With humans spending 90 percent of our time indoors, our individual health is directly tied to the health of our buildings. Healthy Buildings, we believe, are at the nexus of global health and sustainable development goals.

A robust body of research produced over 40 years on the importance of the indoor environment has revealed what the Harvard School of Public Health calls the 9 Foundations of a Healthy Building: ventilation, thermal health, air quality, moisture, dust and pests, safety and security, water quality, noise, and lighting and views (9 Foundations of a Healthy Building, 2016). For example, poor indoor air quality and ventilation are associated with increased sick building symptoms, altered infectious disease transmission, and reduced cognitive function. Unfavourable thermal conditions have been found to negatively impact eye and throat irritation, headaches, heart rate, respiratory symptoms, mood, and thinking and performing.

When considering any retrofit project, where the existing building fabric is being impacted, you must be cognisant of the laws of building physics in that you can’t really manage heat without also managing moisture!!

While the industry, supported by government policy, tends to focus exclusively on energy conservation, the management of moisture is an equally critical part of the overall strategy, yet is either, at best superficially addressed, or at worst ignored. The risks to health and the fabric of the building are as a result elevated. The regeneration of existing buildings needs to understand and be sympathetic/respectful to the original design and engineering intent. Failure to do so can lead to many unintended consequences, that may impact IAQ and energy efficiency or lead to Sick Building Syndrome.

Moisture in building fabric is a key driver of energy loss. Wet materials transfer heat much quicker than dry materials. Tests have shown that a damp content of 5% in a plain brick wall can lower the insulation performance of that wall by up to 50%.

Heat and moisture dynamically interact in every nook and cranny of our buildings, every minute of every day. Hygrothermal movement (hygro for moisture, thermal for heat) is driven by the laws of physics and is predictable in uninsulated buildings. However, as we air-seal, vapour retard and insulate, making it difficult for heat and moisture to flow through the building envelope we lose the predictability of the original design intent thereby increasing the risk of failure.

The simple question is “how do we keep the weather out and the heat in?” while ensuring that the IAQ and space heating comfort are optimised?”

Answer:

• Informed design that takes a holistic approach to thermal comfort and moisture management. “Whole” Building approach to design with systematic on-site observations of the property, monitoring RH levels, etc
• Provide a suite of solutions that offer best option for success. Eg Super Hydrophobic coatings for solid wall construction and ThermaClad EWI with a drainage cavity for more modern construction methodologies.
• Provide performance guarantees
• Explain both maintenance and ventilation requirements to the Occupants