The need for sustainable construction

by Adriaan Woonink

Why do we need sustainable construction? Is sustainability a hype? Where is this pressure coming from? These are some of the questions many people have been wondering about. In this article we will highlight a few aspects about the rising need of sustainable construction.

Climate change

The need for sustainable construction comes from climate change. In the past few decades scientists and weather analysts started to see a rapid change on how the climate behaved, which affected the weather patterns. When they started analyzing what was happening they found out that the rise of the amount of greenhouse gasses affected how the sun is warming up the earth. Greenhouse gasses act like a blanket in the atmosphere. More greenhouse gasses mean less reflection of solar heat back into space, which means that more heat of the sun remains in the atmosphere.

Another aspect of climate change was the rise of the sea level. This affects a huge part of the global population, since most large cities are built right next to, or close to, the earth seas and oceans. Based on measured data from the past different computer models have been set up to make an estimation of what climate change could mean for planet earth. Based on these models the following conclusions have been made:

1. There will be an average increase of hot weather.

This means that, on average, global temperatures will rise. With the rising temperatures we will see more record hot weather as well, potentially damaging previously habitable parts of the world, reducing the area where people can live under normal conditions. This can be seen by analyzing the list of record hot weather by country (https://en.wikipedia.org/wiki/List_of_weather_records). A considerable part of the highest records were established in the last 20 years, whereas most cold weather records were established about 60 to 70 years ago.

2. There will be an increase in variance of weather patterns.

This means there will be more extremes  on both sides of the weather spectrum. An increase in variance means that, on average, there will be more record cold weather and record hot weather. Climate change does not automatically mean that the weather will be a lot hotter overall. When it is cold there is a higher chance it will get colder than ever before, potentially damaging crops and nature in general.

3. Overall, there will be less cold weather, much more hot weather and more extremes in both hot and cold weather.

The change in weather patterns will affect the world as we know it. The rising sea levels can force people to live more inland, creating less habitable land for more people. The extreme weather conditions can cause harvests to fail, creating famine. Eco systems will be changed or destroyed, changing the way we work with nature and the way nature works with us. In the end more people will be fighting over less resources.

So what can be done about climate change? In 2015 the Paris agreement was signed, stating that all participants would do what they can to reduce their output of greenhouse gasses. If all plans and ambitions will be met this means there will be an average increase in temperature of 2˚C. The increasing temperature will still affect the weather patterns and therefor the world, but not doing anything will further affect us.

Ever since scientists have started investigating what is happening with the world we have seen the same conclusions: The climate is changing and humans are most likely the cause of it. The science of climate change is not political, but the solutions are. If countries choose not to work on reducing the greenhouse gasses they produce, climate change can become disastrous. We can reduce the amount of greenhouse gasses by building our buildings in such a way that they require less resources to build, operate, maintain and demolish.

Trias energetica philosophy

The Trias energetica philosophy  has been set up by a professor at the Technical University of Delft in the Netherlands. The goal of this philosophy is to keep in mind the right order in which sustainable measures should be applied in the field of construction. If the steps are not taken in the right order a good opportunity is missed to reduce the energy consumption of the building and thereby the production of greenhouse gasses.

Step 1: Reduce the need for energy

To reduce the need for energy extra care has to be taken into account for the design of the building. Reducing the need for energy means to apply more insulation in all parts of the building, to reduce the heat loss. Making the building more airtight is also an important aspect. The size and orientation of the windows becomes more critical as more insulation is applied. If this is not designed carefully the building will overheat during the summer, which forces people out of the building, or forces them to buy an air conditioner. This will then consume more energy, which was the exact opposite goal of applying more insulation in the first place. In countries like the Netherlands using an air conditioner was traditionally never necessary, because the number of hot days in the building was so low it did not require active cooling. However, because buildings are insulated much better the heat remained in the building for a longer period, causing people to buy air conditioning. Reducing the heat loss in the winter should not mean to increase the energy consumption in the summer by using an air conditioner. A well balanced design is the best approach to reduce the need for energy in the first place.

Step 2: Use renewables as much as possible

Renewable energy in buildings usually takes the form of solar panels, but wind power, solar hot water and heat recovery in air ventilation and waste water are becoming more common applications as well. The heat recovery in air and waste water is sometimes also called step 1b, because it involves reducing the need for energy, with energy already available within the building. Solar hot water will reduce the need for active heating of the hot water used in the building. Wind power is not always easy to accomplish, and many small wind mills are not financially feasible because of the small scale. The solar panels generate electricity directly from the power of the sun and are usually applied to on the roofs of buildings.

Step 3: Use fossil fuels as efficiently as possible

The energy that is needed to use the building that cannot be reduced or generated by renewable energy sources should be used as efficiently as possible. This means that the latest energy efficient technology should be used.

Following these steps in this order can greatly reduce the energy consumption of buildings, thereby preventing the production of greenhouse gasses. In turn this will reduce the growth, or increase the reduction of greenhouse gasses. This will guarantee that future generations can use the earth as their own habitat.

Adriaan Woonink

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