Sustainable Infrastructure

How do green roofs make cities more sustainable?

Green roofs can be defined as green spaces on top of a building. This green space can be below, at, or above ground level, but in all cases, they exist separately from the ground. Green roofs can provide a wide range of public and private benefits and have been successfully installed in countries around the world.

A green roof system is an extension of the existing roof that involves high-quality waterproofing, a root repellent system, a drainage system, a filter fabric, a lightweight growing medium, and plants.

In North America, the benefits of green roof technologies are not yet fully understood and the market continues to mature, despite the efforts of industry leaders. But in Europe, these technologies are well established, as a direct result of government legislation and financial support in countries such as Germany, France, Austria, and Switzerland, among others.

Green roofs not only provide building owners with a proven return on investment but also represent opportunities for significant social, economic and environmental benefits, particularly in cities.

In general, green roofs provide a variety of environmental, facility, corporate and social benefits. Some of them are mentioned here.

Economic Benefits

Although installing a green roof often involves higher upfront costs than a traditional roof, there are many economic benefits that can offset this, such as improving property values and marketability, especially in urban areas with small green spaces.

According to a University of Michigan study that analyzed a variety of benefits of green roofs, including rainwater management, improved health benefits due to reduced pollution, and energy savings.

However, the economic benefits of any single green roof will depend on its design, geographic location, environment, and the building itself.

Acoustic insulation

Sound is a major distraction, especially in a commercial building. Workers don’t want to hear the din of heavy traffic outside their office, let alone at home. A green roof is an additional layer of insulation and will absorb up to 30% of ambient noise pollution.

Aesthetics

There is no doubt about it: a green roof is visually appealing and, in the case of a public building, it attracts attention. The days of gray concrete and steel are behind us. People want aesthetically pleasing architecture and green roofs often play an important role in the overall design.

Rainwater management

Green roofs reduce stormwater runoff. The growing medium and moisture retention mats on the roof absorb rainwater, acting as a sponge and buffering the drainage system. This allows water to be released through evaporation and stabilizes groundwater levels.

Temperature control

The increased insulation offered by green roofs can reduce the amount of energy needed to moderate the temperature of a building, as roofs are the site of the greatest heat loss in winter and the highest temperatures in summer.

Air quality

Urban areas are typically noted for their lack of vegetation, which leads to a buildup of carbon dioxide and other harmful pollutants. A green roof makes the most of unused space. Plants absorb pollutants and emit oxygen, improving air quality and helping the environment.

Classification of buildings

If you’re hoping to build a sustainable home or upgrade your building’s rating with green certification, a green roof is an excellent place to start. Even better if you choose plants native to your local geographic area.

Biodiversity

City centers and urban environments are often inhospitable to birds, insects, and other creatures, and a green roof helps promote biodiversity by attracting wildlife. Additional features, such as bird drinkers and beehives, can be added to increase the green impact of the roof and reduce the carbon footprint.

Increases the marketability of the building

Green roofs increase the marketability of the building. Various research shows that businesses in buildings with green roofs found it easier to recruit and retain employees and tenants compared to businesses in a building with a traditional roof.

Local Job Creation

The growth of green roof markets provides new job opportunities related to manufacturing, plant growth, design, installation, and maintenance.

There is significant potential for new growth in dense urban areas that previously could not be used.

New Service Spaces

Green roofs help achieve smart growth principles and positively grow the urban environment by increasing amenities and green space and reducing community resistance to infill projects. Green roofs can serve any number of functions and uses.

Therefore, green roofs also contribute to the sustainability of a building. A green roof significantly reduces the need for air conditioning in summer and provides insulation in winter. Due to the reduced need for air conditioning in summer and less heating in winter, a green roof significantly reduces energy consumption.

So, given all the benefits, why aren’t all roofs green? Outside the United States, green roofs are much more prevalent. Despite their many benefits, a major obstacle is an initial expense; these typically cost two to three times as much as a non-green roof.

Net-Zero Architecture: Creating a modern life with zero carbon footprint

Net-Zero Carbon sets a clear direction for new and existing buildings towards a zero carbon built environment.

The construction industry currently accounts for more than 40% of the world’s carbon dioxide emissions, and 11% of that percentage is the result of the manufacture of materials used in the industry, such as steel, cement, and glass.

Despite the global pandemic, CO₂ emissions are increasing day by day, and it was in 2020 that an all-time high was reached, according to the Global Buildings and Construction Report. And in response, governments, and businesses have adopted action plans to limit carbon emissions and ensure a sustainable environment through net-zero carbon, for that it is important to talk about net-zero architecture.

What is Net-Zero Architecture?

When speaking of net-zero architecture, it should be understood that net-zero is the act of negating or canceling the number of greenhouse gases produced by human activity, by reducing existing emissions and implementing methods to absorb carbon dioxide from the atmosphere.

And a ZNC building is defined as a building with high energy efficiency that produces on-site, or acquires, enough carbon-free renewable energy to meet the annual energy consumption of the building’s operations.

In this type of building, carbon-based energy consumption is reduced first through building design strategies and efficiency measures, then through on-site renewable energy generation, and finally through the procurement of locally produced off-site renewable energy.

By establishing a net-zero balance of carbon-free energy consumption, this ZNC definition can be applied to all new and existing buildings, including those with limited on-site renewable energy capacity, such as buildings in dense urban environments.

Although net-zero buildings represent a fragment of new construction projects; the technology, tools, and knowledge that architects have acquired in recent years have made net-zero building design the new norm.

Therefore, Net-Zero Energy is when the building is able to offset or offset the amount of energy required to build and operate over its lifetime in all aspects of the site, source, cost, and emissions. In other words, the building can produce enough energy to cancel or “zero out” the amount of energy needed to operate on a daily basis.

Net-zero energy buildings are often designed with these three criteria: produce energy on-site through equipment such as solar panels or wind turbines, account for their energy use through off-site clean energy production, and reduce the amount of energy required through design optimization.

Therefore, net-zero carbon is achieved by reducing construction techniques and building materials that result in high carbon emissions. Simply put, Net Zero Carbon = Total Carbon Emitted – Total Carbon Avoided. Reducing embodied carbon through a concise selection of building materials and techniques often results in a decrease in the emission of harmful chemical gases, affecting occupants’ productivity and well-being.

Essential features of a Net-Zero building

Is it possible to create a Net Zero building from the design process and in the choice of solutions, materials, and products? Yes, it is possible, and here are some of the features that any Net Zero building should have.

Apply concepts of bioclimatic architecture

Designing projects connected to the climate and the local context can help save energy, which means using as much natural light as possible during the day while balancing thermal energy losses. The orientation of the frames, well-calculated solar protections, and absorbent and reflective materials in the right places, make the building able to passively take advantage of natural resources, according to the needs of each project.

Providing renewable energy in the building

Buildings can meet all their energy needs from non-polluting, locally available, and low-cost renewable sources, for example by harnessing the sun through photovoltaic panels or water heating panels. Or even using local wind systems or other renewable energy sources if possible.

Efficient lighting

When it comes to energy generation, it is impossible not to talk about the energy efficiency of appliances and lighting, and there must be a balance between generation and consumption, reducing losses and improving the efficiency of the equipment present in the building is vital. This means generating the same amount of energy with less natural resources or obtaining the same service with less energy with equipment that ensures efficient lighting.

Finally, the construction sector has currently implemented strategies to reduce CO2 concentrations, and one of these ways is the Net Zero architecture, which aims to reduce existing emissions and the implementation of methods to absorb carbon dioxide from the atmosphere through materials and construction techniques.

By Ingrid Luna

BIM and Sustainable Construction

Today, the word “sustainable” is used to mean so many things, but when excessive usage is removed and the core meaning of sustainability is observed, its value becomes apparent.

Sustainable construction aims to meet today’s needs for housing, work environments, and infrastructure without compromising the ability of future generations to meet their own needs in times to come. It incorporates elements of economic efficiency, environmental performance, and social responsibility, and contributes most when architectural quality is included.

Therefore, this term goes beyond installing energy-efficient mechanical systems; it is a philosophy that affects all aspects of the design and construction phases, as well as the ongoing maintenance and operation of the building into the future.

The initial phase of sustainable construction involves issues such as building design and management; materials performance; construction technology and processes; building energy and resource efficiency. The importance of sustainable construction in the long term is important, as a building must be designed and constructed with the foundations of energy efficiency throughout the life cycle of the building.

What is the role of BIM in sustainable construction?

Building information modeling (BIM) is now part of the design and construction industry, and it makes sense that it can play a key role in achieving sustainable building goals. But how do the two relate?

Here are three ways in which they relate:

Increased transparency during the design phase.
Increased efficiency during the design and construction phases.
Greater control during the operations phase.

Increased transparency during the design phase

The use of BIM on a project, from design, allows for a transparent process, confirming that design data is aggregated into a shared model, and every stakeholder on a project can quickly and easily access a complete summary in real-time.

This transparency allows contractors, engineers, suppliers, and more to bring their knowledge and expertise to the overall construction and operation of the building from the beginning making the project more sustainable in the design phase before the money is spent on materials or supplies.

This ensures that the most environmentally responsible materials and methods are used during construction, it also saves time and money by avoiding rework and schedule delays during construction through better upfront planning.

Increased efficiency during the design and construction phases

The use of BIM results in 3D virtual prototypes that can be easily shared and used for real-time collaboration and simulation to test both construction logic and sequence.

From estimating and takeoff to design and ongoing project management, each step of the design and construction workflow is reviewed and improved as BIM technology is integrated.

Each step in the process where BIM saves time, improves efficiency, enhances the design, and reduces errors provides a measurable opportunity to minimize the lifetime environmental impact of the building.

Greater control during the operations phase

Thanks to the high level of detail and ease of sharing 3D models created with BIM, a wealth of information and operational data can be transmitted to the building owner and manager, enhancing their ability to run the building to its fullest potential.

This benefit of BIM fits perfectly with the philosophy of sustainable building, which goes beyond design and construction and extends to the long-term maintenance and use of the entire structure.

There may be other ways in which BIM technology and methodology can help improve the sustainability of construction projects.