SPONSOR CPD PROGRAMME Continuing professional development (CPD) is the regular maintenance, improvement and broadening of your knowledge and skills, to maintain professional competence. It is a requirement of CIBSE and other professional bodies. This Journal CPD programme can be used to meet your CPD requirements. Study the module and answer the questions on the final page. Each successfully completed module is equivalent to 1.5 hours of CPD. Modules are also available at www.cibsejournal.com/cpd Evolving standards and ventilation methods in homes This module considers revisions to Building Regulations in England for ventilation that set the path towards the Future Homes Standard Following the recent consultation document on the England Future Homes Standard, the UK government introduced revised England Building Regulations in December 2021, with the interim aim that new homes planned from mid-2022 will include adequate ventilation as well as producing 31% fewer emissions. As part of the package of new regulations, there was a separation of the previous Approved Document (AD) F into a new volume 1 for dwellings and a new volume 2 for buildings other than dwellings. This CPD will focus on the provisions developed to help ensure suitable ventilation for new homes. Inadequate ventilation in homes will produce a miscellany of effects, ranging from the immediate manifestations of condensation, through to the undesirable impacts on the occupants from a cocktail of airborne contaminants. These may be emitted from the fabric and furnishings, as well as resulting from the everyday processes and products used when living in the space. Many impacts will be challenging for building occupants to identify, but a poorly ventilated home can directly adversely affect health through poor indoor air quality (IAQ) and create delayed, possibly long-term, problems such as mould. This is starkly illustrated in Figure 1, and frequently cited in cases considered by the Homes Ombudsman1 (although significant numbers of mould cases result from, in part, deficiencies in the building construction or maintenance procedures). There have been many studies and reports that have contributed to the knowledge and understanding of the role of building air tightness and ventilation strategies on building performance. Work undertaken by Crawley,2 based on the airtightness of newly constructed UK dwellings (investigating a large dataset collected to meet the requirements in the Part F 2010), found that the ventilation strategy appeared to make little difference to the airtightness of homes. For dwellings featuring mechanical ventilation with heat recovery (MVHR), the results suggested that infiltration levels are too high to maximise the energy savings; and for those naturally-ventilated homes, there may be air quality issues. The overall data indicated little practical difference between houses built for MVHR and those for natural ventilation with both sets hovering around the air tightness figure of 5m3.m-2.h-1 @ 50Pa. In that same work, there were some disappointing findings (drawn from an earlier dataset) that might be reasonably interpreted as indicating that many new homes were caulked up for the purposes of meeting an airtightness test rather than being inherently designed and constructed to perform effectively. Crawley concluded that coupling airtightness design and ventilation strategy can reduce a dwellings energy demand and can support achieving the required energy performance rating. In 2016, Zero Carbon Hub (ZCH) published3 an informative catalogue of real-world observations that, despite the sad demise of ZCH, lives on as record of deficient home ventilation installations. This includes examples of the number and performance of installed trickle ventilators not working in harmony with the installed systems (that is, natural, mechanical or MVHR); illustrations of excessively long, poorly supported, flexible ducting that inevitably leads to higher www.cibsejournal.com April 2022 61 CIBSE Apr 22 pp61-64 CPD 193.indd 61 25/03/2022 17:41