How to make spells permanent?

[slachance6]

There are several spells that would make sense to have a permanent variant, such as Transform Object and Alter Visage (which even says "1 hour unless made permanent" for its duration). Am I missing some kind of casting rule or advantage that allows spells to be made permanent? If not, what is a balanced homebrew option? This would probably only be allowed to be added to harmful or environmental spells, as permanent buff spells would be overpowered.

[Bruno]

Generally it's listed under the cost, as in the case of Alter Visage, or it's an enchantment (under the Item section).

[Anaraxes]

Use the enchantment rules. Both Alter Visage and Transform Object have an energy cost specified. "Any item" could just as well be the subject of the spell. Add enough Power to cover the maintenance of the spell, and then treat it as an "always on" item (Magic p19).