Climate proofing of building codes

Description

The building sector is challenged by a number of climate change impacts, including increase in temperature, higher frequency and magnitude of extreme weather events and sea level rise. Rising temperatures and extended heatwave periods can increase urban heat islands, internal and external thermal discomforts and the demand for energy for cooling systems of buildings. Weather extremes generating floods or landslides can lead to both short-term and long-term service interruptions to buildings (e.g. energy, gas, water, optical fibre, etc.). On the other hand, buildings are one of the main energy demanding sectors, significantly contributing to climate change. In order to achieve the EU goal of climate neutrality by 2050, the building sector will have to drastically reduce its energy demand and will need to respond to the climate change impact with already available adaptation options. 

Measures for climate proofing urban planning and design can be taken at different spatial scales, in particular at the levels of urban spaces and buildings. Urban spaces should be re-qualified and designed with specific technical options to respond to climate change impacts, such as urban flooding and heat islands. Buildings should be designed to reduce the energy demand and to be better adapted to climate impacts, both with respect to heat and cold and with respect to flood resilience. Many climate-related aspects can be faced through the updating/drafting of building codes, in terms of optimization of construction energy, material production energy and building energy demands. As the form and structure of buildings and urban morphologies are strongly determined by building codes, these instruments need to be revised and adapted to climate-related needs, and if such codes have not yet been established, new ones should be developed and approved specifically aiming to make the building sector more resilient and climate proof. Recycling practices and low energy consumption of building activities and materials production are relevant fields for the innovation of the building codes. 

Climate proofing of building codes is an adaptation option in the hands of local authorities, which involves various aspects of the building sector related to construction, manufacturing, maintenance and provision of services. Beyond improving the adaptation to climate change and contributing to the mitigation, climate proofing of building codes also has the potential of contributing to the improvement of the quality of urban spaces and of the life of their inhabitants. In exemplary cases the implementation of building codes is carried out by administrative technicians, practitioners and researchers, and the dissemination of the updates through citizens involvement (direct or through the information channels). 

Adaptation of the urban space and buildings aims at maintaining and protecting them from damages caused by climate extremes and changes. Adaptation measures include the revision and improvement of long-established practices, but also introducing new practices and technological innovations (for example new materials or systems), among those also green measures for both urban spaces and buildings. These adaptation options can be integrated within the existing or new building codes, using them for promoting efficiently a wide variety of specific measures, such as:

• Low-tech adaptation measures traditionally used in Mediterranean cities and towns, e.g. proper exposure of building surfaces to maximise dispersion and minimize solar radiation, proper orientation of buildings to limit solar radiation and benefit from wind circulation, use of architectonic elements for shadowing, use of thick external walls.
• Hi-tech solutions, such as sensors to monitor thermal conditions and to optimize air conditioning and ventilation, sensors for the optimal orientation of shading panels or hi-tech materials (with high thermal resistance) to optimize heat dispersion reducing thickness/dimensions of elements.
• Trees and plants in the external areas of the building to provide shadow, increase air flow and reduce the impact of solar radiation and the heat-island effect.
• White and green roofs to reduce the heat-island effect by naturally keeping building surfaces cool through reflection of solar radiation and evaporative cooling by water and vegetation. 
• Measures specifically aimed at preventing urban run-off and flooding which can be implemented at the building scale, in particular those increasing surface permeability and capacity for rainwater storage.
• Properly dimensioned systems for rainwater collection and reuse, e.g. for irrigation, urban farming or toilet flushing.

According to the Italian National Adaptation Strategy, the effects of climate change on the building sector have not yet been fully mapped and assessed. The strategy recommends the consideration of climate change mitigation and adaptation within the current urban planning tools and building codes. In Italy some progressive municipalities have adopted the R.I.E. (Reduction of the Building Impact) within their building regulations, as in the case of Bolzano, Bologna and Reggio Emilia. The R.I.E. is a numerical index which evaluates the effect of a building intervention in terms of permeability compared to natural soil and green areas. Soil sealing caused by building structures can partly be compensated through new vegetated surfaces such as green roofs, engineering-biological technologies or greening and planting interventions providing options for water infiltration into the soil and retention of rainwater. In Bolzano, for example, there is a minimum coefficient to be reached according to different building zones (commercial, residential, etc.) for interventions on the existing and new buildings, as well as on outdoor surfaces which are exposed to precipitation (roofing, terraces, outdoor structures, courtyards, green spaces, areas with flooring, parking lots, etc.).The Coastal Flood Resilience Design Guidelines for the city of Boston are an example of how the revision of building codes can enable action by homeowners. Recently developed for the city of Boston, they are a resource to inform property owners and developers about flood protection measures and systems for the existing buildings and new constructions (http://www.bostonplans.org/getattachment/d1114318-1b95-487c-bc36-682f8594e8b2). Moreover, the Boston example shows that eventually resilience improvements could contribute to raising property values, and so reduce affordability for residents, especially for renters and students, therefore, measures enhancing social equity and protecting socially vulnerable populations are needed.

Costs and benefits

Depending on the existing administrative procedures, costs of revisions of building codes are initially low. The actual cost is represented by the time and the technical skills needed for the revision of the existing regulations or the development of new building codes, and the subsequent approval, while the costs of the specific adaptation measures promoted through climate proofed building codes are variable and have to be borne by the owners of the buildings. The highest costs refer to complex interventions of renovation of the existing infrastructures. Lower costs refer to those interventions that can be applied at the small scale of a building or of a specific urban infrastructure.

Climate-proofed building codes can foresee compensatory packages or incentive packages to introduce innovative measures. Tax relief mechanisms (tax incentives) can be introduced to facilitate the structural integration of such new measures into the common building practice. 

Benefits include the overall reduction of the vulnerability of the building systems, reducing malfunctions and inefficiencies due to the climate change and damages caused by extreme climate events, reduced energy costs and, for instance in the case of measures related to flood protection, in the reduction of losses due to flooding and inundation. This adaptation option brings also important co-benefits in terms of the reduction of emissions owing to reduced energy consumption, can increase liveability of urban spaces and citizens’ health. For example, the new building of the energy department of the Madrid Institute for Advanced Studies (IMDEA) incorporates different climate change adaptation solutions (https://climate-adapt.eea.europa.eu/metadata/case-studies/white-roof-innovative-solar-shadings-and-bioclimatic-design-in-madrid).

Implementation time and lifetime

Changing urban and building codes is a long process and the time needed for the implementation of large-scale measures is typically in the range of several years (approximately 5-15 years). Specifically, the technical part of the revision of an existing code, or the draft of a new one, can take approximately 3 years. The estimated time for the whole process considers the whole path from the initial need for update to the implementation and the assessments of measures and actions. Such a long time can act as a barrier for this kind of interventions. Working on climate proofing of building codes means working on results which are expected to be visible and accessible in decades. However, this prevention approach can reduce damages and recover the initial costs. Moreover, many of the small-scale, low-tech measures can be easily and quickly implemented. The measures implementation is independent from the existence of a code, but once activated, the regulation might trigger the implementation among private homeowners.

As an intermediate, yet less effective, measure, guidelines for owners and investors proposing measures for climate proofing of buildings can be issued providing knowledge and recommendations on climate risks and effective measures for their mitigation without relying on regulations and compulsory measures, as for example those published by the City of Boston. (http://www.bostonplans.org/getattachment/d1114318-1b95-487c-bc36-682f8594e8b2).

Updating of building codes based on new climate knowledge and on the evaluation of experiences with a first version of the R.I.E. measure is also an important aspect. The city of Bolzano, which has had this measure in place for 15 years, is assessing the impacts and criticalities of the implementation (https://www.buongiornosuedtirol.it/2020/02/bolzano-aggiornamento-indice-rie-riduzione-dellimpatto-edilizio/).

Source for more detailed information

Comune di Bolzano – Deliberazione del Consiglio Comunale n. 11 del 10.02.2004 – Procedura R.I.E. http://www.comune.bolzano.it/urb_context02.jsp%3FID_LINK%3D512%26page%3D10%26area%3D74%26id_context%3D4663

Comune di Bolzano – Allegato A del Regolamento Edilizio – Procedura R.I.E (Riduzione dell’Impatto Edilizio) https://www.comune.bolzano.it/context05.jsp?ID_LINK=1377&area=19&id_context=7029&page=27

Comune di Padova, (2016) Padova Resiliente: Linee Guida per la costruzione del Piano di Adattamento al cambiamento climatico, Padova

Faivre N., Fritz M., Freitas T., de Boissezon B., Vandewoestijne S., Nature- Based Solutions in the EU: Innovating with nature to address social, economic and environmental challenges

Foster J., Lowe A., Winkelman S., (2011), The value of green infrastructure for urban climate adaptation, The Center for Clean Air Policy