The cottage where Winnie lives is described as "touch-me-not," meaning that it's very neat, clean, and organized. This forms a marked contrast to the Tucks' place, which is more ramshackle, but still quite homely and cosy all the same.
The contrast between the two cottages symbolizes the different worlds that Winnie's family and the Tucks inhabit. As the Tucks are immortal, they don't have to make their mark on the world; they have no need to show off to others and make an impression as Winnie's family and many other mortals do. The "touch-me-not" appearance of Winnie's cottage is an outward expression of her family's social respectability, specifically designed to send a message to the world as to what kind of people live inside. The Tucks, however, are free from such societal pressures and can concentrate on making a warm, cosy home life for themselves, far away from prying eyes.