However, the latest figures published by the country's Instituto Nacional de Estadistica (INE) revealed property transfers were up by 3.9 per cent in the same 12-month period.
Urban properties in Spain were most sought after by buyers in July, with 86.5 per cent of all sales for assets in towns or cities.
According to recent research released by Tinsa, the value of homes in Spain's major cities declined by 13.4 per cent in the year to August.
This is below the national average, with house prices in Spain as a whole dropping by 11.6 per cent in the past year.
The INE data also showed that the split between new and existing homes remained broadly even, with 48.5 per cent of real estate deals for new dwellings and 51.5 per cent for previously inhabited ones.