Sustainability and zero-carbon

According to UNESCO, sustainability is a long-term goal. Sustainable development is the many processes and pathways to achieve it.

Planes, power stations, cars and factories are easy to point to as the roots of greenhouse gases. However, buildings and infrastructure are the most significant contributors to carbon emissions.

Buildings and construction sites are accountable for 40% of global carbon emissions. Operational emissions (like heating heat, cooling) accounted for 28%. The remaining 12% comes from combined carbon emissions or preparatory carbon emissions associated with materials and construction processes used throughout the life cycle of the building.

Today less than 1% of new buildings are constructed to be zero-carbon or zero-carbon ready. Zero-carbon buildings and communities might seem complicated and rare just yet, but they are quickly becoming mainstream with the support of global organisations worldwide. 

The construction industry is one of the most significant users of global resources and contributors to pollution. It, thus, has a considerable responsibility to aid sustainability.

Sustainable construction uses renewable and recyclable resources and materials. During construction projects, waste and energy consumption needs to be reduced to protect the natural environment around the site.

“Nature is the best architect, and nature developed the best designs.”

Chris Precht, architect

There is a perception that sustainable construction is expensive, making it less attractive. Meanwhile, cost remains a concern for many; owners of green buildings report that money is saved through reduced operating costs thanks to sustainable materials.

Some companies involved in design and implementation have already committed to ambitious strategies. 

Skanska (Sweden) is taking severe steps to enable the full life-cycle impact of projects to be assessed. Dalmia Bharat Cement (India) is working to become carbon-negative by 2040. The University of California (USA) committed to a goal of 100% renewable energy by 2025. The new Bee’ah HQ in Sharjah (UAE) aims to become the most sustainable building in the Middle East. It will be 100% powered by on-site solar PV.

Norway has committed to organic-free construction. As part of its response to climate change, Vancouver (Canada) has pledged to reduce consolidated carbon in new buildings by 40% by 2030. 

The European Union also introduced a zero-net energy target for new buildings and significant refurbishments from 2020. But Malta somehow did not get the memo.

As of 2021, all new buildings must be nearly zero-energy buildings (NZEB). When a building is sold or rented, energy performance certificates must be issued, and inspection schemes for heating and air conditioning systems must be established. But as far as I understand, Malta somehow did not get the memo. 

What makes a property zero-carbon? 

In Europe, there are mandatory energy performance standards for new buildings. However, these standards vary significantly between members of the EU.

Joanna Williams, the author of the Zero-Carbon Homes: Road map, describes zero-carbon homes as “a home, from which there are zero-net CO2 emissions during operation”.

For one year, the net amount of energy generated on-site should equal the net amount of energy required by the building.

Living in a house that doesn’t meet your needs might have been okay when you spent more time at school or your workplace and just went home for the night. However, many people like me have been stuck indoors during the Covid-19 pandemic, and the lack of space or poor soundproofing, inadequate ventilation or no outdoor access are all shortcomings that made my months inside kind of intolerable. 

How can you achieve zero-carbon building?

Designing a zero-carbon home requires tailored solutions to different locations to maximise site advantages like solar or cool wind passage and daily temperature variations or to identify alternative solutions when these are unavailable.

It’s possible to build efficient new homes, although there are fundamental principles to keep in mind. You should choose a site that allows renewable energy generation, passive solar heating and cooling, and food production. You must incorporate energy efficiency strategies with renewable energy options from the project’s outset. Also, maximising passive design strategies to reduce energy demand is a must. Choosing appropriate materials that enhance the passive design strategy and have a low embodied energy, like using high insulation levels or high-quality windows. 

With existing buildings, you can update the insulation or, in Malta’s case, introduce insulation to reduce air leaks. Also, you need to add alternative energy systems like solar thermal panels for hot water and/or photovoltaic panels to make electricity. 

Are there any benefits?

These homes should be low maintenance and future-proof, not only for you but also for the environment. It will be a healthier building to occupy with no condensation, drafts, mould, cold spots or freezing rooms, and fresh air from natural or mechanical ventilation.

Improved health and comfort by better managing the fresh air and temperature in the building. Reduced noise because of better insulation and airtightness. Do I have to mention the lower energy bills? A zero-carbon house means you would have no energy bills; a negative-carbon home would even make you money. That is kind of amazing, right?

Although the real question is. Can we afford a zero-carbon home?

Let’s be frank, building a house is not cheap. You have to calculate the increasing construction costs, land prices, and many other expenses that characterise the construction of a family home.

A zero-carbon house’s construction costs far exceed a traditional home’s cost. 

On the other hand, we have to ask ourselves what we can expect in return by incurring additional costs? 

The operating costs will be significantly reduced when building a zero-carbon house, which results in a return on the extra expenses invested in the long run. The problem is that these additional expenses must be spent during the construction of the house. That’s when the question becomes important, how much is the extra cost?

Based on the experience so far, it is not an impossible task because, with the application of unique technology, a significant amount of mechanical units will be replaced by heat exchanger ventilation equipment and modern equipment utilising alternative energies. 

Cut to the chase; we can expect an additional cost of about 20%. Deciding whether we can finance this expenditure is a matter for everyone individually. Still, it is certainly stimulating, especially with the ever-increasing energy prices.