Sy Bean / Seattle Times / TNSLego master Alice Finch works on a structure from the comic book “Mouse Guard” by David Petersen. Finch is featured in the recent documentary, “A Lego Brickumentary.”

SEATTLE — Alice Finch’s sculpture of Hogwarts Castle, inspired by the “Harry Potter” books by J.K. Rowling, is vast; shaped like an L, with each arm 13 feet long and 5 feet wide. It’s elaborately detailed — with multicolored bottles in the Potions classroom, mossy leaves bursting out of pots in the greenhouse, tiny framed art along the grand staircase, and even a transparent ghost haunting the Ravenclaw Towers — and it took her a year to construct.

And it’s built entirel out of Legos. About 400,000 pieces, to be precise.

A former middle-school teacher who lives with her family on Mercer Island, Washington, Finch is an AFOL: Adult Fan of Lego. Her Hogwarts “build” — as AFOLs call it — was featured at BrickCon 2012, the annual Seattle-area convention for those who love Lego. It won Best in Show and the People’s Choice award.

The following year, she teamed up with fellow builder David Frank to create Rivendell, a fanciful 200,000-brick depiction of Tolkien’s Elven outpost. The result, so colorful and lush it seems to have organically sprung up from the earth, was also a prizewinner.

Finch, at home in her cozy, crammed-full Lego studio recently (it holds, she thinks, about 2 million bricks, all meticulously sorted by color and size), said that she enjoyed Lego as a child, but didn’t make anything specialized until recent years.

The Hogwarts build grew from reading the Potter books with her son, and from her longtime interest in architecture. Her father was an architect, and Finch said that she’s always looking for architectural details while traveling.

“The difference between a great builder and an amazing builder is the level of detail,” she said.

According to the recent documentary “A Lego Brickumentary” (in which Finch is featured), Lego is “a language more global than English or Windows.” The same Danish company has manufactured the pieces since the 1940s, and generations have grown up with a bag of bricks on hand.

Finch, who moved here in the 1990s from her hometown in Southern California, said that the Seattle area is a thriving one for AFOLs. “It rains a lot,” she said, “and there are a lot of highly educated, eccentric, creative people, which lends itself to Lego.” She’s currently a member of SeaLUG (Seattle Lego Users Group), which has about 150 members, many of whom specialize in such categories as castles, space travel or robotics.

And she’s also part of a smaller local group called ArchLUG, which specializes in Lego architecture and is currently structuring a collaborative build for BrickCon 2015, based on David Petersen’s “Mouse Guard” books about the fantasy adventures of a medieval mouse.

Finch, who teaches Lego camps for children, hopes that her visibility as a Lego master will inspire more girls to get creative with the bricks. When she debuted the Hogwarts build, she said, “people were confused and surprised that a woman had done this.”

Going public with her work, in the film and in public events like BrickCon, wasn’t her original intention. “It’s a creative process that I enjoy doing … not something I do for recognition,” she said, but she knows that her visibility might be inspiring.

“If girls see a woman doing it,” she said, “it plants the seed that they can do it.”

But her favorite Lego buddies are her two sons, Thorin, 11, and Hadrian, 7. “We’re always building together,” she said, calling the pastime “a tremendous bonding experience with my kids.” She and Thorin recently collaborated on a colorful “How to Train Your Dragon”-inspired build, and Hadrian, as a 5-year-old, left his mark on Rivendell.

“He built a railway station in the middle of it, so the elves could come to work,” said Finch. “That was his interaction with Rivendell, his way of inclusion into it and of experiencing it.”

As Finch’s elaborate builds demonstrate, there’s no telling what might happen when you combine a pile of bricks, the gift of space and time and a busily whirring imagination. “Lego is kind of its own language,” Finch said, smiling. “You communicate by building together.”