With the increasing need to reduce human impact on the planet, the building industry has been seeking more sustainable solutions to minimise the consumption of natural resources, reduce greenhouse gas emissions and promote sustainable development.

Buildings are responsible for a significant portion of energy consumption and carbon emissions. Therefore, making buildings more sustainable is the key to reducing environmental impacts and transitioning to a low-carbon or carbon-neutral economy, as expected by 2050.

In this article, we discuss some issues concerning sustainable and greener buildings, as well as how we can make a difference when constructing a property.

Photo by Darya Jum – Unsplash

What is a green building?

A green building is a building model that pays special attention to sustainability and environmental protection and saves natural resources both during construction and later use. This category of green building uses techniques, technologies and materials to achieve better energy efficiency.

What does green building entail?

Foremost, green building practises and strategies aim to reduce environmental impact, promote energy efficiency, conscious water use and the use of sustainable materials from the beginning of the building process.

The land on which the property will be built is one of the first factors to consider. It is important to conduct a thorough analysis and consider factors such as access to public transport, proximity to green spaces and the presence of basic amenities. Such an initial, thorough assessment will help reduce the environmental impact and improve the quality of life for residents.

Another maxim to keep in mind when building in an environmentally friendly way is energy efficiency. Developing a sustainable project requires time and detailed studies on how to maximise the use of renewable energy such as solar or wind power. To maximise the use of clean energy, space organisation, solar orientation, and building thermal insulation must all be considered. This last aspect is one of the biggest problems in the construction of buildings in Portugal. Thermal insulation was not properly planned or simply ignored in Portuguese buildings. As evidenced by this legislative decree, newer constructions now take thermal insulation parameters into account. Controlling the energy efficiency of a building reduces the consumption of non-renewable energy (such as electricity) during extreme temperatures in summer or winter.

The conscious use of water is another essential feature of green buildings. Alternatives for rainwater collection and reuse, for example, can be considered in this regard. The low-flow taps, energy-saving showers and dual-flush toilets are the most common tools used in homes to manage water efficiency. Even in homes that were not designed to be environmentally friendly from the start, these common tools can make a difference. In villas with gardens, the landscape design must include autochthonous plants for efficient maintenance with low water consumption.

The selection of sustainable materials, i.e., materials with a low environmental impact, is one of the pillars to be considered when constructing green buildings. Materials should be certified, recyclable and from renewable sources. Opting for local materials not only supports the local economy, but also helps reduce carbon emissions from their transport.

What sustainable materials are there for green buildings?

• Wood

The use of wood in sustainable building may seem like a contradiction in terms, but there are already controlled sources from which the wood comes. This means that timber from managed forests is tracked and quality is guaranteed from beginning to end. When a tree is cut down in these forests, it is replaced by a younger tree. Only in this way can the forests be constantly renewed. The wood can be used for the building structure, cladding, flooring and other elements that ensure the construction of the property.

• Sustainable building materials

The conventional construction sector is one of the most polluting sectors of all. Globally, construction consumes 75% of natural resources, including 40% mineral resources, 40% energy and 16% water. Fortunately, construction practices have changed, and more environmentally friendly materials are now being used. Some of these materials are manufactured and marketed in Portugal, resulting in a lower carbon footprint during transportation.

An example of such materials is the hemp blocks produced by Cânhamor from Ourique in Beja. Hemp is a plant that thrives in different soils and has fast growth, so it is ready for harvesting in 3 to 4 months. Processing of the plant is completed in just two weeks, and the hemp blocks are ready to use, offering durability and strength. These blocks also have insulating and self-regulating thermal properties, resulting in lower energy consumption when heating and cooling the house.

Pombal manufactures yet another building material that has been highlighted on the Portal de Construção Sustentável (Sustainable Construction Portal), an online site that showcases projects, products, and businesses that want to make a difference in the construction industry. Preceram produces a thermal and sound insulation tile with an unusual shape that provides comfort and energy savings.

Cork is one of the best-known materials in the world, and much of this sustainable material comes from Portugal. Cork is harvested from the cork oak, a tree native to Portugal and other Mediterranean countries. It is harvested without harming the tree, which regenerates and produces more cork throughout its useful life. Cork has excellent thermal and sound insulation properties and is fire-resistant. There are various uses, from flooring to panelling to furniture. In Portugal, several companies produce processed cork, such as Amorim.

• Recycled building materials

Recycled materials are an important part of green building. They reduce the consumption of natural resources and minimise environmental impact. For this reason, we should adopt a circular economy and choose materials that can have a second life. On the market, recycled building materials provide the same guarantees as conventional materials.

Recycled concrete is made from demolition debris or masonry waste. This recycled material can be used for many applications, including floors, slabs, and other structural elements in a green building.

Recycled plastic comes from PET plastic bottles, plastic packaging and other plastic waste and can be made into tiles, flooring, cladding and pipes. As plastic is one of the most commonly discarded materials today, its reuse in construction is an excellent alternative.

Is it significant that the property be energy efficient?

Yes! The energy efficiency of a property is important for both the environment and the occupants' monthly expenses. Energy efficiency is the intelligent and rational use of energy, the observance of which brings several benefits.

Monthly costs decrease because less energy is consumed. Installing proper insulation, efficient windows, efficient heating and cooling systems and energy-efficient lighting can significantly reduce energy costs in the long run.

Buildings are responsible for a significant portion of the world's energy consumption and greenhouse gas emissions. By making a property more energy efficient, you reduce the amount of energy needed to live. This reduces dependence on fossil fuels and contributes to mitigating climate change by reducing greenhouse gas emissions.

Properties with higher energy values achieve a higher value on the property market. Buyers are becoming more aware of energy efficiency and looking for properties with lower environmental impact and monthly costs. Therefore, improving the energy efficiency of a property can increase its value and attractiveness in the real estate market.

The energy performance certificate of a property is required in Portugal when it is offered for sale or rent. Failure to present this document can result in a hefty fine. The document is issued by ADENE-certified technicians, who rate the property on a scale from A+ (very efficient) to F (not very efficient). The certificate is valid for ten years. If you want to learn more about the energy certificate, read this article.

A property's energy efficiency benefits both the economy and the environment. It helps to reduce energy costs, contributes to environmental sustainability, provides comfort to occupants, and raises a property's market value. As a result, it is strongly advised to construct properties following energy efficiency principles.

In Portugal, green buildings are a growing trend and are in line with the country's efforts to promote environmental sustainability and energy efficiency. In Portugal, there are several incentives and regulations for green buildings. This should be the beginning of the building transition in the country.