Question juridique clé
Whether the costs of glazing an open seating area qualify as deductible energy-saving maintenance expenses for direct federal tax.
Solution extraite
No. The taxpayers did not prove that the glazing was an energy-saving measure, and objectively it primarily expanded living space rather than saving energy.
Motifs extraits
The FHNW report was only marketing-oriented documentation and did not substantiate an actual energy-saving effect. The taxpayers bore the burden of proof and failed to provide further technical evidence. The installation covered only a small part of the facade and windows, making its main purpose residential expansion.