The goal: carbon neutral buildings by 2050

In the context of climate change, the issue of environmental awareness is increasingly raised, not only in everyday life but also in the context of the built environment. We explored ways to minimize the carbon footprint of a building with architect Mónika Tornóczky, Product Manager at Alukönigstahl, as the Central European Representative for Schüco and Jansen.

Nowadays, environmental awareness is increasingly important in the field of architecture. What solutions, options and decisions lead to a building being eco-conscious?

There are many tools in the hands of architects that may reduce the environmental impact of a building. These include the inclusion of a building into the landscape, its orientation, mass formation, and establishment of various openings.  These are simple architectural tools that already influence the environmental impact of a property during its construction and during its life-cycle. At present, the environmental performance of a building is primarily determined by its lifetime carbon emission, so the main focus is on reducing greenhouse gas emissions. The carbon footprint of the built environment counts for around 39 percent of the global carbon footprint.

The carbon footprint of a building is also affected by data relating to the production of building materials and the construction of the building. Thus, in addition to the so-called low-tech devices I mentioned before, it is also important to know what the house is built from, what innovative solutions and high-tech tools are used in the fields of both building materials and building management solutions. By integrating these, we can also influence the carbon footprint of a building.

Could you give us some concrete examples of the solutions that serve this purpose?

There are already many building materials on the market that are made of recyclable materials and can be produced with lower energy consumption, so the carbon footprint of the installed building material is smaller, but these calculations also need to take into account where the material is produced and installed, to eliminate the high environmental burden of transport. I would like to highlight innovative solutions for doors and windows. The main consideration here is not only the good thermal insulation of the doors and windows, but also that the amount of natural light allowed into the interior, for example, has a great influence on how to use them well. Another important factor for glazing is its overall energy transfer capacity, which is denoted as g value. The so-called passive solar heat gain can be achieved by glazing having a g-value that is not too low. It is worth highlighting here the fact that the better the heat-insulated glazing is, the smaller the amount of energy that it can let through the glass, thus losing the solar gain, which is practically a passive means of protecting the environment. As such, when choosing glazing, it is also worth paying attention to the good ratio of heat insulation and total energy transmission ability. Excessive heat stress during the summer period can be reduced effectively by the use of exterior shades, which is why it is essential to use them for large, south-facing glass surfaces. Internal blinds can be used to control the amount of light and protect against being seen from outside.

And what else can we do?

For windows and doors, the use of window-mounted ventilation equipment is also a good choice. Ventilators with heat recovery can increase the temperature of the incoming fresh air with the heat of the exhaust air, thus maintaining favourable indoor air conditions with low energy consumption. This has to do with how healthy a building will be.

Where can I find truly professional information on the subject? 

The Hungary Green Building Council (HuGBC) is a Hungarian affiliate of the World Green Building Council. They are active in many countries to explore the potential for reducing the carbon footprint of the building stock. WorldGBC has just been completed a report on how buildings and infrastructure could achieve 40% lower carbon emissions worldwide by 2030; and how buildings can deliver 100% net zero carbon emissions by 2050. At home, it is HuGBC that has embraced all the sustainable architectural efforts in Hungary that may be of interest to the local market.  This includes passive houses, active houses and autonomous houses, which use various architectural tools and even the latest of such technologies. They regularly publish articles on the topic and focus all the knowledge packs on the topic. They deal more deeply with environmentally conscious building certification systems, which also assess the buildings implemented according to different complex criteria. At present, almost all newly developed office buildings in Hungary have been certified in one of the international environmentally conscious certification systems. In this sector, therefore, efforts have been made without top-level regulation. The certified buildings database is available on the association’s website.

If you want to build an eco-friendly house in the family home sector, what are the aspects to consider?

It is worth incorporating a holistic approach to single-family homes and choosing environmentally conscious solutions for building materials, energy consumption and comfort.  This, as I have already mentioned, starts with the orientation and mass formation of the building, which already supports favourable energy consumption. It is important that openings on the building – windows, doors, curtains, etc. – should be able to cope with extremely high energy requirements during the winter and summer, taking the sun into account. In the summer, we need to protect the building from overheating, so it is advisable to use exterior shades to control how much light and heat you want inside the building. In the winter, however, if we do not use the sun shade, we may achieve solar gain. When choosing individual systems, it is also worth considering the material of our windows, in addition to the insulation and total energy transmission. Here you should choose products that are recyclable or recycled. Today, there are several certifications that take this into account. Such is the Cradle to Cradle rating that appears on Schüco doors/windows and curtain wall systems. This certification shows how environmentally-friendly a given construction product is over its lifetime. For example, products made of steel and aluminium are highly recyclable. Building material manufacturers increasingly work with an eco-conscious approach. Product development takes into account, for example, recycled material content and how a product may contribute to the creation and operation of environmentally conscious buildings through its various product characteristics or capabilities. From the perspective of the future, it is certainly positive that both the client and the manufacturing side consider it increasingly important to make environmentally conscious decisions.