The climate in Norway is cold for most of the year, which has historically influenced building construction and urban development to focus on retaining heat.

However, with global temperatures on the rise and heat waves becoming more frequent and intense, this design is now posing challenges.

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The emphasis on heat retention in Norwegian buildings means that heat can quickly become overwhelming when temperatures soar to 25C or higher.

But which factors affect heat retention, and what can residents do to mitigate the effects of the country’s increasingly common heat waves?

Why Norwegian homes traditionally focus on getting light and heat in

In Norway, there are relatively few months when it gets uncomfortably hot indoors, but when it does happen, it can be pretty unpleasant.

Several factors influence indoor temperature, including the level of insulation and the size and location of windows.

Despite Norwegian houses being well-insulated and transferring minimal heat through walls, windows are often significant culprits in heat transfer.

To prevent excessive indoor heat, it’s essential to block it from entering in the first place. Historically, Norwegian homes have prioritised getting light and warmth in, leading to larger windows without much shading.

As a result, managing heat indoors requires strategies such as screening windows or external sun shading to reduce sunlight penetration.

Furthermore, maintaining a cool indoor environment by keeping heat out can be achieved by using heavy materials like concrete in building construction, which helps retain cooler temperatures when windows and vents are properly shielded and closed.

A 2023 report from Oxford University placed Norway among the countries which are the most poorly prepared for increasing global temperatures.

Heatwaves in Norway becoming more frequent

Heat waves are defined differently across different countries, and there isn’t a single universal definition.

The Norwegian Meteorological Institute defines a heat wave as a period during which temperatures exceed 28C during the day and do not fall below 16C at night for five consecutive days.

In recent decades, heat waves have become more common in Norway. The frequency of these extreme weather events has significantly increased over the last thirty years.

For instance, regions in Viken are now experiencing twice as many heatwaves as they did thirty years ago, according to recent reports from the Norwegian Broadcasting Corporation (NRK).

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A 2019 report from the Meteorological Institute highlighted the growing prevalence and intensity of heatwaves in the country, noting that most heatwaves occur in the valleys of eastern Norway, where still air can lead to very high temperatures.

Areas far from the sea also lack the cooling effect of coastal breezes, exacerbating the heat.

Furthermore, the institute has observed that heatwaves are expanding to more inland areas and regions like western Norway and Trøndelag, which traditionally experienced fewer such events.

Urban design and its impact on heat

These prolonged periods of high temperatures are posing particular challenges for city inhabitants in Norway.

The way Norwegian big cities – such as Oslo and Bergen – are designed often exacerbates heat waves, as buildings and asphalt surfaces absorb and store heat from the sun.

This phenomenon, known as the urban heat island effect, makes cities susceptible to higher temperatures.

Engineering consultancy company Sweco recently published a report showcasing the findings of its investigation into how various European cities, including Oslo, can build resilience against heat waves.

Oslo’s unique topography, with its basin shape and compact city centre, heightens the risk of the urban heat island effect, the consultancy warned.

Over the past century, Oslo’s climate has warmed by 1.5C.

Despite being considered less exposed to climate risks globally, Norway’s capital experienced consistently high temperatures and drought from 2016 to 2018, increasing the risk of wildfires in the surrounding forests.

Guro Sørnes Kjerschow, a special advisor for climate change adaptation in Oslo, told Sweco that increasing temperatures bring challenges to public health and nature.

Therefore, Oslo Municipality is developing solutions to manage higher temperatures, especially for vulnerable populations, by enhancing green spaces, planting trees, and reopening streams in an attempt to mitigate the effects of warmer weather.

These efforts are crucial as buildings and city areas, originally designed to tackle long, cold winters, are now ill-equipped to handle rising temperatures.