Doctrine by topic · DGT Observatory
How the DGT's position on this topic has evolved, and the rulings it rests on.
Current position
For the deduction for energy rehabilitation works (paragraph 3), amounts exceeding the maximum annual base of 5,000 euros may be deducted in the following four tax years, with an accumulated base limit of 15,000 euros. However, for deductions for the reduction of heating/cooling demand or improvement of primary energy consumption (paragraphs 1 and 2), the excess of the annual limits cannot be deducted in subsequent tax years. The deduction is applied in the period in which the amounts are paid, regardless of when the energy efficiency certificate is issued.
The DGT maintains a clear distinction between the different paragraphs of the deduction. While for paragraph 3 it allows the carryover of the excess base to future tax years with an accumulated limit, for paragraphs 1 and 2 it expressly prohibits such carryover. The doctrine has remained constant in this technical differentiation.
Turning points
Clarifies that for paragraphs 1 and 2, the regulations do not allow the carryover of the excess base to subsequent tax years, unlike paragraph 3.
Analysis based on 13 of 15 rulings with a stated position. Updated 26 September 2026.