Log Homes and the Environment
Jorntrahus houses are built to Swedish Building regulations, which have an average 10% better insulation standard than the UK building regulations.
To judge how warm a house built with particular construction type is going to be we compare the 'U values' of the materials it is made out of.
The U-value is defined as the rate at which thermal energy is conducted through unit area, per kelvin temperature difference between its two sides.
U = rates of loss of energy surface area x temperature differenceThe lower the U value the better is the insulation.
Current U values in Jorntrahus houses and the UK requirements
Jorntrahus Approved document L1 %improvement Walls 0.267 0.35 23.7% Windows 1.56 1.8 13% Roof 0.24 0.25 4% Ceiling 0.16 0.16 0% Floor 0.215 0.25 14%
Because a Scandinavian Log Cabin House is so well insulated :-
All the wood in a Jorntra house is sourced from pine forests in the Norrbotten region in the far North of Sweden. These forests are the main source of income for the people of the region. They manage the forests, harvest the trees and replant them using documented techniques that have been used for over 50 years. The wood supplied to the Jorntra factory is certified to prove their wood is from a sustainable source. The local Forestry Board has a sustainability policy statement which is available for you to view along with information about the Swedish Forestry Act.
The Carbon Cycle
As is well known our environment is being damaged by human activity. One of the major factors damaging the planet is the release of Carbon Dioxide into the atmosphere. Carbon Dioxide is a "Greenhouse gas" which helps to form a sort of blanket around the Earth preventing solar heat from being radiated out into space. By studying sediment cores from the sea beds and ice cores from the vast ice sheets of Greenland and the Antarctic scientists have been able to demonstrate that at periods in the Earth's history when Carbon Dioxide levels have been elevated then there has been a corresponding increase in global temperature. Thanks to mankind burning fossil fuels present day Carbon Dioxide levels are high, around 30% higher than they were 200 years ago, and global warming is an imminent danger.
Trees are our friends in combatting global warming. They absorb Carbon Dioxide from the atmosphere by the action of Photosynthesis and store the Carbon in their wood. The more trees we grow the lower atmospheric Carbon Dioxide will become. By chopping down trees, making log cabins out of them, and growing new trees, we are keeping Carbon Dioxide out of the carbon cycle.
However at some point in time a log cabin is going to wear out and will be dismantled. If the logs are burned the Carbon stored is released back into the atmosphere as Carbon Dioxide. We can delay the event by recycling the logs as chipboard, but at some point the wood will burn or rot and the carbon cycle will continue. So growing trees is not a solution to global warming, but it is at least neutral. Global warming is not made worse by growing trees, and very little energy is used in growing and harvesting the crop. The same could not be said of other forms of house building.
Conventional houses are built on concrete foundations with brick walls joined together by cement. The cement industry is one of the biggest users of energy in the world, and any reduction in its consumption will have a direct effect on carbon dioxide emission. By eliminating brickwork you are already taking a major step in the conservation of energy, not to mention mining damage from chalk pits & clay pits.
The weight of a log home is also substantially lower and foundations do not need to be as substantial leading to savings in concrete. It is even possible to eliminate concrete foundations entirely by using screw pile foundations.
Also the interior walls are made of timber requiring no gypsum, another energy intensive product that leaves its scars on the earth's surface.
The same with roofing material where mineral felt made using waste shale is used instead of clay tiles that need to be dug up, shaped and baked in an oven.
Ultimately we believe it is possible to make a house with no 'wet trades' at all.
Some other areas we are keen to promote are: