Exploring DIY urbanism as an unconventional solution for urban climate adaptation

The following results section first reviews how and in what contexts the literature on DIY urbanism has engaged with urban climate adaptation (RQ1). Second, it assesses the potential impacts of urban adaptation-oriented DIY interventions on enhancing outdoor thermal comfort (OTC), mitigating urban heat island (UHI) effects, and improving stormwater management, drawing on analogical evidence from comparable planned examples (RQ2).

Research on DIY-Urbanism for urban climate adaptation

While DIY urbanism is well acknowledged in academic literature, few studies consider climate change and urban climate adaptation. We identified 19 studies that discuss aspects of DIY urbanism with relevance for urban climate adaptation (Table 1). Most studies were case studies, while two reviews were also included^24,40.Only eight studies explicitly examine DIY urbanism in the context of climate adaptation—some motivated by climate change^{27,40,44,45,46,47} and others relevant to local climate^34,48. Most of these studies looked at specific projects, while other studies directly address specific interventions, such as parklets and parking days^40,46, pop-up parks⁴⁸ and guerrilla gardens³⁴. In addition, we found further studies on climate adaptation that examined grassroots initiatives and experiments, which did not fully meet the defining criteria of DIY urbanism^{24,26,32,39,42,49,50,51}, but still seem a valuable addition for the discussions. Those include BUIs, civic stewardship, tactical urbanism and neighbourhood climate actions that also took place partly in public space and unauthorised.

A general challenge of this review was the lack of clear terminology and overlap in the literature. According to our definition, we focused on unauthorised forms of intervention in public spaces, thereby keeping the number of studies manageable. Many interventions, however, exist both as unauthorised DIY initiatives and as authorised projects, such as in urban living labs or urban gardening programs. This overlap makes the separation between considered and unconsidered literature somewhat unclear, potentially leaving out relevant studies that focused on authorised implementations.

Most studies took place in Europe and North America (USA, Canada), while relatively few were conducted in Africa or Asia. The dominance in literature from the Global North as well as the few studies from the Global South is expected according to the global share of academic publications⁵². The scarcity of studies from the Global South is also reflected in a review study about climate governance⁵³. In contrast, to the general share of academic publications⁵², the absence of studies from China is apparent. The reasons for these disparities are unclear and not the main scope of this paper. They might be related to low academic production in this field, other types of reporting or different terms and concepts⁵³. Overall, the governance mode influences the level and motivation of participation involvement strongly⁵³ and thus the emerging and perception of DIY urbanism. Often governmental community participation is restricted culturally, institutionally, socially and in general reduced in authoritarian and military governments⁵³. The geographic context is important, as DIY urbanism may serve as a playful or protest-oriented practice in some regions, but in others, it may address existential needs such as securing property or health. For example, Udelsmann⁴⁹ states in an analysis of Angola and Mozambique that the main challenges regarding climate vulnerability are widespread poverty and the absence of formal adaptation plans at the city level, which lead to improvised interventions, particularly in response to flooding in both private and public spaces.

In most studies, individuals participate in DIY urbanism or grassroots initiatives because they perceive a problem in their local environment^27,34,43. Their participation is primarily motivated by personal concerns rather than political aims or formal climate change adaptation objectives^27,34,43. Although urban greening, in particular, was communicated as motivated by climate change—as in the project examined by Brazeau-Béliveau & Cloutier³⁹—the participants were rarely motivated to get involved primarily because of climate change²⁷.

This makes both the identified problem and the place key factors for the emergence of DIY urbanism. The problem needs to be at an optimal scale, meaning it should be physically and socially tangible⁵⁰. Place attachment is a key factor in local initiatives describing the emotional connections between people and places²⁴. Generally, DIY urbanism thrives in spaces with potential for reuse, like brownfields, car parks, and street sections, often due to perceived planning deficiencies^27,29,33,37.

Another frequently cited factor is local-level involvement and social capacity to act^24,39,51. This becomes particularly visible in Tamminga et al.⁵⁴, who name different types of independent street greening as “convivial greenstreets” and emphasise the social aspects in gardening and greening. Initiatives are more likely to thrive in regions with abundant human and social capital, which enhances residents’ access to necessary resources^24,42,50. Relatedly, concerns regarding inequality have been raised: DIY urbanism may primarily benefit wealthier communities, where residents typically possess the education, social networks, and resources needed to take advantage of such initiatives^24,42.

The type of perceived climate risk can influence the measures and interventions taken, as investigated by⁴⁴. In Accra and Kumasi, Ghana, extreme heat was primarily addressed through personal protection (e.g., wearing hats) rather than DIY urbanism, whereas flooding was often mitigated through infrastructural measures in public spaces (e.g., drainage systems, walls). Additionally, factors such as age and education influenced the choice of adaptation measures⁴⁴.

While local-level involvement is important, BUIs also rely on support from public administration to succeed⁵¹. The availability of institutional capital can have dual effects: a trustworthy and respected government may encourage residents to collaborate, whereas dysfunctional institutions may drive frustrated residents to take matters into their own hands⁴². Moreover, grassroots initiatives also require financial and technical support, as well as agency to persist^24,39. Several influencing factors on their appearance have been detected by previous studies, overall, however, the emergence and the topics of such initiatives remain unpredictable and largely unguided⁴².

DIY urbanism and other forms of autonomous adaptation in public space are not always welcomed and are often discussed controversially and in tensions between neighbours, activists, and local authorities⁴⁵. Due to its “do-it-yourself” nature and unauthorised status, DIY urbanism presents significant challenges for traditional planning and government structures³⁸. DIY urbanism occupies the intersection of formal and informal planning, raising numerous questions about the nature of planning itself—where it takes place, who is involved, and the purposes it serves, as summarised by Vallance & Edwards³⁵. They analyse how tactical urbanism, as an “antidote,” introduces fundamentally new approaches to planning and can create synergies with strategic planning to address its weaknesses, such as long timeframes, lack of control, the need for translation, and implementation challenges. Despite being unauthorised and critical, the activist’s focus lies on a collaborative approach with the city administration²⁷.

The study conducted by Sulatana et al.⁵⁵ analyses green infrastructure in an informal settlement of Dhaka. Here, the institutional vacuum is exceptionally high and leads to tree planting, greened public spaces initiated by non-governmental organisations or community-based organisations.

Even more traditional and less critical approaches, such as BUIs for risk management, are often viewed critically by officials, as pointed out by Thaler & Seebauer⁴². Public administrations and emergency organisations are sceptical about BUI engagement, particularly regarding legal liability, limited competencies, and the potential loss of power and responsibility⁴². In contrast, residents would be willing to take on various responsibilities at all stages of risk management⁴². Conflicts between initiatives and public administrations, as well as a lack of procedural justice, can arise when only certain groups benefit from the adjustments⁴².

While DIY urbanism stems from a motivation to improve the immediate surroundings, from a climate adaptation perspective, the primary interest is whether such approaches can contribute to creating climate-adapted cities. The potential microclimatic effects of these interventions are discussed in the next chapter. In this section, we aim to explore aspects of the evolution of DIY urbanism and its transformative potential for long-term, large-scale climate adaptation.

This review found several success stories where local approaches have led to official, planned adaptation efforts. Caggiano et al.⁴³ analysed the “Love Your Street Tree” initiative in Manhattan, described as civic stewardship by the authors, which is also overlapping with DIY urbanism in our view. The initiative focuses on the caretaking of street trees and aims to increase permeable surfaces for rainwater management, partly motivated by concerns about climate change. Originally an unauthorised DIY movement, the now annual “Love Your Street Tree Day” is held in collaboration with public officials and attracts numerous residents who come together to learn about and care for trees within their communities. Caggiano et al.⁴³ conclude that civic stewardship could play a key role in urban climate governance, given its ability to address both the social and ecological dimensions of urban adaptation. Moreover, the DIY urbanism approach related to rainwater harvesting in Arizona can be considered successful⁴⁵. Originating from unauthorised DIY efforts, they gained increasing attention, engaged a broader community, and generated greater political pressure, ultimately resulting in a political transformation through the institutionalisation of rainwater harvesting⁴⁵. Despite this institutional shift, the authors also note that tensions between official and autonomous actors persist⁴⁵.

Additionally, the mainstreaming of events like “Parking Day,” which evolved into widely accepted parklets, can be seen as a success. The transition from “Parking Day” as a DIY urbanism approach to parklets—now officially developed by many cities around the world—demonstrates that small-scale interventions and creative ideas can have a significant impact on urban climate adaptation⁴⁰. The number of “Parking Day” events grew from one spot in a single city in 2005 to over 900 spots in 162 cities by 2011⁴⁰. This highlights how a small-scale, temporary event or ad-hoc action in public space can spark a change that leads to permanent solutions⁴⁰. The example of parklets also shows how the initially subversive ideas from “Parking Day” were neutralised and co-opted by governments, turning them into official parklets to create “creative cities,” as seen in many cities worldwide today, and thereby change the nature of their initial DIY characteristic⁴⁰.

Moreover, the general experimental setup of testing rather than debating has often proven successful, as analysed for pop-up parks⁴⁸. confirmed that pop-up urbanism can serve as a “proof of concept” for permanent installations by analysing four pop-up parks. These temporary setups provided visible, hands-on experiences that allowed users to directly see and feel the project’s potential⁴⁸. On-site engagement helped residents and businesses better understand the concept and take part in the design process⁴⁸. The pop-up process also eased resistance from groups ideologically opposed to such projects by offering a temporary, low-risk way to experience the benefits firsthand⁴⁸. In this sense, experimental urbanism can serve as an excellent, straightforward, and practical learning approach in the complex and unpredictable planning environment of cities³¹.

DIY urbanism interventions can help establish innovative, sophisticated, low-cost, and creative solutions for urban problems that have been overlooked. DIY urbanism as a citizen-led planning approach can also aid in mainstreaming climate adaptation and bridging the gap between individual and planned adaptation efforts^38,42. Frequently, DIY urbanism is discussed as an opportunity for creating communities, building a sense of mutualism, and fostering social capital. It contributes to the development of bottom-up democracy and the decentralisation of power, which in turn increases the adaptive capacity of communities⁵⁰. In this sense, DIY urbanism aligns with the modern self-conception of planning, driven by proactive and visionary residents³⁸.

Critics argue that there is a shortage of reflective learning—a second-order learning process necessary for broader transformations³¹. The “build-measure-learn” approach in tactical urbanism should go beyond short-term outcomes to emphasise broader, transferable lessons³¹. While local insights are valuable, a stronger focus on conceptual understanding can help apply tactical urbanism more effectively across different contexts³¹.

Despite these potentials, we assume that many initiatives will fade without any lasting impact. When individual interventions are not embedded in broader political engagement or political opportunities, they remain ineffective³⁰. Moreover, this perspective assumes the presence of formal planning frameworks. In contrast, in contexts such as Bangladesh, Mozambique, and Angola, DIY urbanism may represent the only available form of urban adaptation for some communities^47,55.

Potential microclimatic effects of DIY interventions in cities

Having analysed how urban climate adaptation is discussed in the literature on DIY urbanism, we now estimate analogous small-scale urban interventions to evaluate the potential contributions of DIY urbanism to heat reduction and stormwater management in cities. Table 1 summarises nine interventions with the potential to contribute to urban climate adaptation; specifically, enhancing OTC by decreasing heat hazards and biometeorological indices during the day, reducing UHI effects by lowering air temperature, particularly at night, and potentially improving stormwater management by increasing retention or infiltration (see Fig. 3). Many of the DIY interventions align with established and planned approaches to urban climate adaptation. While their specific design and scale may vary, it is assumed that their spatial implementation will predominantly occur at a small scale, given the nature of DIY urbanism (e.g., low-cost, quick-to-implement, and temporary)³⁷. Most interventions involve small additions or improvements to existing urban infrastructure^44,47. also report more basic infrastructure-based interventions, such as bridges and drainage systems for flood prevention in Mozambique, Angola and Ghana, which were not included, because they are highly regulated in many countries.

In the following, we provide an estimation of the potential microclimatic and hydrological impacts of DIY interventions on heat and stormwater management based on analogies from planned interventions. While this method constitutes only a coarse estimation based on current studies in human biometeorology, urban climatology, and urban hydrology, and does not contribute novel findings. It facilitates knowledge transfer and enables readers, particularly from planning and social sciences, to better contextualize and approximate potential effectiveness. Most of the reviewed studies focus on the effects on society and politics rather than on the direct physical impacts. Just a few studies discussed potential effects of heat and stormwater management from the implementation of interventions: Littke⁴⁶ discussed the parklets as a “symbolic shift from pavement to parks”, and estimates a low ecological functionality and warns that they should not be mistaken for actual urban green space. Similarly, although⁵⁴ motivate their work on street greening through climate-responsive urban design, they also assume that individual interventions are unlikely to produce measurable cooling effects. They assume that only precinct- or city-scale implementation can produce meaningful cooling. An observation or simulation for further evidence of these statements was not provided.

Street greening encompasses a range of interventions, from seed bombing and guerrilla gardening to façade-, brownfield-, and tree pit greening⁵⁴. provide an overview of different types and potential microclimatic effects. Here, we considered these forms as introducing or enhancing new herbaceous vegetation or potted vegetation regarding the assessments of its potential effects. Examples such as street beautification in Quebec, small-scale convivial green streets or collective gardens in Montreal primarily used low-growing shrubs or perennials as planting for food production and the enhancement of spatial aesthetics^27,34,54. While low vegetation has a limited impact on thermal comfort indicators such as PET due to insufficient shading², it can moderately reduce UHI effects depending on the scale of implementation. As summarised in other reviews, replacing sealed surfaces with vegetation significantly lowers surface temperatures², and turf grass has been shown to reduce air temperatures by up to 1 K compared to built-up areas⁵⁶. Similar effects for DIY interventions are expected to be smaller and more site-specific. Also, façade green can be implemented, which has a limited effect on OTC and air temperature^5,57,58.

Vegetation can help to regulate stormwater through rainfall interception, infiltration and retention^59,60,61. These effects depend on the type, size, and substrate of the vegetation. Vegetation enhances soil infiltration and water retention due to root penetration⁶². A previous review highlights that this effect is generally stronger in trees than in herbaceous plants, especially those with deep root systems⁶². An observational case-study conducted in Gemany⁶¹ found that grass below trees, similar to tree pit greening, can have a greater impact on infiltration. Overall, considering the small-scale range, we consider the effect of DIY street greening in regulating stormwater to be low to moderate.

We define community gardens here as self-organised transformations of public or semi-public spaces for growing vegetables, herbs, and ornamental plants, typically in raised beds and at a small, temporary scale. Community gardens are widely applied, but most often in the field of tactical urbanism or pop-up urbanism³⁴ and as authorised by gardening groups and city administration⁶³. Community gardens rarely emerge primarily as climate adaptation measures. Instead, they are more often motivated by goals such as social cohesion, placemaking, sustainable living, and access to healthy food^63,64,65. Tomatis et al.⁶⁶. reviewed potential climate adaptation benefits of allotment and community gardens, identifying contributions to microclimate regulation, extreme temperature mitigation, UHI reduction, and stormwater management through infiltration and retention. Most studies, however, focus on larger or planned gardens, such as allotments⁶⁷. In terms of OTC, moderate contributions are possible—especially when shade structures or small trees are included. Likewise, for UHI reduction, increased water availability through irrigation and higher vegetation density may offer greater benefits than other forms of street greening. In a simulation study⁶⁸, found small-scale planned gardens in Greece reduced air temperatures by 0.2–0.8 K.

Regarding stormwater regulation⁶⁹, observed that community gardens—especially those with raised beds and composting—outperform vacant or residential lots in runoff reduction. Similarly⁷⁰, found that gardens with compost amendments had higher evapotranspiration and lower leachate than turfgrass, enhancing their water retention and infiltration capacity. They concluded that compost-rich urban gardens may function similarly to engineered green infrastructure in managing stormwater.

Pop-up trees or movable tree boulevards consist of potted trees arranged to create temporary green alleys or boulevards. In some cases, also regularly tree planting was performed as DIY urbanism in the informal settlements of Dhaka, as analysed by. As an efficient adaptation measure for OTC enhancement and UHI reduction, tree planting is often prioritised where possible to provide shade and evaporative cooling for pedestrians^5,9. Tree shading can significantly reduce OTC indices, particularly by lowering Tmrt from 4 to 23 K according to recent reviews^2,5. In planned interventions, trees with larger crowns achieve greater cooling effects, with air temperature reductions ranging from approximately 0.9 to 2.8 K, as syntheses of the literature showed³. In their meta-analysis, Rahman et al.⁷¹ demonstrated that the microclimatic benefits of trees—shading, transpiration, and improvements in human thermal comfort—are strongly correlated with Leaf Area Index (LAI), which is the key characteristic enhancing these cooling mechanisms. In contrast, pop-up trees are typically limited by their smaller height, crown size, and leaf area density.

As noted above, vegetation—particularly trees—can reduce rainwater runoff through several mechanisms: interception of rainfall by the canopy, evaporation from leaf surfaces, enhanced infiltration around root zones, and water storage within tree trunks^18,59,60,61. During heavy rainfall, overflow of the interception is inevitable⁶⁰. The effectiveness of these processes increases with greater crown density, measured LAI, and more compact tree morphological traits¹⁸. Due to the potted trees mainly considered here, the ability to decrease surface run-off and to serve as a retentions spaces is clearly limited to the footprint as no additional water can be caught. Hence, a low to moderate effectiveness is estimated regarding stormwater management.

Parklets and parking days are among the most prominent interventions in DIY urbanism, involving the conversion of parking spaces into greened and furnished areas, often motivated by mobility transitions⁴⁰. Climate adaptation, however, is generally of limited importance in these approaches. The design of parklets varies widely, ranging from simple furniture installations to the inclusion of shading structures, vegetation, and small trees. Consequently, their effects on the urban environment can vary significantly. When combined with trees or sunshades, parklets may achieve moderate to high effectiveness in improving OTC. Parklets have been discussed in the context of sustainability, but more critically as green-washing, as their function in mitigating climate change is more symbolic⁴⁶. The inclusion of vegetation and trees can also contribute to a moderate reduction in UHI effects. In contrast, their impact on stormwater regulation is typically minor, unless located adjacent to urban gardening areas.

Rainwater harvesting is defined as the collection and reuse of rainwater using simple or homemade systems such as barrels, tanks, or landscaped catchment areas. Although rainwater harvesting is one of the oldest practices for water supply, its potential remains largely untapped in many regions, particularly across Europe and America¹⁶. Typically, rainwater is collected from rooftops or other impervious surfaces and directed into the storage system via gutters and downspouts. The stored water is then used to meet both indoor and outdoor building water demands¹⁶. Elder and Gerlak⁴⁵ analysed such systems as examples of DIY urbanism. However, due to the relatively small capacity of DIY rainwater harvesting setups, their impact on water retention tends to be moderate¹⁷. Besides reducing overall water consumption, rainwater harvesting offers additional benefits. When the harvested water is used for irrigating green spaces, it can increase evapotranspiration, which in turn may help reduce UHI effects¹⁷. As rainwater harvesting can reduce run-off also outside of its direct footprint, its effect is considered moderate to strong depending on its dimensions.

Curbside cuts and inlets can redirect stormwater from streets into green spaces or tree pits. As a DIY intervention, this can involve removing a section of the curb or cutting an inlet into the curbstone⁷². Curbside cuts have also been noted by⁴⁵ as a low-cost stormwater intervention. When properly designed—especially with depressed surfaces—these inlets can be cost-effective for stormwater management and improving water quality runoff^72,73. Their performance depends on factors such as inlet size, slope, drainage area, and street design. Depressed and longer inlets generally capture more runoff^72,73. The effectiveness also depends on where the water is directed. Inlets connected to blue-green infrastructure, such as street trees with engineered pits, can retain 5–90% of annual rainfall, depending on system size, soil properties, rainfall characteristics, and tree evapotranspiration, according to a recent review⁶². These systems also enhance tree health and cooling, though they may face risks such as salt exposure or waterlogging⁶². While engineered systems are most effective for retention, vegetation alone tends to contribute more to water quality improvement than to stormwater volume reduction⁶⁰. It is important to note that the cited studies are based on professionally planned and engineered systems. Therefore, the impact of DIY interventions—without proper soil drainage, substrate capacity, or surface depression—is expected to be significantly smaller.

Water sprinklers or misters can be implemented as low-tech and temporary cooling solutions—for example, using garden sprinklers or misting nozzles connected to fire hydrants or public taps. We have not found references about its usage as a DIY intervention in the literature. For improving OTC, sprinklers have proven to be highly effective. They can significantly reduce Tmrt by lowering long-wave radiation from heated surfaces, and also decrease UTCI and PET by up to 9-15 K as summarised in a review¹¹. The effectiveness of these measures strongly depends on surrounding meteorological conditions and the amount and distribution of water droplets¹¹ and are expected to be smaller for DIY sprinklers. In contrast, water features such as ponds or fountains have a limited impact on OTC as observed in a case-study⁷⁴. Their contribution to UHI reduction and air temperature reduction is generally minor and considered moderate⁷⁴. These measures, however, must be carefully evaluated in terms of freshwater availability and consumption. If non-potable or polluted water is used, potential health risks may arise.

Artificial shading includes parasols, sun sails, and other shading equipment in public spaces. During sunny conditions, reducing solar radiation is the most effective solution for lowering thermal discomfort. Shading can therefore be highly effective in reducing OTC stressors—particularly Tmrt and PET during daytime hours^3,75. The impact of shading on UHI reduction, though, is less clear. While shading can reduce air temperature during the day^13,75, it has also been found to increase surface temperatures at night due to reduced longwave radiative cooling⁷⁵. In addition, potential adverse effects on ventilation and airflow, which are crucial for cooling, must be considered⁷⁵. To avoid heat buildup under artificial shading, sun sails and canopies should be mounted high, not directly above pedestrians¹³. Compared to tree shade, artificial shading typically results in lower temperature reduction, since evapotranspirative cooling is absent¹³.

Street painting is defined as the use of paint on streets and public surfaces to reclaim, redesign, or signal alternative uses of urban space. In the context of this research, white and reflective coatings are relevant in order to increase albedo and thus reduce surface heating. So far, we have not found any case studies within DIY urbanism that have used street painting for this purpose. In planned adaptation, reflective coatings are particularly common on roof areas and are widely implemented and discussed as an adaptation measure¹². Reflective surfaces are highly effective in reducing UHI effects when applied at a larger scale, as reviewed by Lai et al.². When applied only to a small area of pavement, the reduction in air temperature was found to be just 0.3 K in the study by Black-Ingersoll et al.¹¹. For improving daytime OTC, reflective surfaces can produce trade-offs. Since higher amounts of reflected solar radiation can also increase thermal stress and PET, this may counteract some of the intended benefits, as summarised by Lai et al.². No effects are expected regarding stormwater retention.

The review of studies on the potential effectiveness of DIY interventions reveals that moderate to high effects can be achieved in the immediate surroundings for some interventions. It is important to note that the selected studies often involve engineered systems, which are likely to outperform DIY implementations. As such, the expected impacts of DIY urbanism interventions—which typically lack formal infrastructure, professional design, or long-term maintenance—should be interpreted as approximations. The effects are highly localised and often limited to the site of application. The example measures of DIY urbanism indicate that interventions typically green only a few square metres of public space. In San Francisco, almost 0.2 ha, of previously sealed surfaces have been greened by parklets to date⁴⁰. In contrast, the usual sizes of these interventions could be estimated to be a few square metres^27,34,45. While improvements in OTC, UHI reduction, and stormwater management can sometimes be achieved at the micro-γ scale, the impact on a broader neighbourhood or city level seems negligible, if the implementation takes place at just a few individual sites. Moreover, the respective climate zones have not been considered and the maximum reductions and effectiveness with an optimised design were considered. This preliminary assessment, does not replace experimental or modelling-based studies that should be conducted in the future.

Moreover, it is important to consider possible risks when implementing such an intervention. This consideration is crucial in the context of DIY urbanism, which, due to its project-oriented and often informal structure³⁷, may lack strategic coherence. To counter this, we suggest that DIY urbanism focus on no- or low-regret adaptation measures. Particularly, misting systems and reflective surfaces must be carefully designed to avoid trade-offs. By contrast, other measures, such as greening and shading, can often be considered “no-regret measures”, which can be implemented without risk of adverse climatic side effects. Moreover, it is important to note that green infrastructure, as a nature-based solution, can provide additional ecosystem services beyond the scope of this article, such as psychological benefits and stress reduction^6,7.