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Free, Innovative & Sustainable Techniques are Cooling Houses with Tin Roofs by 10°C

Knowledge-centric solutions hub, cBalance curated the ‘Informal Housing Thermal Comfort’ project. It encourages participatory action from poor households to build thermally comfortable humane structures for them to live.

Free, Innovative & Sustainable Techniques are Cooling Houses with Tin Roofs by 10°C

This article is part of a deep dive to celebrate Environment Day by highlighting individual and community action that leads to large scale impact on the planet. ItStartsWithMe is the second chapter of ‘Shaping Sustainability’, an exclusive series by The Better India, to give our readers an in-depth understanding of how Indians are making sustainability a priority in all walks of life. Find more stories from the series here

“It is difficult to sleep due to the heat, which gets worse during power cuts. I also have a blood pressure problem which gets difficult to manage during summers due to the discomfort caused by the lack of ventilation in my house,” says Vijayalaxmi from Bengaluru.

She is one of the innumerable people battling heat stress under poorly ventilated, heat-absorbing tin-roofed house structures of India’s marginalised urban settlements. Homes in these settlements mostly have ceiling fans which support thermal comfort needs in a minimal capacity. These houses are also susceptible to frequent power cuts.

At the other end of the spectrum are residents of affluent urban neighbourhoods who live in relatively well-ventilated houses in addition to owning Air Conditioners. They also have backup power sources to support them during rare instances of power cuts. This glaring energy inequity in urban areas demands scrutiny, given the fact that a typical one-tonne, split-AC in India consumes as much power as 25 ceiling fans.

Rising temperatures fuelled by the escalating climate crisis and the energy inequity scenario warrants moving towards a diversity of thermal comfort interventions which are both sustainable and affordable.

While there have been interventions—such as ‘cool roofs’, which involve painting roofs white to reflect heat, and those such as the ‘dormer window’, which support creating a gateway for hot indoor air to escape outdoors—cooling mechanisms that focus on creating a barrier between the suns radiation and a tin-roofed house are rare. Recognising the need to work on experimenting with such mechanisms and some already existing ones with inhabitants of informal settlements, our team at cBalance curated the ‘Informal Housing Thermal Comfort’ project.

Most thermal cooling techniques as part of this endeavour focus on experimenting with such mechanisms. A vital element of this experimentation was to build on internal research findings and ‘co-create’ contextualised techniques with informal housing communities.

Initial exploratory data collected on thermal conditions in a few informal structures in Mumbai and Pune indicated roof surface temperatures above 50°C even when air temperatures were a moderate 30°C. These were measured after informal conversations with a few women inhabiting these settlements in the year 2017 after they shared the perils of heat stress they endure in their tin-roofed houses. Since we had a certain amount of pre-existing experience with working on sustainable cooling, we were catalysed to embark on a thermal comfort journey with those impacted disproportionately by rising temperatures. This journey commenced with researching about and installing Alufoil radiant barriers in a few structures including the homes of the women we spoke to, as an experiment. An average temperature drop of 8.5-10°C was observed after the installation. While research on thermal comfort techniques in informal settlements commenced around 2017, the endeavour was initiated as a grant-funded project centred on co-creation in October 2020 with support from Ashden.

Why ‘co-creation’ is essential for informal housing endeavours

Free, Innovative & Sustainable Techniques are Cooling Houses with Tin Roofs by 10°C

A vital factor that must be considered while contemplating interventions in informal housing communities is the exclusion of inhabitants from participating in the decision-making. Such an approach, more often than not, leads to interventions that are not suited to people’s context and fail to serve their needs. Additionally, once a project implementation entity dissociates from a community, the skills and knowledge they bring to the table exit with them. A ‘top-down’ approach to intervention is therefore hardly sustainable.

For instance, imagine an external entity enforcing that a cooling material you are oblivious of, be installed in your house or insist that you agree to have a part of your roof cut to install a new intervention you have never seen or heard about previously. How comfortable would you be with such an imposition? We guess, not very comfortable.

Further, imagine a scenario where once the installation is complete, the external entity cuts ties with your family and you face issues with maintaining the installation in the long term. And what if someone else wants to replicate the installation in their home?

Therefore, it makes sense to work ‘with’ people and ‘co-create’ interventions with them rather than imposing solutions.

Understanding the problems

Free, Innovative & Sustainable Techniques are Cooling Houses with Tin Roofs by 10°C

The ‘Informal Housing Thermal Comfort’ project is grounded in ‘participatory action’ for the ‘co-creation’ of sustainable thermal comfort materials and mechanisms that can be retrofitted in tin-roofed house structures. The intention was to approach this endeavour as an ‘experiment’ given that many ideas we had been researching hadn’t been physically tried and tested in the contexts we were hoping to work in.

The project was initiated in Pune and Bengaluru, where we collaborated with two grassroots organisations; MASHAL and Hasirudala. The organisations supported rapport building with the communities of Jyothipura in Bengaluru and Shindevasti in Pune. They served as a bridge between our team and the communities with whom they had an already established relationship of trust due to past and ongoing development initiatives.

Community engagement was initiated through household surveys and ‘listening workshops’ which revealed heat stress-related issues community members battle with, in addition to other roof related issues they experience across different seasons. Few of the many issues that were shared included; difficulty in performing household chores such as cooking, due to unbearable indoor temperatures by women who bear the brunt of household responsibilities and children finding it difficult to focus on studies. Health issues such as headaches, dizziness and skin irritation were mentioned among a range of ailments. Sleep deprivation was a major concern for residents since the indoors cool around midnight or even later, depending on the outdoor temperature in addition to the heat generated from indoor activities. Another major house structure related issue residents expressed in addition to heat stress was the issue of water leakage during the rains. The necessity to ‘listen’ to residents and ensure that addressing one issue does not aggravate another was enunciated through interactions with community members during the ‘listening workshops’.

Residents also shared already existing mechanisms to deal with the issues they were experiencing. A few heat stress battling mechanisms people were already working with involved; sprinkling water on tin roofs, placing hay from cattle sheds on the roof, placing thermocol sheets/foam rolls on the underside of the roof, wiping the fan with a wet cloth to trigger cool air circulation among other mechanisms. These learnings foregrounded the importance of acknowledging and building on the already existing repository of knowledge of those who are marginalised from decision-making processes.

This exercise was followed by a ‘participatory design workshop’. This was a space for residents to share their opinions and suggestion on a few designs comprising a range of materials that had been researched by the projects design team (which also included students from local architecture and engineering colleges). These materials and designs included ‘alufoil’, eco board, glass wool, water-filled PET bottles, rooftop gardens and dormer window. These workshops gave the design team a whole new perspective on the initially suggested designs, as residents highlighted critical issues e.g., rodents that frequent homes could nest in and also damage certain installations. Animals like cats, goats and dogs walk on roofs and could damage solutions installed over the roof. There is a danger of solutions triggering fires if they get in touch with overhead electrical wires. Residents also rejected the glass wool solution outright based on experiences they had with the material while working as factory helpers. This helped us realise that while some things might work in theory, they might not work on site. This is when the designs started metamorphosing into people-centric ones. Besides sharing concerns, community members also shared alternatives to refine certain solutions which were considered while finalising designs before installation.

Before commencing installations, residents were assured that our team would be available to cater to any unforeseen issues with the installations and would look into the removal of installations, if needed and requested, too. It was also conveyed that they had the choice to say ‘no’ if they were sceptical about working with the experimental designs we had co-created.

Some residents refused to have certain installations retrofitted in their homes and their decision was respected. Additionally, post-installation there were instances where residents experienced water leakage issues during unseasonal rains in Pune and Bengaluru due to certain installations. These installations were removed and the designs were refined for the next set of installations. Overall, approaching both acceptance and rejection by the community in the spirit of learning, helped keep the participatory nature of the thermal comfort endeavour alive.

Further, all residents who embarked on the experimental journey were invited to share their feedback on installations to facilitate the process of understanding the effectiveness of the solutions and refining design elements that warranted refinement. Following this, the designs were worked on and installed in additional 10 homes in Pune and 5 homes in Bengaluru, to observe their efficacy. Critical feedback was sought from residents, again.

Custom-made unique cooling solutions

Ecoboard Chain Sprocket installation
Ecoboard Chain Sprocket (left-open, right-closed) installation

The critical feedback revealed the fundamentality of contextualised intervention. For instance, a woman resident inhabiting a house with a ‘Water Filled PET’ bottle installation in Pune shared, “We used to sit outside the house from 12 pm to 3:30-4:30 pm due to the unbearable indoor heat. However, we can sit indoors now. I used to begin my tailoring work post-4 pm previously, however, I have the flexibility to work whenever I want, now. I can now sew in the morning and evening, both.”

Contrastingly, in a community library in Bengaluru where the same installation has been experimented with, feedback revealed that there is no difference in temperature after the installation. Our NGO partner members who have facilitated the creation of the library space stated, “The indoor humidity is very high and we can’t stay inside for a long time without the fan. The installation is not reducing indoor heat.” Similarly, while residents in Pune expressed that the ‘Wood Wool Panel’ installation (which was used in place of the initially rejected glass wool insulation) was effective, residents in Bengaluru felt that the installation was not supporting with minimising heat stress in their homes.

There were certain installations such as the ‘Alufoil Chain Sprocket’ mechanism installation (a dynamic installation which can be closed during the day to shield residents from the suns radiation and opened at night to allow heat trapped in the house to escape outdoors), which received encouraging feedback from residents in both localities. A resident in Bengaluru mentioned, ‘The use of the fan has reduced after this installation and we can sleep better at night’. Similarly, a resident in Pune mentioned that her family can sleep better after the installation. The diverse experiences of residents with different solutions reinforced the need to co-create contextualised responses to address the issue of heat stress and any other issue for that matter.

Overall, 12 experimental solutions have been installed across 24 structures across Pune and Bengaluru, namely; Water Filled Pet Bottles, Rooftop Garden (Brick Bed), Rooftop Garden (Grow Bags), Alufoil (Static), Alufoil (Pipe Motor), Alufoil (Chain Sprocket), Alufoil (Curtain Mechanism), Wood Wool Panels, Dormer Window, Ecoboard (Chain Sprocket) and Ecoboard (Sliding). The installation monitoring process is continuing with support from thermal comfort measurement devices and feedback based on people’s lived experiences. Relationships with the communities will continue to be maintained in the spirit of partnership.

The larger goal of the ‘Informal Housing Thermal Comfort endeavours is to share finalised co-created designs of effective installations with women’s cooperatives and other interested local entities to build their capacities for fabricating, installing and maintaining thermal comfort retrofits in their communities. While this can support addressing the issue of heat stress it will also support the creation of revenue-generating activities within the communities, thereby enhancing independency.

Additionally, we are also working towards collaborating with more grassroots NGOs and government entities in other cities to facilitate informal housing thermal comfort experimental endeavours.

The magnitude of the climate crisis and rising temperatures necessitates innovation through participatory action. We must walk hand-in-hand and break away from hierarchical and monopolistic structures to manifest a more just world with thermally comfortable humane structures that enable them to live healthy and peaceful lives.

rooftop garden
Rooftop garden grow bags and brick bed installations

(Written by Vivek Gilani and Vinita Rodrigues; Edited by Yoshita Rao) 

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