Three months into living in her new Habitat For Humanity house on Willett Way in East Falmouth, Sharon Morais, 44, can hardly believe it is hers.

“It still hasn’t sunk in,” said Ms. Morais, standing in her sparkling clean kitchen on Saturday,. “I play house and then at the end of the day I realize it’s my house.”

Ms. Morais is originally from Carver and grew up vacationing with her family in Mashpee. In 2013 Ms. Morais and her two children—Jack, now 16, and Sophia, now 13—were sleeping on the floor in Ms. Morais’s brother’s basement. The family then moved into a two-bedroom, 750-square-foot apartment in Mashpee.

Jack and Sophia shared a bedroom in the Mashpee apartment. But as the siblings got older, Ms. Morais decided they needed more space.

Ms. Morais, who is a hostess at the 99 Restaurant in Mashpee, then tried to buy a house, but she did not make enough money. Someone then recommended she apply for housing through Habitat For Humanity.

Ms. Morais got started by applying for a new Habitat build on Willett Way. It was 2021, and the application had a strict March 13 deadline. She recalled working on the paperwork on her birthday, earlier that month, to ensure the application would be mailed and received in time.

The application was long and detailed. She had to undergo a credit check and a criminal background check, and had to provide six months of bank statements and all her W-2s. She did a Zoom interview with Habitat For Humanity of Cape Cod employees.

“You have to be able to check a lot of boxes,” Ms. Morais said.

Then came the months of waiting, which was difficult, Ms. Morais said. But on a day in August 2021, she got a call from Habitat.

The employee told Ms. Morais to come to the Habitat office in Yarmouth to sign some paperwork for her application. When she got there, an employee showed her into a room where five women were waiting. They started congratulating her, and someone handed her flowers. At first Ms. Morais was confused—who were these women congratulating?

When she realized it was her, and that she was being congratulated for winning the housing lottery, she started crying.

Ms. Morais still remembers the weather that day. It was pouring rain.

A few months later, in late 2021, construction on Ms. Morais’s house on Willett Way started. Her house is in a neighborhood with half a dozen or so other Habitat houses soon to be owned by single moms.

On December 4, 2021, the house got its walls.

“Me and my son and my daughter and about 50 other people put the wall up behind you,” Ms. Morais said, gesturing toward the living room wall.

Habitat home winners have to put in 250 sweat equity hours per adult in their household. They can complete those hours by working on the construction site, working at a Habitat ReStore, volunteering at events, and bringing in friends and family to volunteer. Ms. Morais finished her sweat equity hours in 11 months.

Construction took longer than expected, largely due to COVID-19, Ms. Morais said. Her last day on the construction site was April 8. She moved in on April 22.

During those 16 months of construction Ms. Morais used a nail gun for the first time, learned how to shingle a house, faced her fear of heights and built close relationships with the Habitat volunteers and the other soon-to-be homeowners on Willett Way.

“It already feels like a community,” she said.

With the house at 1,200 square feet, three bedrooms and 1½ baths, Ms. Morais’s daughter now has her own bedroom for the first time ever. Ms. Morais has her own yard, sun porch, solar panels on the roof and the biggest closet she has ever had.

The house is valued at $300,000, she said, but her purchase price was $168,000. The cost is offset by sponsorships through local faith organizations, including the Cape Cod Synagogue, Saint Barnabas’s Episcopal Church and Waquoit Congregational Church.

Ms. Morais will pay a mortgage, but at a more affordable rate than if she had bought a house at market value. (She said the exact mortgage rate is still being calculated.)

The house is deed-restricted as affordable in perpetuity and cannot be sold to a family making above 80 percent of the area median income. Barnstable County’s area medium income is $124,300.

Even after completing her sweat equity hours, Ms. Morais volunteers around the build. She helps shingle her neighbors’ houses and brings snacks to the construction workers (last weekend she brought popsicles).

Since its founding in 1988, Habitat For Humanity of Cape Cod has built homes in all 15 towns on the Cape, amounting to 180 homes, according to the organization’s website.

Currently, in addition to the Willett Way build, Habitat For Humanity of Cape Cod is working on two builds in Sandwich and one in Chatham. The organization aims to have the last of the houses on Willett Way done by the start of the school year.

A faith-based group, Habitat For Humanity of Cape Cod receives much of its funding from donations from individuals, churches, businesses, civic groups and community preservation grants. Much of the labor and material is donated by local contractors. Habitat also accepts government funding as long as the money comes with “no conditions that would violate our principles or limit our ability to proclaim our Christian identity,” the Habitat For Humanity website says.

Ms. Morais’s house is one of 125 resident-owned properties in Falmouth that are deed-restricted as affordable in perpetuity.

According to data from the Department of Housing and Community Development, the town has a total of 1,178 affordable housing units (most of which are rentals), which constitutes 7.9 percent of Falmouth’s total housing stock.

When 10 percent of a town’s total housing stock is affordable, the town is no longer subject to a state law, Chapter 40B, which allows developers to bypass local zoning laws, such as density and height restrictions, if 25 percent of a project’s units are affordable. Once over the 10 percent threshold, towns may still use Chapter 40B by choice to promote affordable housing.