Some policies also include a buffer or allowance to meet the current building standards and codes. EG bushfire zone ratings, cyclone wind loadings etc.
These do change over time, typically adding requirements which can add cost to a repair or rebuild.
EG
Notable issues have arisen in recent years where councils/building regulations have required the whole of a partially damaged property to be upgraded to the latest. The trigger has typically been based on the proportion of the dwelling or floor plan area. The total cost to the insurer increases out of proportion to the damage.
