How often have you wanted to design green instead of conventional architecture but have yet to know where to start? You know that green buildings require energy efficiency, but how can you calculate that efficiency? You know green roofs are suitable, but should you apply this solution always and everywhere? Using solar or photovoltaic panels on your building is great, but is it always the best and most cost-effective source of electrical energy and heat?
An architect can partly address numerous design-related issues, but more is needed to guarantee that you will create a green building. Instead, you may introduce some elements with more or less success.
The green building design approach
Green building design requires an integrated and systematic approach, which implies a clear understanding of what we do, why we do it, what we want to achieve, how to achieve it, what tools and software we can use for calculations, etc. Unfortunately for us architects, a green building requires lots of calculations. Still, once you learn how to do them, you will realize you have a higher knowledge and understanding of architecture. Not only will your buildings be better, but you will be at a higher professional level.
As architects who face the same dilemma as you, we want to offer clear explanations of each step in the process so that you can fully understand all the stages and continue your incredible journey into the world of green building design.
We tried to group all the steps logically, following the actual phases and processes in designing. Furthermore, we gave the complete picture using as few descriptions as possible, explaining simply the final purpose of each step and what it means within the context of design, the building itself, and your creative process.
Each green building has its own set of specific parameters and characteristics. You don’t have to apply all the principles of green buildings in one structure, nor is it necessary. Still, it is crucial to find the right strategy that contains the principles optimal for your building, following the environment where the building will be situated.
Before we delve into the step-by-step guide, it’s crucial to understand the primary objectives of green building design. These goals will guide your decision-making when selecting solutions or systems or facing uncertainty.
Green building goals
Green building design is a complex process requiring us to improve every step and construction element. The general goals we want to achieve with green building fall into the following areas:
- Life cycle assessment approach– considering the building within its life cycle period, from material production to demolition or recycling;
- Siting and structure design efficiency – the correct siting and orientation on a plot, optimization of its size and shape, building envelope, and building structure;
- Energy efficiency – Optimization of energy consumption;
- Water efficiency – Reduce and reuse water in the building;
- Materials efficiency – Using materials whose production, installation, use, and dismantling have the lowest impact on the environment;
- Waste reduction – Optimizing the amount of waste generated during all the stages of the construction process, from material production throughout the life cycle of the building;
- Indoor environmental quality enhancement – Providing a non-toxic and clean indoor environment, optimal lighting level, thermal conditions, ergonomics, etc.
Once you adopt the basic principles of green building, you can make all future decisions with understanding. To introduce you to the process of green building design gradually, we’ll explain in 12 steps the topics, areas, and goals that need to be defined, calculated, understood, and analyzed.
Unlike conventional architecture, green architecture requires the architect to thoroughly and closely examine all possible data about the construction site. Naturally, the site’s climatic characteristics are among the most critical factors influencing our strategy. They will also affect most decisions in designing green buildings, and we’ll often refer to climatic characteristics.
Steps to Design Green Architecture
Step 1. Site Assessment
The first step on our green building design journey is site assessment. To exploit the site’s potential, you should follow the following steps:
- Topography Analysis: This includes contour mapping, identifying unique topographic features, and analyzing the slope stability risks if necessary.
- Climate Data: Some of the most critical inputs include data on solar radiation, solar time, season characteristics, horizontal and vertical sun path diagrams, humidity level, and wind direction and strength.
- Analysis of Hydrology: This means identifying flood hazard areas and delineating wetlands, lakes, streams, shorelines, and rainwater collection and reuse opportunities.
- Vegetation Analysis: This includes identifying primary vegetation types, greenfield areas, significant tree mapping, threatened or endangered species, unique habitats, and invasive plant species that we need to control.
- Soil Analysis: This includes identifying prime farmland and healthy soils to protect them from construction and save them for agriculture.
- Analysis of Human Use: This includes identifying previous uses of the site, if any, or some other characteristics that are important for the overall quality of the site, such as the views that we want to preserve, adjacent transportation infrastructure, adjacent properties, and construction materials with existing recycle or reuse potential.
Suppose the site already contains a building or suitable construction material you don’t want to keep. In that case, you can consider rehabilitating existing structures using reclaimed or recycled materials and components.
Step 2. Maintaining and Gaining Heat
After site analyses, the following necessary research is the optimization of the building envelope.
Architects reduce the building envelope mainly to its aesthetic characteristics, assuming it reflects its functions. However, in sustainable design, the building envelope has a far more significant role, and practice should give it much more attention through optimization. The building envelope comprises all the elements that separate the indoor and outdoor space.
The building envelope releases heat out (heat losses) and lets it in through transparent components such as glass surfaces (heat gains).
The tasks the building envelope performs in the green building include:
- Maintaining and gaining heat
- Avoiding overheating
- Decentralized ventilation
- Using the daylight
- Generating electricity
The building envelope protects us from external colds, prevents us from losing too much heat generated indoors in winter, and protects us from excessive outer heat in summer.
Its primary role is to ensure and maintain optimal thermal comfort, whether it’s hot or cold outside. By optimizing a building’s envelope segment, heat flow through it can be controlled.
Let’s examine which optimizations or processes we can apply to maintain and gain heat through the building envelope.
Surface optimization and envelope geometry are practically one of the first steps in green building design, following the analyses of the site and climatic characteristics. They form part of the preliminary design phase.
The first creative sketches accompanying the interior layout considerations, starting with the building shape design, are essential to immediately maximizing energy efficiency.
The variable for assessing compactness is the heat-transferring enclosing surface A ratio to the heated volume V – A/V ratio.
Thermal zoning is the next step to consider from the very beginning of the design process. It implies that the architect should design the interior layout according to different temperature requirements. For example, spaces that are not in constant use or do not need heating, such as utility or storage rooms, should be oriented towards the point that usually does not receive sufficient solar energy, such as the north. The recommendation is that rooms with high thermal requirements are orientated towards the south to obtain additional sun heat on that side.
The most common association with green buildings is good insulation of exterior walls or Thermal insulation of opaque components, which is one of the most important steps towards making the building we design green. The most important parameter for defining the wall layers, insulation type, and thickness is the U-value (or R-value equivalent to this parameter, U=1/R).
Opaque elements of the building whose U-value we calculate and which should be well thermally insulated are external walls, roofs, components in contact with the soil, and rooms with a temperature difference.
Transparent components are essential in preventing heat losses through the building envelope; their influence increases depending on the surface they occupy. The most critical parameter of the thermal characteristics of transparent surfaces is the quality of the glass, which, like in opaque elements, is expressed by the U-value parameter.
The most crucial concept of passive solar radiation is to orientate the building so that the largest surface of its façade faces south and large glass surfaces receive as much solar radiation as possible. Also, we should build roof overhangs to protect the transparent surface from overheating in summer because the sun is higher in the sky in summer than in winter. The most important rooms where we spend the most time should be arranged on the south side, while less critical utility rooms or bedrooms should be on the north side, with much smaller openings to prevent too much heat from being lost through them.
Passive solar systems are architectural concepts where the entire building acts as a collector that captures and stores most of the solar energy. In contrast, active systems rely on installing additional equipment in the building.
Active solar thermal energy gains mean that we can use the building envelope to actively collect thermal energy by installing active systems such as photovoltaic or thermal panels on the building façades or roofs.
As shown in step 2, heat collection and prevention of heat loss are among the building envelope’s most essential roles. At the same time, the building envelope should protect the indoor space from overheating in summer. Overheating primarily occurs through transparent surfaces because the glass can let short-wave solar radiation (ultraviolet radiation) in, heating thus materials, objects, and air inside. Still, it cannot pass the reflected long-wave heat radiation. This property of glass is called the greenhouse effect.
Step 3. Avoiding overheating
To avoid overheating, we should consider location, the form of construction, the type and intensity of ventilation, glazing, and sun shading when designing green buildings.
Step 4. Decentralized natural ventilation
In addition to temperature regulation, it is essential to regulate the air quality in the building by decentralized ventilation. Good air quality depends on the purpose of the building, the size of rooms, and the number of people using the building.
Energy optimization of the building is vital, and it requires high airtightness of the building envelope components. However, we must also ensure a sufficient amount of fresh air inside the building. When designing green buildings, we need to consider two types of ventilation: natural and mechanical ventilation.
Step 5. Using the daylight
Daylight is one of the most important factors affecting the comfort and quality of interior space. The building must be provided with as much natural light as possible, which can be enabled by its shape, form, and orientation.
The third chapter of designing a green building involves optimizing building services. This approach cannot be replaced by the sole use of active, expensive, and modern technical systems. The precondition for good-quality green building design is to execute all the previous steps well and complete the whole process using optimal technological systems.
Optimization of building services
The processes that we need to optimize in a green building are:
- Gaining and distributing heat.
- Gaining cooling energy and dissipating heat.
- Optimizing mechanical ventilation.
- Optimizing the artificial lighting.
- Generating electricity and using it efficiently
- Reduction and reuse of water.
The level of optimization and the type of systems and technology that we plan to use will depend on the size of the building, its purpose, the conditions of the site where the building is located, and finally, on the investor’s budget.
Before turning to technology to solve a problem, we should explore and utilize all possible non-technical or passive solutions. In other words, we should prioritize methods that don’t rely on technology, such as changes in behavior, policies, or natural processes, before considering technological interventions. The idea is to use technology only when we’ve exhausted other, simpler, or more sustainable options.
Like everything else, money, i.e., expensive technology, is meaningless if the building has not smartly utilized all the possibilities offered by free solutions, primarily solar energy for heating and lighting.
When exploring technological solutions for the mentioned services in buildings, it is essential to pay attention to the environmental aspect of the energy sources used by the technology. It is desirable that these are renewable energy sources and that CO2 emissions are minimal.
Step 6. Gaining and distributing heat
Providing heating is one of the most essential functions in buildings. Naturally, heating needs can dramatically vary depending on the site’s climatic conditions where we build the house. The second most important factor affecting the amount of fuel needed for heating is the optimization of the building envelope to minimize heat losses through it. If the building envelope is not maximally insulated, it’s never worth investing in a more expensive or better heating system.
Step 7. Gaining cooling energy and dissipating heat
In addition to heating, cooling is the next topic for achieving thermal comfort in a building. As with heating, the precondition is that the building envelope is optimally designed, constructed, and well thermally insulated. In colder climates, it is often unnecessary to have a particular cooling system; instead, good optimization in the planning process can ensure good thermal comfort in the summer. However, in the more significant part of the world, especially under the influence of climate changes leading to an increase in the outdoor temperature, buildings need additional cooling in the summer.
Step 8. Optimizing mechanical ventilation
Building ventilation constantly replaces polluted indoor air with fresh outdoor air to maintain hygienic conditions for people’s healthy and comfortable stay. In addition, ventilation heats the air if necessary, removes excess moisture and harmful gases from the atmosphere, and cools the air in summer. We can broadly classify building ventilation as “natural” or “mechanical.”
Step 9. Optimizing the artificial lighting
Lighting is another significant system in buildings regarding energy consumption and an essential element influencing a space’s ambiance, comfort, and quality.
Step 10. Generating electricity and using it efficiently
Generating electricity and using it efficiently means installing solar or photovoltaic (PV) cells. Solar cells are electronic devices that convert sunlight’s solar energy into electric energy. Solar cells convert energy as long as there is sunlight. You can read more about this topic here.
Step 11. Reduction and reuse of water
The use of water in green buildings is also an important topic. When it comes to consumption, several strategies can optimize water consumption in buildings. These are Reducing water consumption by using water-efficient devices, Domestic Rainwater Harvesting, Using treated greywater, using Blue-Green technologies, and Using biofilters in households.
Step 12. Construction and Materials
Proper use, type, and quantity of material are crucial aspects of green building. The basic principles that architects should follow include:
- Reducing requirements – optimizing the use of materials, reducing their quantity per unit of function;
- Increasing efficiency – choosing materials with the same characteristics but lower environmental impact;
- Use local resources – build by using or reusing local materials;
- Recycle/renew materials – use recycled (industrial) and restored (natural) materials;
- Compensate for or neutralize environmental impacts – choose products that compensate for their environmental impact (CO2-neutral).
As you can see, designing green buildings is possible. With a complete understanding of all the steps, the use of different tools and software, continuous learning, improvement, and significant commitment, you are on the way to truly becoming a green building architect.
The fact you are reading this text now means you are determined to learn and improve your knowledge. We want to help you along the way by adjusting your understanding of green buildings so that together, we can become a community of architects dedicated to preserving our planet.
We will continue to simplify the knowledge of green building and share it with you.
