In our March 2016 issue, we visit a 1959 home in Portland designed by local architect William Fletcher that was converted into a modern, comfortable residence for a family. We spoke to interior designer Jessica Helgerson, whose firm worked with architect Dale Farr to reimagine the house, to glean her tips for updating a midcentury home without sacrificing its history.

1. Think subtle-but-functional.

"We try to be very sensitive to the buildings we’re working within, not to create slavish recreations of the past that don’t function," Helgerson says. "We do not want the house to look like it was remodeled in 2014. Our ideal goal is that the house looks like no one’s ever done anything to it."

2. Go for the open plan.

"The midcentury was a beginning of a movement towards a more open plan, but it didn’t quite get there," Helgerson explains. "From a remodeling perspective, it’s something we see and wrestle with. The kitchen has come even more out of hiding in the last half century. We see quite a few half walls, the kitchen is peeking out a little bit, but the cook is still hidden." Helgerson says that most clients who choose a modern house want a modern lifestyle, and that means that creating an open-plan arrangement and eliminating the walls around the kitchen.

3. Be thoughtful with materials.

Helgerson says that in the midcentury period, there were less material choices than we have now, so it's important to be considerate of that. For tile, she swears by Heath and Ann Sacks. She says that marble and granite usually don't fit in a midcentury space, but travertine and natural wood do.

4. Consider a structure's particular history.

Not all midcentury modern architecture is created equal. Helgerson draws a distinction between "personality-laden gems" and more typical ranch houses. "The ranch house is more forgiving, and it can be more playful," she says, whereas renovating one-of-a-kind, architect-designed dwellings requires more sensitivity to the original design program.

5) Go easy on the lighting.

Helgerson's firm often uses track lighting to complement the sloped wood ceilings of midcentury structures. "Lighting feels like it needs to be of the era, nothing tremendously fancy," she says. "It's more about simple shapes that respond to the simple shapes of the architecture."