Why Ancient Buildings Seem Indestructible

Walk through the streets of Rome, and you will see stone aqueducts, arches, and temples that have stood for over two thousand years. Visit a historic European village, and you will find churches and cottages from the 15th century.

This leads many to declare: “They don’t build things like they used to. Older buildings were built to last, whereas modern buildings fall apart in a few decades.”

This sentiment is a classic example of structural survivorship bias.

The illusion of ancient quality

When we look at historical architecture, our sample set is heavily biased. We only see the buildings that have survived natural disasters, wars, decay, and urban redevelopment. Because these survivors are exceptionally strong, we mistakenly assume that all historical construction was of the same quality.

In reality, building quality in ancient times was highly unequal:

• The Roman aqueducts and temples were built using massive budgets, the finest volcanic concrete, and the absolute best engineers of the empire. They were built for emperors and gods, and they were actively maintained for centuries.
• The vast majority of Roman citizens lived in poorly constructed wooden tenements called insulae. These buildings collapsed frequently, caught fire constantly, and disintegrated into dust within a generation.

The shoddy construction of the past has long since disappeared, leaving only the structural masterpieces for us to observe today.

Why modern buildings seem “worse”

Modern architecture is subject to a different set of economic and structural requirements:

• We build millions of structures every year, from fast-food restaurants to suburban homes, designed for short-to-medium-term utility (e.g., 30–50 years) before they are replaced or remodeled.
• Because we see these temporary structures age and get demolished in real-time, we compare them to the top 0.01% of ancient structures that survived for millennia.
• In addition, modern building codes, safety factors, and materials (like reinforced concrete) are mathematically far more durable and safer than typical historical methods. We simply build many more buildings that aren’t intended to stand for 2,000 years.

Key takeaway

Comparing the best survivors of the past to the average of the present creates a false sense of decline. The builders of the past did not possess lost secrets of indestructible concrete; they simply built a lot of fragile things that broke, and a few exceptionally strong things that didn’t.