Case studies

• The impacts of the built environment on human health
• The impact of COVID-19 lockdown on household indoor air quality and windo operation behaviour
• Operational performance of buildings
• Light and Green Roofs
• Home as a place of rest and work: the ideal indoor soundscape during the COVID-19 pandemic (and beyond)
• Reduction in UK carbon emissions through use of white light for street lighting

The impacts of the built environment on human health

 

Dr Clare Heaviside is based at IEDE and funded by a NERC Independent Research Fellowship, investigating the impacts of climate and environmental change on health.

Climate change affects human health directly, through changes in temperatures and increased frequency of extreme weather events, but also indirectly, through modifications to the environment which affect our exposure to things like air pollution and infectious diseases. Clare is particularly interested in the urban environment, heatwaves, air pollution and the urban heat island.

Cities are generally a few degrees warmer than rural areas, and this can have particular impacts during heatwaves, when overheating leads to increased risk of heat-related illness and even death. The urban heat island also interacts with local air pollution, particularly during heatwaves.

Since climate models tend to be based on global simulations with coarse resolution, the impacts of cities on local weather can be difficult to determine. Clare uses higher resolution, regional models, which can simulate meteorology at the regional or city scale, to calculate the impacts of the built environment on human health, for example, the number of heatwave deaths attributed to the urban heat island effect. Protecting public health in future will mean effective adaptation methods such as increased greening or introducing reflective building materials in cities.

The project, HEROIC: Health and Economic impacts of Reducing Overheating in Cities, of which Clare is PI, investigates the relative impacts of different city level adaptation strategies in terms of costs and benefits to human health, to provide evidence for climate change policy makers.

The impact of COVID-19 lockdown on household indoor air quality and window operation behaviour

The Covid-19 outbreak has resulted in extraordinary patterns of home occupancy, whose implications for indoor air quality (IAQ) are unknown. Funded by UCL’s EPSRC IAA and CIBSE, Dr Farhang Tahmasebi and his team at IEDE are studying 8 London flats to find out if during the Covid-19 lockdown (a) IAQ in the monitored flats has deteriorated, (b) the patterns of window operation by occupants have changed, and (c) a more effective approach to natural ventilation could enhance IAQ.

While basic information on occupancy and ventilation patterns is gathered through semi-structured interviews, a one-year long monitoring campaign ran by IEDE (covering indoor and outdoor air temperature, relative humidity, CO2, TVOCs, NO2, PM10 and PM2.5 along with operation of windows by occupants) allows the research team to analyse the impact of Covid-19 lockdown on IAQ.

Furthermore, building thermal performance models populated with the monitored occupancy and window operation data serve to investigate the implications of alternative ventilation strategies for indoor air quality. An initial analysis of the collected indoor environmental data demonstrates significantly higher CO2 and PM10 concentration values during the lockdown as compared with the pre-lockdown period. Notably, the monitored data suggests that, despite the higher occupied hours, occupants have relied less on natural ventilation across the studied flats. The different pattern of window opening and closing is particularly evident in terms of the average duration of windows open state, which is noticeably shorter during the lockdown period.

Operational performance of buildings

Research from UCL IEDE has formed the basis of the recent publication of four Technical Memoranda by CIBSE (Chartered Institution of Building Servies Engineers).

A major concern regarding the built environment is the performance gap between design and operation. This series of Technical Memoranda and its companions aim to provide detailed insights into operational building performance, not only to building services engineers but also other stakeholders, such as architects, contractors, client bodies, students, and users who have an influence on the design, construction, and facilities management outcomes.

A primary requirement to address the performance gap is the collection of operational performance data, which can be fed back to design teams to both diagnose issues with the current design but also to help ensure that lessons are learnt, and future designs improved.

There are many facets to the performance gap, not least the segmentation of disciplines involved in the building life cycle stages. Traditionally, designers, engineers, and contractors are all involved in the building development process, but disband once the building is physically complete, leaving the end-users with a building they are unlikely to fully understand. Gathering more evidence on both the performance gap and its underlying issues can provide insights into feedback mechanisms and prioritize principal issues. It can also help policy-makers understand the trend of energy use and indoor environmental quality and support the development of regulations. Finally, operational data are valuable to facility managers and building users in order to efficiently operate their buildings.

Lighting and Green Roofs

Green walls in buildings are becoming more popular, however lighting them can be a bit of a problem.  In the past most people have used horticultural lighting techniques to promote plant growth. The problem is that plants under this sort of light do not look that good and tend to grow quite quickly.

To investigate the problem we have been running an experiment using three identical living walls with six different plant species: Aspar D Sprengeri, Asple Antiquum, Hedera He Wonder, Maranta Fascin, Nephr Ex Emina and  Radermachera Sinica. Each wall was illuminated with three different colours of white LED light sources namely warm (3000K), neutral (4000K) and daylight (5600K) for a period of 5 months.  All of the sources had good colour rendering properties.  
 
Plant health in terms of growth patterns was monitored and documented at the end of the 5-month period to assess the biological effectiveness of the illumination.  
To assess which light source was the best in terms of how the wall looked 106 participants viewed the walls under different light sources and were surveyed in terms of preferences for naturalness and visual appeal using questionnaires to assess the visual effectiveness of the illumination.  

Home as a place of rest and work: the ideal indoor soundscape during the COVID-19 pandemic (and beyond)

Due to the COVID outbreak and consequent lockdown situation, home is being experienced as both a place of rest and work. With the purpose of investigating how the acoustic environment and building features affect people’s quality of life and work, an online survey will be developed and administered in two countries, UK and Italy, representing different climatic zones and ventilation habits.

The questionnaire would employ closed and open-format questions to be coupled with qualitative analyses and soundscape measurement tools in order to i) get insights into how the stay-home period has changed the acoustic experience at home, ii) inform about people’s expectations in terms of their ideal indoor soundscape while relaxing and working at home, and iii) highlight cross-cultural differences between UK and Italy.

Lessons learned from this lockdown situation would inform about actions to improve the built environment in order to provide high-quality living (and working) home environments beyond this COVID-19 pandemic.

Reduction in UK carbon emissions through use of white light for street lighting

Our research has led to the adoption of white light throughout the UK, enabling an energy saving of 30–40% while providing better quality street lighting. Conservative estimates suggest that this changeover to white light saved 113 GWh of electricity in 2012, and thus reduced the UK emissions of CO2 by 45.5 megatons.

The original research was funded by ESPRC. The results of the work has kick-started a much closer examination of the needs of pedestrians on streets at night. Work in this area is continuing in the EPSRC-funded MERLIN project.

For more information on how we have helped reduce UK carbon emissions through use of white light for street lighting, please contact Peter Raynham.