30 Oct 2023
Pursuing energy efficiency in architecture leads to lower environmental impact buildings that cost less to operate. While optimal passive design comes first, active systems and renewable energy also play an important role.
The aim of sustainable architecture is to create green building designs. One essential aspect of sustainable building is focusing on saving energy so as to minimize usage as well as costs. For the African architecture firms wanting to add sustainability into their operations, they should mainly concentrate on energy efficiency.
The following article presents a discussion of the most suitable energy-saving strategies for architects and building owners to improve their building’s energy performance.
Why Energy Efficiency Matters
There are several compelling reasons why improving energy efficiency should be a priority:
Savings – reduced energy usage means lower utilities and therefore, money in the pockets of the owner and tenants. This is because energy-efficient buildings incur low operational and maintenance costs.Â
For instance, the inclusion of passive solar design strategies such as good alignment and shielding can significantly reduce lighting and cooling expenditure per annum in a given structure.
Sustainability – Burning less fossil fuels to power the buildings minimizes greenhouse gasses for a low carbon footprint. A large amount of energy use and emissions within a city come from commercial buildings. Climate change is largely attributable to greenhouse gases. Architects have an option of designing energy-efficient buildings which goes a long way in cutting down on environmental impacts for their projects.
Green and energy-efficient buildings have a competitive advantage. Architect, as a salesperson, has many benefits that help him or her to sell to other persons, one of these advantages is a sustainable design, which helps architects attract other people’s interest easily. Expertise in high-performance design could be an advantage for projects implemented in emerging markets, especially in Africa.
Energy performance is required according to energy codes and green building certification standards like LEED. Energy-efficient building design is a matter of regulation law. Some projects might need to achieve energy performance criteria in order to get approved.
Indoor air quality, light, and temperatures are building qualities that make energy-efficient buildings more comfortable and healthy places for occupants.
Optimizing on-site energy – This helps to minimize strain on the utility grid for grid reliability. In most developing countries, this enhances grid reliability.
Passive Building Design Strategies
A passive approach to energy efficiency entails ensuring that a properly designed building requires as little energy input as possible. Effective passive strategies include:
Solar Orientation
Passive solar energy can be utilized properly by appropriately orienting the building and minimizing artificial lighting, heating, and cooling needs. This translates into designing with north-facing windows and most of the window area oriented toward the north facade in the Southern Hemisphere.Â
The use of south-facing windows should be reduced. Longitudinal extension in an easterly, westerly direction maximizes northern exposure for a building.
Window Placement
Strategic window placement balances sunlight, ventilation and views without excessive heat gain. Windows placed high on the wall bring in more light and less solar heat. Horizontal shading and overhangs on north, east and west windows prevent overheating while allowing low winter sun to enter. Minimizing east and west windows further reduces solar gain.
Insulation
Insulating walls, roofs and floors limits the loss of heat and decreases the amount of energy that will be wasted in heating and cooling. It ensures there is no thermal bridging or gaps within the insulation. Some of the high performance insulation types include foam, fiberglass and cellulose. Radiant barriers are beneficial in hot climate where insulate should be based on climate condition.
Air Sealing
Preventing air leakage is one of the most cost effective energy saving measures. Sealing all cracks, gaps and penetrations in the building envelope with caulk, spray foam or weather stripping minimizes air infiltration and heat loss. Perform blower door tests to identify leakage sites. Careful air sealing can reduce leakage by 30%.
Natural Ventilation
Window placements and architectures can also be employed in natural cooling of buildings when there is no need for air conditioning by facilitating maximum cross ventilation and passive air flows. This works effectively especially on weathers with mild climates. Air flows through operable windows, open atria, and vent shafts. Use shutters, curtains, and wing walls to regulate airflow.
Shading Devices
Overhangs, louvers, shutters, or screens permit daylighting but deny direct sunlight exposure. It minimizes solar heat gain and small cooling systems. Shaded horizontally, in a southern window. For east and west sun exposure, vertical fins or louvers. Shading is also possible with trees and landscaping.
Thermal Mass
High thermal mass materials such as stone, concrete and adobe act as heat sinks by absorbing heat during the day and radiating it slowly in the evening when temperatures diminish. It results in the passive heating and cooling effect, thus reducing energy demands.
Green Roofs/Living Walls
Green roofs can act as insulators, contribute to solar heat gain reduction, capture rainwater, purify air by absorbing pollutants. A green roof can lower surface temperature by more than fifty degree Fahrenheit.
Active Building Systems
Active building systems and technology are also important as they form part of efficient modern buildings. High performance options to consider include:
HVAC Systems
Using energy efficient HVAC devices such as furnaces, air conditioners and heat pumps saves on energy needed for heating and coolings. However, some systems and features to consider include right-sized systems such as zone control and programmable thermostats. Compared with a typical HVAC system, geothermal heat pumps may cut down energy by 30-60%.
Energy Recovery Ventilators
Heating and cooling are recovered from exhausted air by ERVs and transferred to incoming fresh air. This saves energy that would be wasted through ventilation. The efficiency of heat transfer in ERVs can reach up to 80%.
High Efficiency Lighting
The modern incandescent LED and CFL light bulbs along with contemporary fixtures having a lighting control are very frugal compared to the traditional one. Previous studies have shown that there has been increased pressure on the environment as a result of these actions. However, Waste is also minimized through the use of daylight and occupancy sensors, which switch off lights where necessary.
Renewable Energy
Grid electrical use is offset by on-site renewable power from solar panels, wind turbines, or any other source. Solar PV panels turn sunlight directly into electricity. Solar therapies involve utilizing the heat from the Sun for both water and space heating. Consider building integrated photovoltaics (BIPV).
Energy Management Systems
These smart building automation systems regulate energy consumption within the entire building depending on occupancy and activity levels. This reduces waste and enhances productivity. Building energy use can be decreased by 10–30% using EMS.
Water Efficiency
The second largest energy user is usually water heating after HVAC. The use of low-flow plumbing fixtures, greywater recycling, and rainwater harvest reduces hot water needs and hence reduces energy costs.
Sustainable Building Materials
Choosing sustainably sourced, low-embodied energy building materials also contributes to energy efficiency:
Locally sourced materials reduce transport energy.
Renewable and recycled materials are better than extraction of new resources.
Responsibly harvested wood has low embodied energy and can store carbon.
Straw bale, adobe, rammed earth and cob construction utilize natural low energy materials.
Avoid materials like aluminum and plastics which require high energy to produce.
Pursuing energy efficiency in architecture leads to lower environmental impact buildings that cost less to operate. While optimal passive design comes first, active systems and renewable energy also play an important role.
 Following the strategies outlined in this article will put architecture firms on the path to greener, more sustainable buildings in Africa and beyond.