Jackie Chase calls it "the invasion."

That's the moment her two grandsons, ages 3 and 1½, burst inside her back door, jump astride the plastic cars parked in her mudroom and start racing up and down the hand-scraped walnut floors in her newly built house in Mendota Heights.

Chase couldn't be happier about the commotion. And those new walnut floors? They're tough enough to take the beating. Like most everything in Chase's new home, they were planned with grandkids in mind.

Becoming a grandmother was what prompted Chase and her husband, Mike, to build their house in the first place. "What changed was grandchildren," said Jackie. The couple's previous home in Sunfish Lake, which they'd built to their specifications a decade earlier, was designed for adults.

"There was no place to run. It was not a house for kids," she said. "As you start having grandchildren, you don't want them to go downstairs and play in the basement. You want to be involved."

Downsizing was off the table. "Everybody my age is moving to a condo," said Jackie, 62, who recently retired from a career in employment law and human resources and is now starting a consulting business.

Building a big house as a new retiree isn't the norm, she acknowledged, "but I've cautioned people my age not to downsize too much. Once you have grandchildren, you want places that work for them — where they can slam doors and throw things on the floor. ... It's all about your stage of life and embracing that."

Chase isn't the only empty nester who is rethinking the condo-in-retirement template, said her builder, Scott Santanni, owner of Santanni Custom Homes. "More people will be doing this," he predicted, building next-stage houses rather than downsizing to condos. "They still want a little garden, a little plot of grass, some individuality."

Chase wanted not just a grandkid-friendly house but also a grandkid-friendly yard. "I have a lot of dreams of having these kids come here and run freely, do fun things, cool things at Grandma's house," she said.

So the Chases started looking at building sites. Realtor Paul Dorn told Jackie about a property that wasn't on the market yet but would soon be coming up for sale in Mendota Heights. The private, 1½-acre lot was at the dead-end of a quiet street and had its own sledding hill. The rolling, wooded setting reminded Jackie of Dubuque, Iowa, where she grew up. "I thought, 'Wow!' This could be a good grandma site.' "

There was a 1950s house on the lot, but because of a platting mistake years earlier, the house was encroaching on a neighbor's land, which had resulted in a legal dispute. The Chases ended up buying the property, with plans to tear down the nonconforming house and replace it with a new one.

One of the most challenging aspects of the Chases' project was siting the house on the lot, Santanni said. Despite its large size, its proximity to the Mississippi River came with caveats. "There wasn't much wiggle room, because of the bluff lines and high-water marks."

Santanni and the Chases tried different configurations, using a scale drawing of the lot and a paper model of the structure until they found the bull's-eye location, tucked at an angle at the end of a long driveway. "This is the only spot it would work," Jackie said.

Timeless look

Jackie, who assembled a ring binder with color-coded tabs for everything from lighting to appliances, is an admittedly "compulsive" client who knows what she wants.

For this house, what she wanted was a timeless look, including a big front porch and a deepest blue/almost black exterior with crisp white trim. "I was going for classic, like a navy blue blazer with white pants — Cape Cod, preppy," she said.

Santanni initially thought the dark hue was a mistake. "I was nervous about the exterior color," he said. "I thought it was too dark, too bold. But I grew to love it."

Inside, the floor plan is open with a farmhouse-style kitchen that flows into the adjacent dining area, designed to accommodate both grown-up dinner parties and casual family dining with the grandsons. The kitchen is light and bright — white subway tile, marble countertops, simple white cabinetry and a farm sink in front of a big window overlooking the rolling backyard.

The kitchen also was designed with an eye to aging in place. The microwave is located inside a drawer with an automatic door. "It's so much easier if you have a big pot and need to stir," Jackie said. The two-drawer dishwasher accommodates large and small loads. "It's really efficient for a couple."

The Chases' main floor also includes a living room finished with shiplap siding and a stone fireplace; a three-season porch with a big-screen TV, durable ipe wood flooring, a two-sided fireplace and a window system that converts to screens; a small office off the kitchen, and dual owner's suites.

Upstairs, there's a large guest room with window seats and a bathroom for the boys, plus a "nice, big bonus room" that Jackie turned into a toy-filled playroom.

Downstairs, the lower level offers 2,400 square feet of unfinished space. "It's a great space for little kids. They can go ride bikes down there," she said.

The big backyard that reminded Jackie of her childhood now includes a generous lawn for playing, a handcrafted pergola designed by Santanni, a patio, dining area and a firepit — with an eye to backyard cookouts when the boys are a bit older. "We already roasted marshmallows over the firepit," Jackie said.

In the meantime, she enjoys visits with her grandsons several times a week. Sometimes her daughter, Rachel, the boys' mother, comes along, and sometimes Jackie babysits, although she enjoys it more when she's not outnumbered. "I've babysat a few times by myself, and it's crazy-making. My husband and I can divide and conquer."

Despite months of wear and tear from little hands, little feet and little plastic cars, the house still looks pristine enough to have appeared on the recent Artisan Home Tour.

"It's worn well," Jackie said. "It turns from a lovely custom-built home into Grandma's house. It's just really fun — and really gratifying."