On July 25th Architecture & Design Scotland in collaboration with Mackintosh Environmental Architecture Research Unit (MEARU) from Glasgow School of Art hosted a CPD event on occupant comfort and wellbeing in housing.

What do we mean by occupant comfort and wellbeing, and most importantly how can we measure it?

A holistic approach to wellbeing focuses not only on physical health and absence of disease but on mental and social health as well. In the context of buildings, apart from good materials, effective insulation, ventilation, and access to daylight; a healthy home is designed to provide a sense of comfort, relaxation, security, opportunities for family interaction, social engagement, and much more.

Occupant comfort and wellbeing were measured by MEARU through both qualitative (interviews with occupants and building users) and cross-analysis of quantitative findings from data sources. It is worth noting that quantitative findings are usually based on averages and these can often be misleading unless they are combined with qualitative findings. A characteristic example of this is the research undertaken in overheating.

Janice Foster and Laura Barnfield, who delivered the talk, introduced the three main steps of the process they had undertaken: Monitoring, Analysis, and Communication. Through the use of Building Performance Evaluation (BPE) existing buildings were investigated to establish whether they performed as intended, provide healthy environments, and how their design can be improved. These steps were utilized in one of the most recent projects MEARU were engaged in for the Innovate UK BPE programme. 26 dwellings of different design and construction materials were monitored, including sheltered housing, flats, 1 and 2-storey houses, new tenement buildings, and Passivhaus dwellings.

What exactly do these three steps include?

Step 1: Monitoring, testing, and evaluating.

The core criteria that were monitored through a period of two years were:

1. a) the performance of building fabric and systems,
2. b) the indoor environmental conditions,
3. c) the occupant comfort,
4. d) the energy usage, and
5. e) the performance of ventilation strategies.

Step 2: Analysis

The key information for each building was identified from the data collected in each of the above categories where they were analysed and tested against regulatory standards and the stated design targets.

Step 3: Communication

The final part of the strategy is for the improvement of occupant comfort and wellbeing and closing design loops. Feedback is provided to occupants, clients and industry. This way BPE brings tangible results on how to implement and make use of new technologies in everyday life.

Three recurrent issues that affected the occupants’ comfort and well-being:

1. Overheating

Part of an occupant’s wellbeing depends on the ability and affordability to maintain their indoor temperature to a desired level of comfort. In the UK 2000 premature heat-related deaths are recorded every year, with the numbers expected to rise in the near future due to climate change. MEARU monitored the internal temperature in each of the homes and compared the results to the Passivhaus overheating criteria.

An interesting pattern emerged: there were homes that were considered to have overheated throughout the whole year, even during winter months. The in-depth investigation that followed revealed several reasons behind this pattern in some of the homes, these include:

• In sheltered homes, occupants often had trouble accessing windows due to mobility issues.
• Many occupants did not know how to operate their heating systems.
• Controls for heating were installed in places that were often difficult to reach.
• Contractors had misunderstood design concepts (e.g. incorrect placement of insulation in sunspaces).
• Many high-level windows in sunspaces had missing handles and these, therefore, could not be used for ventilation.

2. Indoor Air Quality

As buildings become more airtight and allow less infiltration to improve energy efficiency, indoor air is replaced at a slower rate. This means that without proper ventilation there is a risk of high pollutant concentrations in the indoor environment. These are released by a number of sources including: building materials, furniture and products, as well as high humidity.

MEARU monitored carbon dioxide concentrations (CO₂) in the homes and used this data to indicate whether indoor air quality was adequate. The monitoring showed that although the average concentration of CO₂ was often below accepted threshold levels of 1,000ppm, there were high peaks where the threshold levels were exceeded, often in bedrooms where people are sleeping. These CO₂ peaks also coincided with peaks in formaldehyde and particulate matter.

Mould growth was another common occurrence especially in houses that had underperforming extract fans and where occupants were frequently drying laundry indoors.

3. Quality of Space

There were many quality spaces in the monitored buildings, including areas with plenty of natural daylight and high ceilings. However, problems often existed simultaneously in other areas such as: draughty rooms, limited bedroom and kitchen size, absence of space for laundry drying, impact and airborne noise originating from neighbouring flats, limited access to services (e.g. gas meter), inadequate ventilation in kitchens and bathrooms etc. These issues tended to disrupt the occupants’ everyday life and noise issues ultimately affected neighbour relationships and caused conflict in new communities.

At the same time, some successful examples were recorded. A number of buildings had an overall positive impact on their occupants, with some reporting improved relationships with friends and family and improvement of their mental health.

What was the key conclusion of this event?

The overarching conclusion of this talk can be summarized in the phrase: Housing is more than energy consumption.A successful home not only allows people to be physically and mentally healthy but also adapts and responds to changing requirements, provides opportunities to restore, uplift the spirit and make people happy.

Further reading on building healthy environments:

Online resources

UK Green Building Council https://www.ukgbc.org/

Green Building http://greenbuilding.co.uk/

SUSTAINABLE RENOVATION improving homes for energy, health and environment – Chris Morgan  https://www.seda.uk.net/design-guides

Design and Detailing for Toxic Chemical Reduction in Buildings – Howard Liddell, John Gilbert, Sandy Halliday https://www.seda.uk.net/design-guides

Dormont Park Passivhaus: The tenants experience https://www.youtube.com/watch?v=wcrW5x4NJbk

Books

Sustainable construction – Sandy Halliday

Sustainability: RIBA Plan of Work 2013 Guide – Sandy Halliday, Richard Atkins

Sustainable Housing Design Guide for Scotland – Fionn Stevenson, Nick Williams

SUSTAINABLE RENOVATION improving homes for energy, health and environment https://www.seda.uk.net/design-guides