spain's real estate bubble burst, prompting a bailout for the banking sector.

Financial Stability Director Daniel Perez Cid told a news briefing the institution had not yet detected any signs pointing towards a real estate bubble, such as excessive credit growth.

While the stock of mortgage loans grew 3.7% year-on-year in the fourth quarter of 2025, marking five consecutive quarters of growth, in real terms it remains far below that of 2000-2008.

In March, new mortgage loans in Spain rose 9.6% year-on-year.

Spanish lenders offer the second-lowest mortgage prices in the euro zone, averaging 2.75% as of March. Their approaches to such lending differ, however. While Santander SAN.MC increased its new mortgage lending in Spain by 44% year-on-year in the first quarter, Bankinter BKT.MC reduced it by 40% in the same period.