Short answer. No. Article 299 of the Revised Penal Code says that if the robbery is committed in one of the dependencies of an inhabited house, the penalties next lower in degree than those prescribed for the house itself shall be imposed. A garage or shed attached to the house is treated as a dependency, not as the house itself.
What the law says
Any armed person who shall commit robbery in an inhabited house or public building or edifice devoted to religious worship, shall be punished by reclusion temporal, if the value of the property taken shall exceed Fifty thousand pesos (₱50,000)
Revised Penal Code, Article 299 — Robbery In An Inhabited House. Read the full provision →
What the law says
If the robbery be committed in one of the dependencies of an inhabited house, public building, or building dedicated to religious worship, the penalties next lower in degree than those prescribed in this article shall be imposed.
Revised Penal Code, Article 299 — Robbery In An Inhabited House. Read the full provision →
The baseline penalty is for the house itself
Article 299 sets its penalties around robbery committed inside the inhabited house, public building, or place of worship itself. Any armed person who shall commit robbery in an inhabited house or public building or edifice devoted to religious worship, shall be punished by reclusion temporal, if the value of the property taken shall exceed Fifty thousand pesos (₱50,000). That figure, and the penalties tied to it elsewhere in the article, are what apply when the robbery happens inside the main structure.
Dependencies get a lower penalty, expressly
Article 299 answers your question directly in its closing sentence: If the robbery be committed in one of the dependencies of an inhabited house, public building, or building dedicated to religious worship, the penalties next lower in degree than those prescribed in this article shall be imposed. A structure that is a dependency of the house, rather than the house itself, is punished one degree lower than the penalties the article otherwise prescribes.
Why a garage or attached shed fits the dependency rule
A garage or shed physically attached to the house, but not part of the house's own living quarters, is the kind of structure the dependency rule addresses — accessory to the main house rather than the house itself. Because Article 299 treats dependencies differently by name, robbing that space is not automatically punished exactly as if the robbery had occurred inside the house's own rooms.
Reading the peso figures correctly
The Fifty thousand pesos figure in the text above reflects Article 299 as amended by Republic Act No. 10951 in 2017, which revised property values throughout the Revised Penal Code. Older reproductions of the Code still print the much lower 1930 amounts, so any source you check should be read against the current, amended figures rather than the original ones.