I read this book in the mid-2000s, maybe 2006?, in the USA. It was in English, and it was a paperback middle-grade chapter book, maybe 200 pages long.
The main character is a girl who learns to build fairy houses from someone significant in her life, maybe an aunt, cousin, neighbor, or friend. At some point in the story, this person leaves.
Over the course of the story, the girl spends more and more time outside building fairy houses. It's implied (or maybe stated outright, I forget) that she spends so much time outside to escape a bad situation at home. At some point, I think she waits on a stoop for a long time, though I forget what she was waiting for.
At the end of the book, the girl walks outside without a weather-appropriate article of clothing (maybe a jacket or shoes), and she remarks that fairies don't feel the cold. It's suggested that she is/is becoming/is associating herself with the fairies.
I seem to remember it being misty and cool a lot in the book. It took place in the modern era, in the real world, in a suburban or urban neighborhood setting. When reading it, I remember being unsure if the fairies actually existed or if the girl just wanted to believe in them.
When I search for book about fairy houses, most results are light-hearted and cute. This book had a more serious tone, although it wasn't very dark or disturbing.
