FAIRVIEW TWP — A sustainable rustic-chic retreat, a hobbit house with heated floors and an earthy abode with mud walls insulated by alpaca wool are just some of the 15 miniature sustainable houses built by teams of environmental science students at Karns City Area Jr./Sr. High School.

Kurt Crosbie, environmental science teacher, said 33 students in 15 teams spent the last two months designing and building sustainable-themed model houses that highlight environmentally friendly ideas and concepts.

On Friday, the students showcased their houses while faculty and staff judged them to select top finishers.

One well-appointed and environmentally friendly home was the five-room rustic-chic house built by seniors Cayley Craig, Haylie Karenbauer and Ava Fox.

The house was built of bamboo and wood, and decorations on the walls included a picture of the girls in their Karns City varsity volleyball uniforms.

Every feature of the house was carefully considered with sustainability in mind.

“We even stained the wood with water-based, eco-friendly stain,” Haylie said.

The two-story house features a spiral staircase made of a tree, which the girls said was the home’s first feature and the one the rest of the house was built around.

A water wheel powered by rainwater recharged batteries that pumped the water to a greenhouse.

“If you have water available, why not use it?” said Haylie. “Why let it go to waste?”

“We can save money by collecting rainwater and using it to water our plants,” Ava said. “Then we can grow our own food and save even more.”

A tiny chicken coop with eggs inside and a fenced-in area for the chickens, a compost bin on the house’s roof, and a vegetable garden rounded up the exterior features of the house.

The inside was well-decorated and included area rugs woven from old T-shirts, furniture built from leftover building material, a solar powered fan and a bathroom, complete with extra toilet paper.

“We focused on aesthetics as well as efficiency because we wanted it to look pretty,” Haylie said.

The girls have not decided what to do with the house now that the project is over.

“We said we wanted to Airbnb it,” Cayley joked.

The girls said the project was very educational.

“I didn’t know straw could be used as insulation for a house,” Cayley said.

“I learned what (materials) would not deteriorate and could be used in real-life situations,” Haylie said.

“I didn’t realize we could re-use water so much,” Ava said.

The team of Landon Wilson, Brennan Harmon and Taylour King wanted something unique and different, so they created a hobbit house.

The roof, which was covered in real grass planted in dirt, represented ground level, with the single-story living space being underground.

The team kept furnishings to a minimum because houses being sold are normally empty of furniture, fixtures and other aesthetics, Landon said.

A windmill powered the strip of efficient LED lights along the living space’s ceiling. Almost everything used to build the house was recycled, including the wood floors and walls, which were sourced from Landon’s uncle’s cutting board shop.

Taylour said the hobbit house’s original design looked good on paper, but did not work out well in actuality.

“I learned we shouldn’t dive into something head first,” she said. “We had to redo the whole design.”

The house built by juniors Zachary Mansberger and Eric Anthony sported a slanted roof to direct rainwater to a system that conveyed it to the plants in the greenhouse.

An empty Monster energy drink can served as a wood stove, and a fan powered by batteries blew the heat downward so it wouldn’t remain trapped in the house’s high ceiling.

The boys took a minimalist approach when building the house.

“It’s pretty easy to build a sustainable house,” Zachary said. “You don’t need that much stuff.”

“People have way too much stuff,” Eric said.

Seniors Trevin Henry and Brady Boyle built a cabin made of saplings harvested by Trevin. The “logs” were joined with modeling clay to keep out the cold winter wind.

The boys made a woodburner from an old aerosol can that contains an ingenious system to make it perfect for heating or cooking.

The woodburner serves another purpose as well.

“It’s a furnace and at the same time heats up water for the in-floor heating,” Trevin said.

The team of seniors Emily Foringer and Adrian Brothers and junior Kaelyn McCollim created a two-story, five-room house with many sustainable systems and features, including real plants and live moss inside and outside.

An outdoor garden and indoor plant room fed by natural light provides vegetables for the home’s theoretic occupants.

“We don’t really have to rely on the supermarket,” Adrian said.

The external walls are made of dried mud insulated with alpaca wool, solar panels power a few lights and appliances, rain from the grass roof is caught in a barrel for use by occupants, and a highly insulated refrigerator keeps perishables cool without using much electricity.

“And there’s lots of houseplants to purify the indoor air,” Adrian said.

Crosbie said the sustainable house project is in its third year at Karns City Jr./Sr. High.

“Every year they outdo themselves and raise the bar even higher,” he said.

Crosbie said he hopes the students involved take away one main lesson.

“I hope the students have a better appreciation of how they can make the planet a better place through cost-saving measures that are environmentally friendly,” he said. “I also hope they learn they can make things happen if they work together and put their minds to it.”