Kontio log buildings have a modest carbon footprint. Did you know that timber walls are a great way to keep carbon dioxide out of the atmosphere?

Are you concerned about the state of our planet and eager to know what you can do about climate change? In discussions of these problems, there has been a lot of talk about traffic emissions and vegetarianism, but much less about housing. However, housing accounts for almost 30 per cent of the European carbon footprint. Emissions don’t care about national borders. By opting for a Kontio log home, you’ll be doing a lot for the environment, with little effort.

The European Union is committed to reducing greenhouse gas emissions by 40 per cent from 1990 levels by 2030. And we at Kontio are part of this struggle for a healthier planet.

“We have been part of the battle against climate change since the 1970s, which is when we began manufacturing log products. In addition to log houses being an eco-friendly choice in their own right, we handle the whole production chain, from processing the felled logs to the completed houses. We have systematically developed ways to make our products increasingly energy-efficient and environmentally friendly”, says Kontio’s business director Jonas Lindeman.

Log homes are proven to have very good indoor air, which contributes to better health. This is a well-known reason for choosing a log home. It’s worth keeping in mind that healthy choices are also often environmentally friendly. More and more of our customers are telling us they decided on a Kontio log home out of concern for the environment.

What is it about log houses that makes them such an eco-friendly choice? For one thing, they’re built to last and last. A log house will stand firm and healthy from generation to generation, unlike some other types of building. And because log houses are built to withstand the test of time, less maintenance and repair are needed. This saves materials and energy, making log homes easy on the environment while at the same time saving homeowners money and hassle. When a log home comes to the end of its lifespan, the logs can be reused for other building purposes or burned for energy.

A second reason why log homes are such a winning choice for the environment is that timber absorbs energy from the atmosphere in warm weather and releases it in colder weather. For this reason, the logs help cool the house in the summer heat, and heat it in the wintertime. This greatly reduces heating and cooling needs.

Most important of all, the walls of a log house make a very effective carbon sink. In other words, the walls store more atmospheric carbon dioxide than was released into the atmosphere during construction of the building.

Out of the atmosphere, into the walls

What is a carbon sink, exactly? As is well known, the greenhouse effect is the result of excess amounts of certain gases, including carbon dioxide, entering the atmosphere. Since the introduction of fossil fuels, massive amounts of carbon dioxide have been released into the atmosphere. The burning of oil and coal began to release carbon dioxide into the atmosphere from the age-old carbon reserves in the ground.

One cure for this worrying condition can be found in the plant kingdom. Plants absorb carbon dioxide from the atmosphere, binding the carbon within their cells in the form of carbohydrates. When a plant rots or burns, it releases carbon back into the atmosphere, whereas new growing plants bind more carbon. Trees are excellent carbon sinks, because they bind carbon for decades or even centuries before decaying and releasing it back into the atmosphere.

In a log house, then, atmospheric carbon is safely stored within the walls. And because log walls are solid wood, they hold an especially large amount of carbon. Not only that, but the long-lasting nature of log homes means that it will be a long time before that carbon is released.

“For their entire lifespan, the walls of a log house store carbon and keep it out of the atmosphere, even for hundreds of years”, says Tapio Anttonen, the director of Kontio’s log house factory.

For example, over the last ten years up to 650,000 tonnes of carbon dioxide have been bound in Kontio log buildings. This is equivalent to the amount of carbon dioxide emitted in 8,200 jumbo jet flights around the world. Around 25 tonnes of carbon dioxide are bound in the outside walls of a detached house of 180 square metres in area. Only a tenth of this amount–about 2.5 tonnes–is emitted in manufacturing the house and maintaining it for 50 years. The bottom line is that log buildings are seriously powerful carbon sinks–and seriously underestimated ones at that.

More and more people choose their car based on its carbon footprint. Doesn’t it make sense to follow the same principle with your house? Kontio log buildings leave a small carbon footprint. We intend to lead by example, so from now on we will be displaying the carbon footprint of each of our housing products. In other words, we will be providing details of the positive aspects of each of our products from the environmental point of view: how much carbon the building binds, and how the materials can be recycled or used for energy later.

Better for forests

The more that wood is used for building, the better it is for the environment. Whereas wood is a renewable and constantly growing material, the amount of sand needed for cement, for example, is rapidly dwindling worldwide. The 2014 report by the United Nations Environment Programme describes how the sand that is accessible on the surface of the Earth is often not suitable for construction, and how suitable sand needs to be excavated, for example from the bottoms of waterways. This harms marine and river ecosystems, and significantly alters the terrain.

Kontio takes a sustainable approach to wood construction: new forest has to be planted in place of felled timber. The pine used in Kontio products comes from pine forests near the company’s factory. In our wood procurement, we follow a certification system that ensures that the timber come from sustainably managed forests.

“We always know exactly where the logs come from”, says Anttonen.

The latest Finnish forest inventory shows that the growth of Finnish forests is accelerating even faster than was previously known. That means that carbon sinks are growing at an increasing pace–and in Finland, forests grow even faster than they can be felled. For example, the school buildings built a few years ago for 800 pupils in the town of Pudasjärvi in the northern Ostrobothnian region of Finland, were built with the same amount of timber that grows in Finnish forests every 15 minutes or so. Kontio delivered the logs for the project, which began in 2014 and was completed in 2016. However, that forests do not remain carbon sinks forever, even if they are never cut. As Anttonen points out, as old trees in unmanaged forest begin to decay and disintegrate they release carbon back into nature’s carbon cycle.

“Old forests can release as much carbon as they bind”, Anttonen continues.

Waste not, want not

The entire production chain of Kontio’s products is ecologically sustainable. Compared to the amount of energy consumed in transforming wood from standing trees into log homes, over 1.5 times as much energy is generated in the overall process. The felled logs are transported to the sawmill, sawn, dried and further processed. This results in various kinds of logging waste, such as cutter shavings and sawdust, which are collected for use as bioenergy. Nothing ends up on the landfill.

“Kontio uses only about half of the energy produced from side streams for heating and generating electricity”, Anttonen says.

The more energy is generated by burning wood, the less need there will be to burn fossil fuels, which are the major cause of climate change. Fossil fuels release new carbon into the atmosphere from the Earth’s ancient carbon reserves, whereas the use of wood for energy circulates carbon that is already in the atmosphere.

Sustainable = ecological

Sustainable development means that we keep future generations in mind when making our choices. Kontio’s log buildings stand strong for decades, and are also highly resistant to extreme climatic conditions. According to Kontio planning manager Mikko Löf, this exceptional durability is due to the fact that timber adapts well to fluctuations in both temperature and humidity. In addition, log houses are particularly robust structures, standing up remarkably well in areas that have been hit by extreme wind and even hurricanes.

“Timber is a hygroscopic material, meaning that it can evenly absorb moisture from the air and release it back into the air. The structure of log walls is also simple, with no airtight coatings to trap moisture. Because of this, humidity cannot easily condense at any point in the timber, and so moisture damage can be avoided”, says Löf.

And because moisture damage is not an issue, energy-consuming and expensive repairs can also be avoided.

The log house structure consists of stacked logs overlapping, with slight flexibility in the seams. For this reason, log structures have a certain amount of “give”, so that they can adjust ever so slightly to strong fluctuations in wind, for example. When the storm passes, in most cases the house will settle back into place.

“It is because of this flexibility that timber is a popular building material in earthquake-prone areas around the world, such as Japan”, Löf says.

In addition to durability, the high heat capacity of Kontio log buildings helps to reduce energy consumption, which further lowers emissions. In warm weather logs retain heat energy, and release it when the temperature drops. That is why less energy is needed for heating and cooling: around five per cent less energy is needed for heating a log house, and as much as 50 per cent less for cooling.

Kontio’s goal is to contribute to controlling and lessening the effects of climate change and to reducing the carbon footprint. By choosing Kontio log products, you will be part of the fight for the good of the planet.

Attention, builders! Here’s how to reduce your carbon footprint

• In cooler areas, choose a plot where the building can be oriented so that the windows receive sun from the south side. Similarly, in hot areas, position the building so that strong sunlight will not heat the interior through the windows.
• Consider how big the building really needs to be. A smaller house takes less energy, material and money to build and maintain.
• Is the house adaptable to the future needs of a family? Even as you plan the building, keep possible future changes in mind.
• Use solid wood wherever you can: choose plank flooring, log walls and panels, and solid wooden furniture.
• Avoid plastics, and surface treatment products that contain plastics.
• Buy home electrical appliances that carry the class A rating, the highest energy-efficiency class. Wood-burning stoves and fireplaces can be connected to the house heating system.
• Make waste sorting as easy as possible: there should be enough space in the kitchen for practical containers for biowaste, glass, metal cans and cardboard.
• Ensure that roof structures are designed to properly accommodate solar panels. The more directly the sunlight can reach the photovoltaic cells of the solar panels, the more power they will generate.
• A sunshade is a good addition: it will keep the house from becoming uncomfortably warm in the summer, while still allowing the low-lying winter sunlight to provide what warmth it can.
• Situate the building on the plot of land so as to have the smallest possible environmental impact. For example, a yard with plentiful vegetation is good for the environment, as it supports biodiversity.