This is far from a clear cut yes or no answer and depends upon other factors like how and where the gold is stored in the house.
Gold's melting point is at 1064°C. Silver's is at 961.8°C.
Whereas the average house fire burns at around 600°C.
So at a glance it looks like both silver and gold should survive the “average” house fire.
However with some research we also found statistics that said “the maximum temperature of a fully developed building fire will rarely exceed 1800°F [982°C]”. So in the right circumstances (available combustibles, ventilation conditions, properties of the compartment enclosure, weather conditions, etc) the maximum temperature a building fire could reach is just above the melt point of silver and getting close to gold.
Gold and silver both have a high melting point that should be higher than just a standard house fire temperature.
But if your gold and silver bullion was in some kind of packaging as many coins are, then obviously this would melt and could damage the exterior.
Also consider that it may be difficult to dig through the ashes to even find your bullion after a major fire.
While your gold and silver may still be “pure” after a fire, if the bullion is damaged then when the time comes to sell you will likely receive less for it. It will need to be refined again and re-cast or -reminted and assayed. So a gold buyer or refiner will likely offer you much less than the prevailing spot price of gold or silver for it because of this.
However there is a downside to fire resistant safes. They are much easier to break into.
Fire resistant safes are built completely differently. Their walls are made out of light gauge steel with a “fibre mat” filler. Understand this is more about insulation from heat than attack resistance. They also have vents in the back to let heat escape. So all in all they are much easier to break into as they are built to withstand high temperatures not attack.
However many attack resistant safes will still provide some protection against fire even when they don’t have a fire rating. There is historical evidence whereby money held inside safes have survived fires in commercial buildings here in New Zealand.
So for storage of gold and silver consider attack resistance first, fire rating is secondary, but a bonus if you can get it. Why?
Because there is a greater risk of theft than of a house fire.
See this article for more on the topic of safes:
Buying a Home Safe for Gold Silver Storage
Also as our reader pointed out, consider what else you have in your safe with your bullion. If you have articles that are combustible at much lower temperatures, then these might contaminate or damage your bullion too.
But their condition will depend on how exactly they are stored.
Consider a safe for added protection from fire not to mention from theft.
Or other storage options with lower risk of fire could include a private vault (see here for more information on them). Or maybe some “midnight gardening”. That is bury it!
Whatever you choose there is no 100% foolproof option so it may not be a bad idea to spread your eggs across more than one storage option.