Building standards in ventilation
A code is a law or regulation that sets forth minimum requirements for the design and construction of buildings and structures. These minimum requirements, established to protect the health and safety of people, attempt to represent society's compromise between optimum safety and economic feasibility.
Codes and standards
In the common lexicon of codes and standards development, and especially in the various international arenas, the term 'standards' is most commonly used to characterise all the various types of standardising documents (i.e., codes and guidelines, building standards, guides, certifications, policies and construction regulations).
A building code (also known as building control or building regulations) is a set of rules that specify the standards for constructed objects such as buildings and non-building structures.
Building codes are generally intended to be applied by architects, engineers, interior designers, constructors and regulators but are also used for various purposes by environmental scientists, real estate developers, manufacturers of building products and materials, facility managers, tenants, and others.
All of the above are a set of rules that specify the standards for constructed objects as buildings — regulating their design, construction, maintanence, and/or operation.
Why do we need building standards?
Codes and standards serve many purposes but foremost is their contribution to the overall betterment of civilization. Their role is particularly important as we work toward the challenges of a safer and more cost-effective built environment.
In many ways, today's world is complex, and codes and standards provide a point of measurement to simplify our lives. In this sense, codes and standards provide the practical foundation for a better tomorrow.
Building codes have to address a myriad of new technologies and design concepts and have expanded beyond health and safety requirements to include other societal values such as accessibility, energy efficiency, indoor air quality, and sustainability, and many more.
Role of standards in the built environment
Although building codes provide much focus, a variety of other related codes also readily serve the built environment.
Especially, the building standards with regards to ventilation desribe various criteria for levels (i.e. indoor environment and comfort), for design (i.e. buildings, materials and systems) and performance (i.e. energy, environmental).
Also, the purpose of the standard is to ensure that ventilation systems are designed, installed, and can be operated and maintained in a technically, hygienically, and functionally sound manner, e.g., considering comfort and energy efficiency.
Requirements in building codes
Building codes typically contain two types of requirements — prescriptive and performance based. However, a third type of requirement is gaining traction - outcome-based.
Prescriptive requirements provide minimum standards for building materials, products, systems, etc. In a way, they stipulate specifically what to provide and often represent a checklist of items and the minimum acceptable specifications for those items.
In contrast, performance-based requirements set a desired end state and do not provide minimum characteristics per se — they set the desired result without specifying how to achieve that result. In most instances, a measure of achieving the desired result is based on the anticipated results associated with following the prescriptive requirements.
Gaining attention is the outcome-based requirements, where the performance outcome is established, it is not aligned with any particular prescriptive provisions and compliance is verified after rather than before occupancy.
Reduce energy and preserve indoor environment in buildings
Building codes are important for reducing energy use and preserving indoor air quality. In general, the primary ways of conserving energy and preserving air quality in buildings involves:
Efficiency — improving the energy efficiency of equipment and appliances, and optimize the use.
Energy — improving the thermal performance of the building envelope and reducing air change rates to minimize the energy used to condition the indoor air.
People — and thus providing adequate indoor air quality and supply sufficient outdoor air to dilute indoor-generated contaminants.
Standards development and future issues
Despite the slow process of the codes and standards development, building codes have prompted and expanded focus on several issues, for example, the enlarged focus on sustainble and healthy buildings leading to the development of new standards with focus on achieving more than minimimum requirements.
As the building industry moves from the achievement of design criteria to the measurement and verification of actual performance, codes and standards are being focused on commissioning and operations and maintenance and activities and occupancy.
Outcome-based codes have been identified as a potential new methodology for achieving specific levels of performance. Outcome-based codes establish a target level and provide for regular measurement and reporting to assure that the completed building performs at the established level, especially addressing post-occupancy compliance.
Future challenges
The building design is climate dependent
As climate conditions change, existing housing built to a previous standard may experience serious indoor air problems, because either the building envelope or provisions for ventilation, or both, may prove to be inadequate.
Thus, adapting to continuous change may require new and more 'forward looking' framework, and an investment in increased envelope protection and greater adaptability of systems (e.g. balanced ventilation systems tend to be more adaptable, but also cost more).
Focus on balancing energy and indoor air quality
In many codes, the focus is to minimise energy use under the constraints of providing 'minimally acceptable' indoor air. In other words, indoor air quality is being squeezed to its 'minimally acceptable level' while energy conservation has become the objective to maximise.
So there is much greater probability for poor indoor air quality if building code enforcement leans too heavily on the side of energy conservation and thus endangering the building occupants.
It takes several years to implement the new codes
There is a time delay between the time a code is issued, and the time states and communities implement and update their codes. Therefore, the risk is that the issues and solution is no longer applicable.
Indoor air and health problems are becoming more vulnerable during this adjustment period than they have been in the past. Thus, as tightening of building envelopes continues, ventilation requirements may have to play catch up, and homes in the interim will likely be under-ventilated.
Lack of an educated public
The indoor climate is more satisfying to occupants when they can control it, which is why 'occupant control' is important. However, the general public is not very knowledgeable about their role in protecting the indoor air quality in buildings.
The big role plays the public's perception about ventilation and strong public education is needed to educate about better insulation and tighter windows and proper mechanical ventilation usage — thus leading to education about energy conservation and the need for good indoor air.
Building standards throughout the world
Standards are the distilled wisdom of people with expertise in their subject matter, for instance — quality, environment, health & safety, energy, food and IT security, etc. Here is the list of a few organisations dealing with standards throughout the world — with focus on ventilation and indoor environment in buildings:
EN standards in Europe (www.en-standard.eu)
ASHRAE Standards, mainly in the USA (www.ashrae.org)
Note that these are just examples and we recommned broader search.
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Find out more from external experts
Why We Ventilate Our Houses: An Historical Look
Nance E. Matson and Max H. Sherman
Lawrence Berkeley National Laboratory, 2004
The main objective of building standards is to attain minimum standards of safety and general welfare and health of the inhabitants of a building.Anonymous