Building Physics

From the high rise establishments that paint the expansive London skyline to the new build properties nestled within thriving communities, buildings serve as a beacon of societal needs. The planned and precise architecture of buildings provides shelter and comfort for individuals, as well as meet business agendas to promote modern day living. Additionally, buildings serve a purpose as a form of protection where, according to the World Health Organisation (WHO), the design and construction of buildings is to create an environment suitable for human living:

• more favourable than the state of the natural environment outdoors

• construction and building protects us from:

• extremes of temperature

• moisture

• excessive noise

To sustain these pivotal agendas, a comprehensive analysis of the physical factors within the environment of buildings, including temperature, light and sound are required for design and legislation for a building to function. The field of ‘Building Physics’ primarily addresses these physical factors to innovate ‘multifunctional solutions’, be more efficient, and build upon present designs, which can be adapted for future use. Moreover, the built environment is regarded as one of the biggest carbon emissions on the planet, so using building physics as an early design intervention can reduce energy consumption and minimise carbon emissions. This supports global manifestos of moving towards net zero and decreasing the likelihood of the detrimental effects caused by climate change.

The main components of Building Physics

Building Physics is composed of examining the functions of an interior physical environment, including air quality, thermal comfort, acoustics comfort (sound), and light:

• Air quality: Ventilation is needed for maintaining a safe environment and reducing the quantity of stale air - consisting of carbon dioxide and other impurities - within an interior environment. Air infiltration also contributes to a significant heat loss, where it is important to provide intentional ventilation to increase the efficiency of energy transfers within the building. Thus, good ‘airtightness’ of a building fabric, which can be considered as the building’s resistance to unintentional air infiltration or exfiltration, can enable planned airflows for ventilation.

  
  

• Thermal: The biggest influence within the field of Building Physics stems from an understanding of heat conductivity depending on the density and moisture content of the material, as well as heat transfers - conduction, convection, radiation and transition - to determine the suitability of materials used for construction. For example, a material such as a solid wood panel for walls and ceilings is favourable as it can be installed in layers, providing even temperature fields across the surface. It is important that a building has the ability to isolate its environment from external temperature conditions and have the correct building envelope - a barrier that separates the interior and exterior of a building.

  
  

• Acoustics: A regulated control of sound within buildings contributes towards maintaining habitable conditions for building users to make sure that sound is loud, undistorted, and the disturbances are reduced. Acoustics can be controlled and modified through material choices, such as installing sound-absorbing material. These materials can be adapted to reduce sound leakage, which are common in air openings, such as ventilators and doors, that are more likely to transmit sound than adjacent thicker walls.

  
  

• Light: Light provides an outlook of viewing an environment in an attractive manner, particularly using daylight as a primary source of enhancing the exterior of a building, whilst also functioning within a building. One strategy used to fulfil the purpose of light in buildings is designing windows for the distribution of daylight to a space. The window design has a divisive effect on the potential daylight and thermal performance of adjacent spaces, so it needs to be closely checked using the standardised methods, in order to be suitable for use. Additionally, as windows are exposed to the sky, daylighting systems can adapt windows to transmit or reflect daylight as a function of incident angle, for solar sharing, protection from glare and redirection of daylight.

Overall, a key objective of sustaining a safe and eco-friendly building is to ensure that the space has proper heat and humidity aligning with a suitable degree of acoustic and visual comfort in order to sustain the health of the people using the building. Particularly within modern society, a combination of Building Physics principles and digitalised software, such as Building Information Modelling (BIM), can enhance the design process of a building to provide healthy environments for generations to come.

Written by Shiksha Teeluck

REFERENCES

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