The greenhouse effect has gotten a bad rap in the press since the United Nations declared its restrictive War on Carbon. A greenhouse is also called a hothouse. Its purpose is to let in light, convert it to heat, and trap it inside so plants can grow when it is much colder outside.
A greenhouse is called a “forcing structure” because it is an artificially-created environment which “forces” plants within it to grow. The greenhouse effect is what happens when sunlight passes through transparent or translucent materials such as glass or plastic, strikes opaque surfaces inside (such as plant leaves, containers, and the greenhouse floors and benches), and changes some of the light energy into heat.
The darker the surface inside the greenhouse, the more heat is generated. Greenhouse panels are designed to transmit light but not heat so most of the heat stays inside the structure.
So far, so good. But a Swedish couple took a good idea and made it brilliant when they encased their whole house in a mostly-transparent greenhouse. It’s true.
In 2015, Marie Granmar and Charles Sacilotto moved their young son into what has got to be one of the most eco-friendly homes on the planet. The Stockholm family wanted to shut out the chilly winter winds from a summer house they bought and came up with their “Naturhus” – Nature House, a greenhouse built with 4-millimeter panes of glass that cost about $84,000 to install.
Granmar explained why she and her husband decided to clad their dwelling inside another structure:
“This was a summer house. It was not really made for year-round living. But that was also part of the idea, that you could actually put this greenhouse around the summer house and actually live in it with nice comfort all year ’round.”
Sunlight helps warm the home during the day. Bedrock below the house stores residual heat for release during the nights. With January temperatures near or below freezing, the rooftop deck is a great place to sunbathe, read or hang out with junior – year-round. The couple removed the roof that came with the summer house and made it over into a family-friendly recreational area, complete with swings and bikes.
“The greenhouse is the big thing here: to save your own energy and energy from the sun – to use that heat in a natural way, not being too cold in the winter, even in the Nordic climate.”
Sweden is located at a high latitude in the Northern Hemisphere, near the Arctic Circle at a distance of only about 500 miles. Periodic blasts of ice-cold air that come out of the Arctic or Siberia alternate with warmer Atlantic currents. The Naturhaus takes the worry away from any and all frightful weather outside.
Because the interior summer house is never exposed to rain or weathering elements, the bare wood siding only needs to be coated with linseed oil. Very little insulation is needed since the house is heated by the greenhouse a few feet away. Home repair expenses inside the protective shell stay low and make spending money to upgrade the home’s appearance cost-effective.
Granmar and Sacilotto help out the planet by capturing rainwater for household use and by composting kitchen and garden waste. Speaking of waste, engineer Sacilotto constructed the sewage system which “begins with a urine-separating toilet and uses centrifuges, cisterns, grow beds and garden ponds to filter the water and compost the remains.”
The greenhouse extends the perimeter of the house, almost doubling the residential footprint. The wrap-around garden yields fresh tomatoes, cucumbers, grapes, herbs, and even figs – all veggies that wouldn’t stand a chance outside the greenhouse walls.
Architect Bengt Warne designed and built the first Naturhus between 1974-76. The forward-thinking innovator described his concept:
“The core, a living area, is surrounded by a shell of glass – a greenhouse. Nature’s own flows and cycle of exploitation is used. The elements earth, water, air, and fire can be used to maintain the house.”
Sacilotto, Warne’s protégé, found his inspiration in that work:
“It’s not just to use the nature, the sun, and the water, but… it’s all a philosophy of life, to live in another world, in fact.”
Warne had promoted the idea that a house within a greenhouse added an extra dimension to human life:
“Living in a greenhouse gives architecture a fourth dimension, where time is represented by movements of naturally recycled endless flows of growth, sun, rain, wind, and soil in plants, energy, air, water, and earth. I call this NATUREHOUSING.”
Warne’s environmentally responsible house-inside-a-greenhouse took every possible life support factor into account:
- Mull earth is produced in a room below the toilet.
- Kitchen and garden waste is composted as well.
- Rainwater is collected, used for bathe, dishes, and laundry and then returned to nature as irrigation and nutrition.
- The plants clean the air and enrich it.
- A high-efficiency stove is able to keep the house warm in times of extreme cold.
- The sun drives the air around the living area and the heat from the greenhouse is stored in the bedrock below the house.
- The Nature House is a sun collector area to live in and the major idea is to return to nature what is taken from it.
A few other visionary pioneers have built greenhouses around their homes elsewhere in Sweden and Germany. Only time will tell if Americans will embrace this trend from across the Big Pond.