Some 170,000 properties in the northern province of Groningen need to be shored up to prevent further earthquake damage, according to research carried out on behalf of the provincial council.

The total involves 152,000 private homes and 18,000 other buildings and it will take 27 years before the work is completed, the research states.

‘This is in line with expectations because when these properties were built, the risk of earthquakes was not taken into account,’ the province says.

The researchers looked at several different types of property common in the province to assess the risk of damage: two different detached homes, two types of semi-detached homes, terraced property and an apartment complex.

Follow-up research is now needed to establish exactly what action needs to be taken, the province says.

Meanwhile, the Financieele Dagblad reports that oil and gas firm NAM – a joint venture between Shell and Exxon Mobil – has bought up 13 properties in the province since September 2013.

Six of the properties were bought because they had become uninhabitable. The others are being used for research, the FD says.