CARROLL PLANTATION — Cliff Severance is an electrical engineer whose career takes him across the country each year. Legally speaking, he lives in Virginia. But deep in the woods of northeastern Penobscot County is the place he considers his real home — if only for getaways.

With curved walls looming over and around him, large diamond-shaped windows offer views of Bog Brook, the trees and the blue sky. The two airy geodesic domes of his residence are the home of his heart, he says.

“The scene outside those windows changes every day. It’s like having a sort of mosaic in your living room,” Severance said during a telephone interview from Kailua, Hawaii, where he is building flight simulators for the U.S. Marine Corps. “The sun is different, the water is different, the sky — all of those things change. You never know what you are going to see when you look out.”

The 61-year-old Severance has been building the home on 150 acres overlooking Bog Brook during vacations since June 2006. With its 46-foot diameter built atop a one-story foundation and a cupola atop the primary dome, Severance’s vacation home is massive — 4,100 square feet among two 1,600-square-foot basement and first floors, a 900-square-foot third floor and a small cupola atop the primary dome. It has a second dome, 29 feet in diameter, that is its garage.

With its garage and lowest floor incomplete, the home is about 80 percent built. But what is finished is finished very well, indeed.

Given the futuristic nature of geodesic domes, you’d expect the house to have an almost science-fiction feel to it, but the absence of the typical rectangular walls and ceilings and use of natural materials throughout creates the opposite impact. The front doorway section of the home is sandwiched between the two domes like a box between two large balls. The front doorway leads to the main floor, which contains the kitchen, dining and living room, bathroom and front door.

The bathroom and front door areas are like typical dwellings, with a rectangular ceiling and walls overhead. The dome’s impact is most keenly felt in the observatory-like dome area that comprises the dining and living room areas. The flooring is a combination of ceramic and slate tiles. The bathroom floor has river stone flooring. All the countertops are granite or quartz. Sheetrock walls provide splashes of color, privacy and definition to the space.

The interior of the dome is tongue-and-groove cedar interspersed with diamond- and triangular-shaped windows and recessed lighting. The colors are muted wood, brown, tan and white tones. Add it all up, and it has a prevailing nature-feel, with the curved ceiling seeming more like the sky itself than a roof.

The upstairs floor and cupola are horizontally recessed to cover about two-thirds the living room space, with banisters lining the open upstairs floor and staircase, giving anyone who doesn’t like heights an almost vertiginous feeling.

The windows of the cupola at the very top of the primary dome resemble more the portholes to a Sherman tank. They feel small, not expansive, but the view they afford is still striking. A rest and reading area, the cupola will eventually be outfitted with bench pads to make it more comfortable, Severance said.

Standing inside the primary dome, “you don’t feel boxed in. You are enclosed, but it feels like you are wrapped in it instead of in a box,” Severance said. “Whether you turn to the outside or look up, now you have this almost kind of cathedral space that you inhabit.”

Reasons both idealistic and practical propelled Severance and his wife Mary into building the home. Built on a network of struts arranged on great circles, or geodesics, lying on the surface of a sphere, the geodesics intersect to form triangular elements that are very rigid and yet distribute building stress and weight across the entire structure. That makes domes very tough, the only man-made structures whose strength increases proportionally as they increase in size.

The domes also offer lovely natural light and acoustics. Not counting the cupola’s five bay windows, the living area in Severance’s rural Maine vacation home has 15 skylights and 11 other windows.

The domes are both noisier and quieter than a regular home, Severance said. They are quieter in that wind and bad weather outside make less sound in the dome because they flow around its outer rounded surface. They are noisier in that the proliferation of curved surfaces every 7½ feet along the inner dome surface helps sound waves to bounce everywhere inside the place.

“With the way the dome is shaped, you can hear the TV better upstairs than you can hear it in here,” said Thomas Greeley, a construction worker for Galen Hart and Sons, one of the subcontractors helping finish build the home’s flooring and wiring.

Sound waves, Greeley said, are less easily trapped than they would be within rectangular shapes. The sheetrock walls in the five bedrooms and bathrooms mitigate this impact somewhat and provide more privacy, Severance said. Within them, only one of the walls is curved.

Those curved spaces can be a big headache to most contractors, Hart said. The constant angled cuts for the tiling outside and the wood inside the dome creates work only experienced contractors should attempt.

This building job isn’t for everyone though. One of the original granite contractors, an experienced man, took a look at the challenge of cutting countertops around the outer curved edge of the kitchen and living room areas and walked off the job, Hart said.

“This is not a do-it-yourself project,” Hart said.

Hart remembers well his first steps inside the structure. “I thought, wow. This is going to be different.”

Not that the dome is a money trap, but Severance claims he honestly doesn’t know, or want to guess, how much money the dome has cost him. Part of that, he said, is the intermittent nature of the construction and the stops that have occurred because of occasional cash-flow shortages. The Severances also regard the dome as the capstone to their relatively lucrative careers — she is also an electrical engineer, but retired — and haven’t been shy about spending money or taking suggestions that have led to improvements, he said.

“Galen [Hart], he and his crew, are the guys who have done the most recent finish work,” Severance said. “Galen to his credit is not only a great contractor but he also has a great eye for design, what looks good in color and texture. He is usually more fussy than I would be, so I don’t have to worry about it being done well or looking good.”

He hopes the house will be finished by the end of the year and looks forward to settling into it full time in a few years.

“The way I feel when I get there, it’s like it’s a sanctuary. I live such a hectic life. All the time I am around people and issues and traveling,” Severance said, “when I go there, I get this release. I can relax. It is calming.”