City Spiders Are Larger
Many animals do better when they live alongside humans. One seldom thinks of spiders though. If you travel overseas you soon discover the huge spiders in rented accommodation. Research has shown that these frightening but usually friendly creatures do grow larger in warm homes.
They don't have to be living inside the houses either. Just staying close to warm building is sufficient. The golden orb spider was placed in particular external environment and data were collected. Those near buildings were larger and fatter than their bush cousins. Living in the middle of a car park with the heat given off by cars made them bigger as well.
Though many people fear them, urban spiders are harmless. They keep pest insects in check. If they weren't there, we would probably be "eaten alive" by flies and gnats. Rather than spraying and crushing them, put them outside and send them on their way.