Building Materials

All building materials used in Sesseljuhus are desirable inclusions in environmental terms.  Emphasis was placed on the use of renewable energy and environmentally sound treatment of effluent.  We took into account the sources, production methods and end of life recovery capabilities of the materials. 


Most studies indicate that timber is the most environmentally friendly building material publicly available.  Lumber is derived from a renewable resource and is the result of solar energy.  In addition, trees produce oxygen using carbon dioxide, CO2, from the atmosphere.  There is not much pollution or energy consumption associated with the use of timber.

However, not all wood used is considered environmentally friendly.  This is for two main reasons.  First, you need to take into account where the timber comes from because it must be from renewable forests to be considered environmentally friendly.  A renewable forest is one in which new trees are planted in correlation with the logging.  Second, you need to consider how the timber is treated.  Most pesticides and varnishes are very toxic, but there are safer alternatives that do not harm the environment.

Wood as a building material possesses excellent properties.  Its tensile strength is high and it is flexible.  The structure of Sesseljuhus is mostly made of wood and its walls are clad with it.  Laminated timber was also used in Sesseljuhus.  The benefits of this are many, as laminated timber uses parts of trees that would otherwise not be usable (small section timber) and laminated timber can span large distances.  The glue used in the manufacture of laminated timber can be troublesome, but the glue used for our material does not contain much formaldehyde, so there is minimal need for concern.

The timber in Sesseljuhus was from BYKO and the laminated timber from the Límtré company.



Most paints contain solvents.  Solvents, as their name suggests, are dissolved by transpiration.  This causes the paint to offgas as it dries after it has been applied.  The escaping solvent compounds are released into the air that people breathe.

In Iceland, little is known about the use of organic paints.  Organic paints contain natural solvents, unlike oil-based and water-based paints which are both bad in terms of pollution during their production.  Organic paints give off far fewer solvents after application and, unlike oil-based and water-based paints, will break down naturally in the wild.

All paints used in Sesseljuhus are from the Livos company, which has for years manufactured products derived from 100% natural ingredients.

Þ.Þorgrímsson imports Livos products to Iceland

Wool Insulation

It does not take much work to convince people of the excellence of Icelandic wool when it comes to clothing and blankets.  The wool is warm and retains its warmth even if it gets wet.  To insulate a house with sheep wool, however, is not common and people know much less about that.  It is usually obvious when ideas are foreign, but not so in this case as the first person to use sheep wool to insulate a house was an immigrant to Iceland named George Hollanders.

The Ístex company supplied Icelandic sheep wool for insulating the floors and walls of Sesseljuhus.  A total of 3,870 kg of wool was used, the equivalent of 2,400 sheep.  Flecked wool was used as its insulation value is equal, but white wool was reserved for traditional woolen good production as its appearance is more desirable.

The wool required a little preparation for use as insulation.  First it was washed in 45o C water with a detergent similar to baking soda.  The soda has the natural ability to turn into soap when it comes into contact with the fat in the wool.  The wool was then washed twice with another environmentally friendly soap and dried.  Before the wool was carded, it was cooked in a high pressure pot with a mixture of Borax and saltwater, which wards off insect and rodent infestation.  The mineral Borax has for many centuries been used to preserve timber.  According to the U.S. Forest Service, Borax is harmless to man and animals, so it can be safely included in fertilizers.  Beyond these functions, the Borax also increases the fire resistance in wool to help meet current safety standards in Europe.  The wool was finally carded, combed, debugged, rolled up, and packed into canvas bags.  Using this method, we obtained a 100% natural insulation material that requires no protective equipment for handling.

The insulation value of wool is similar to that of drywall, but if moisture gets in, sheep wool insulation has a great advantage.  Sheep wool has the natural ability to absorb up to 1/3 of its own weight in moisture without losing its insulation value.  Wool can also unload its moisture when the air is dry, thus helping to keep the humidity within the building balanced.  Likewise, it can also take in condensed moisture from the air to make it drier.

Another major advantage of wool is that the energy that goes into the production of wool insulation is negligible in comparison to that of most other insulation materials.  Recent studies have also shown that keratin, a substance found in wool, removes hazardous materials from the air including formaldehyde, ozone, and various solvents found in most modern construction projects.  Because of these characteristics, wool is increasingly used overseas to improve the interior air quality of public buildings formerly causing illness (sick-building syndrome), including hospitals, daycare facilities and schools.


Paper Insulation

For the roof of Sesseljuhus, paper insulation was used.  The backbone of paper insulation is cellulose, or tree and plant fiber.  Paper insulation is composed of recycled materials, being manufactured from surplus stock of newspapers, books and phone books.  The scrap paper is shredded and then treated with Borax in the same way as the sheep wool.  The result is a material with a high insulation value and fire resistance requiring little energy to produce as it is composed of materials that would otherwise be discarded.  The product is then compressed into bales or bundles to simplify transport and increase efficiency.

Paper insulation is placed in the insulation cavities of buildings with the help of blasting machines which free installers from the hassle of rotating and cutting sheets.  The material is blown through a long line, not unlike a vacuum cleaner in reverse, which guides the material to its destination, the ceiling and parts of the walls in the case of Sesseljuhus.

There is a separate hose to get air into the machine, the nozzle for which was closed after the cavities were filled with the paper insulation.    The walls were filled with insulation as well before disconnecting this line.  Paper insulation can also be used to insulate floors, but wool was used in Sesseljuhus.  A part of the building was also insulated with a combination of sheep wool, paper and flax.

Electrical Wiring and Lighting

wiringWe designed and selected the electrical equipment in Sesseljuhus in an effort to be environmentally friendly, i.e. it was a rule to use natural materials with low energy production, to utilize alternative energies, and that components be mostly recyclable.  Conduit and cables were installed to minimize run distances and thus the amounts of substances used while innovative wooden cable trays enabled exposed runs for ease of maintenance and demonstration purposes, but they almost take on a decorative function as well.

Lamps were selected primarily with energy efficiency in mind, but also with consideration for the convenience of the occupants of Sesseljuhus.  Light distribution is easily adaptable to a variety of usage patterns in the building.  The electrical contractors were from the Selfoss company Fossraf and the conduit materials were obtained from the company Smith and Norland as well as GH Wholesale.

Sesseljuhus is the first modern building in Iceland that is 100% free of polyvinylchloride (PVC).  PVC is considered environmentally-harmful, as it requires a lot of energy for its production and it is composed of non-renewable resources including oil and gas.  In addition, it cannot be recycled, nor does it break down naturally after its useful lifetime and its contents can be harmful to human health.  Emissions from the material are believed to cause cancer, respiratory diseases and skin diseases.  Burning PVC gives off lethal compounds.


driftwoodSesseljuhus is completely clad in Icelandic driftwood collected from the shore of Ströndum.  Facing the building with driftwood is the most environmentally friendly means available as it is a natural material and is utilizing a material that would otherwise be lost.  Also, with its time in the ocean, the wood is salt-saturated, making it very durable and eliminating the need for further protective finishes.

The wood is believed to have arrived here from the shores of Siberia, most likely from the large Ob, Jenisej, Katanga and Lena rivers.  Endemic northeast surface currents carried the wood across the ocean, tossing it about before washing it ashore.  It drifted from Siberia north until it became frozen within ice near the North Pole for about five years.  In the northern seas, the timber was finally released from the ice and battled with the winds and currents to get to land.  After this long trip, the wood was cured by the saltwater and thereby gained natural protection against the elements.  Driftwood often has such a journey and therefore makes for excellent structural timber as well.

Most of the driftwood found in Iceland is pine or larch, but there is also a little spruce and poplar.  It is believed to travel 400 to 1,000 km per year.  The northern beaches of Iceland are sometimes “white” with wood, but it can also sink before reaching shore.  The oldest trees, according to their growth rings, are up to 500 years old.

Úlfar Eyjólfsson from Krossnesi and Sigursteinn Sveinbjörnsson from Litlu-Árvík installed the driftwood cladding.

Wood Preservation

More often than not, wood finishes are made from toxic compounds.  Among the active compounds in wood varnishes are PCP and other substances designed to kill organisms and plants that can live in timber.  Because of these toxic properties, such materials can also be harmful to humans through the disruption of genetic alleles or enzyme activities.

In 1998, a law was passed regulating its domestic use and certain chemicals were forbidden for use in wood finishes.  Accordingly, it is not allowed to import, sell or use any wood finishes that contain mercury, arsenic or high amounts of certain other toxic compounds.  It is also illegal to import, sell, distribute or recycle wood treated with these materials.

Environmentally-harmful wood finishes also give off toxic fumes when burned.  The ash produced during combustion is highly toxic and requires much care in its disposal.  Since the active substances in wood finishes are not water-soluble, a solvent is generally used that has adverse effects on the environment and mankind with its emissions.  Unfortunately, though, few studies have been made into fixing these two harmful aspects of wood finishes.

In Sesseljuhus, the wood on the interior is treated with a vegetable oil from the German company Livos, which has specialized in making environmentally-friendly paints for over 25 years.  Livos products bear the stamp of the European Union, certifying that their manufacturing process is environmentally-friendly since they only use organic solvents.


There were four types of flooring selected for use in Sesseljuhus.

  1. Linoleum floor coverings from the Dutch company Forbo, which are composed of only natural substances and are certified as environmentally-friendly products; Fyrirtækið Kjaran is the company that imports Forbo products to Iceland.
  2. Recycled rubber tire flooring from the rubber processing plant in Akureyri
  3. Icelandic dolerite slabs by Steinsmiðja S. Helgasonar
  4. Wood parquet of Icelandic larch from Guttormslundi in Hallormsstaðarskógi planted in 1936;  The larch flooring was prepared by Húsavík-Harðviður and is the first flooring they have made with only Icelandic timber





Sólheimar sjálfbært samfélag | 801 selfoss | Iceland | Sími: 422 6000 |