Proper natural ventilation is one of the first considerations while designing a home. Building orientation and a well-studied openings layout would promote an effective airflow through the space (cross ventilation, cooling towers). Implementing a functional hybrid ventilation system indoors would contribute to the dilution of some contaminants.
Along with designing a proper and well-controlled aerated dwelling, the architect should consider managing building air leakage by maintaining a stable indoor air pressure. Even though natural ventilation is important, it also entails that whatever air is lost must be replaced to have a neutral indoor/outdoor air pressure. It is crucial not to allow unchecked air infiltration as this would potentially bring in additional pollutants.
Despite the fact that natural ventilation is generally preferred as it is considered to be CO2 free and that most standard mechanical systems use lots of energy, risks could arise through unstudied natural air renewal in the home as outdoor emissions such as traffic pollution and other micro-particles might be brought inside. Isolating connecting spaces is a manner of minimizing the stack effect. Disconnecting building spaces and compartmentalization is another consideration while designing the project.
In addition to the above, the most effective means would also be to implement smart mechanical ventilation/air-conditioning systems with proper filtration and heat/cold recovery. Complementary to natural ventilation, artificial indoor heating and cooling systems could be equipped with specific filters that would reduce the rates of airborne particulates. Bearing in mind that standard fiberglass panel filters are not always most effective as the recommended Minimum Efficiency Reporting Value or MERV should be at 8 and higher (according to certain standards) whereas typical home filters are at 4 or 5. Proper filters are generally not adaptable to all standard ventilation systems and would require constant upkeep.
Effective ventilation and filtering standards can also be reviewed through the Science for Policy report by the Joint Research Center (JRC). It is an informative European standards base to revert to as it introduces the HELTHVENT WP5 Report (2012) which assesses ventilation standards related to Indoor Air Quality and compares them between 16 countries. It is an especially important document to follow up on mechanical ventilation filtering recommendations which are still not too commonly applied in European dwellings.
Another highly important step would be to control the humidity and promote de-humidification. This begins by having a dry construction process including steel or timber framing. A dry foundation and building envelope are key to maintaining a controlled humidity rate that would be comfortable to occupants yet inhibiting the growth of molds or other pollutants. Seeking dry construction and finishing material is also a good step to promoting a healthy indoor air quality.
Finally, one of the most effective ways to mitigate the propagation of indoor air contaminants is by choosing the best material. It is possible to reduce and remove pollution sources. This can be done by using non-toxic modern materials that are purposely created for safe indoor constructions and use. Seeking Green labeled or Health certified items is a good solution to diminish indoor air polluting. Designing buildings and homes with new technology manufactured items can also contribute to much-coveted certifications like BREEAM, LEED, and WELL (rating systems).
Materials such as the Activ'Air® ceiling and plasterboard are even contaminant capturing and dilute up to 70% of VOCs found indoors. They offer a passive and therefore long-lasting technology that would not deploy the captured gases regardless of the temperatures. They require no maintenance and regulation and would, therefore, be more effective in reducing formaldehyde than additional ventilation.
Their practicality also lies in the fact that they are set into the base of the building or interior, as opposed to superficial finishing material (ex. Coatings) which would be more prone to damage and do not offer the same purifying functions. Note that the Activ'Air® panels are just as effective through layers of water-based, acrylic, or epoxy paints and breathable wallpaper (tested in Eurofins and VITO lab to assure the audience of third party validation inc. Conforming to EN 16000-23). Going for such smart materials would also allow flexibility in creating aesthetically pleasing and clean homes. Noting that functional and healthy spaces should not necessarily look boring or sterile.