Careful now: three signs reveal a building that is risky right down to the foundations: “Buildings should be considered from a 50 or 100-year perspective”

The housing market has showed some faint positive signs this spring. If you are looking to buy a home for life, you should also consider the building’s weather-resilience.

Climate change has increased the frequency of extreme weather events, with no end in sight. Buildings will be put under greater strain due to factors such as heavy rainfall, diagonal rain, flooding and extreme temperature fluctuations.

Anna Keskinen, City of Helsinki building physics specialist and team manager, lists three easy tips that anyone can use to assess whether a building meets the criteria required by current conditions.

1. Plinth too shallow

The foundation of a residential building, the plinth, should be at least 30 centimetres high. Although this guideline is unambiguous, Keskinen says it is not even followed in all new buildings – on the contrary, even windows can be right at ground level.

Climate change will lead to increased flooding and stormwater run-off. The need for maintenance is particularly prominent for shallow plinths. If left unmaintained, a plinth that is too shallow will significantly increase the risk of water damage. 

According to Keskinen, climate change is progressing all the time and should also be taken into account in construction. The current conditions are not permanent and will change.

“Buildings should be considered from a perspective of 50 or 100 years.

An easy way to check the height of the plinth is to put a man’s shoe against the plinth. In men’s shoes, the distance between the toe and the heel is usually about 30 centimetres,” Keskinen says.

2. Vegetation growing close to the foundation

Flowerbeds are beautiful, but if they are planted right next to the building’s foundation, they can spell doom for the whole building. Planted vegetation should be placed far enough away from the foundations to prevent moisture from being trapped in the structures.

Virginia creepers crawling up the walls of buildings are often loved by people, but they can be a nuisance.

“The vines penetrate every hole and cavity and keep structures damp, which can encourage mould growth in the long term and when weather turns warmer.”

Keskinen points out that abundant vegetation is still good in principle, as long as it is planted right. In the event of heavy rainfall, for example, a lush yard absorbs water well, preventing flooding better than a paved or asphalted yard.

3. Straight window sills

It’s simple: window sills should tilt away from the windows. If the window sills are straight, water is more likely to penetrate between the window panes and, in the worst case scenario, all the way inside.

“This can lead to all kinds of trouble, including from a liability point of view,” Keskinen states.

Typically, outer window frames and panes are the responsibility of the housing company. The shareholder’s maintenance responsibility includes the inner and middle window frames, as well as the inner panes and the ventilation hatch.

“A housing company can try to claim that you have not kept the windows in good condition, even if the leak is due to the external structures,” Keskinen says.

Keskinen adds that waterproofing windows is even more important now, as climate change has increased the amount of diagonal rain, especially in coastal areas. Diagonal rain occurs when the wind causes water to rain perpendicularly, making it easier for it to penetrate structures.

Last winter was a nightmare for buildings

Keskinen describes the past winter as a nightmare for buildings. Temperatures have been constantly hovering between minus and plus degrees, with alternating rain and snow fall, and buildings could not really dry properly due to the humid weather.

Constant humidity is not good for buildings, as it contributes to the growth of microbes in structures.

Keskinen proposes that housing companies should, in general, be more prepared for climate change, and property managers should be given more training on the matter, for example. Finland’s climate is becoming more Central European in nature, and we should realise this ahead of time. 

Preparing for climate change should be taken into account when planning façade renovations, for example. The City of Helsinki’s Building Control Services offer free and impartial advice on the subject, for example. Read more here: Sustainable housing company

Text: Matti Tuomela, Mellakka