Safety of our homes

A growing concern is the lack of professional attention given to safety and integrity of new homes frequently observed at construction sites. Ground failure, rarely heard of in the past, seems to become annoyingly too frequent for one's liking.

As built-up areas continue to grow, this man-made phenomenon is expected to proliferate. Settlement occurs under all foundations in all soil conditions. While lightly loaded structures or rock sites may experience negligible settlement, heavier structures on softer sites, both overall settlement relative to undeveloped voids or neighbouring buildings, and differential settlement under a single structure, can cause problems.

This is settlement which occurs over time, as immediate settlement can usually be compensated for during construction. Ground movement beneath a structure's foundations can occur due to shrinkage or swelling due to climatic changes, slope instability, or other causes.

All these factors must be considered during the design of the foundations. Ground, or to be more precise, foundation failure, is often the result of a lack of precautionary measures which should have be taken before commissioning the initial stages of construction. Within newly built areas this aspect is frequently overlooked or disregarded.

A properly planned construction project begins with a site investigation of the bedrock in the area of interest to determine its geo-engineering properties and how it interacts once the proposed structure is in place. Site investigations are needed since it is the only means of gaining full understanding of the area in or on which the works will eventually take place.

Through these investigations one should be able to make a full assessment of potential risks to humans, property and the environment from likely hazards such as landslides, sinkholes, soil liquefaction, debris flows and rock falls. We have experienced several serious cases of immediate or gradual ground failure in this regard, most spectacularly manifested as mudslides triggered by excavations.

The unpredictability of the ground is a potential liability to the unprotected third party particularly with redeveloped sites that are excavated perpendicularly down flash against existing third party walls, sometimes a number of stories deep. Ironically, as it stands, MEPA is not legally responsible for the safety of the ground and construction methodology, despite that any development requires a permit.

Many are those who at one time or another fell victim of such occurrences, and others in the construction industry feel it is high time local authorities intervene by introducing legislation making it obligatory to hold a detailed geo-technical survey of land about to be developed.

This will ensure that the limiting factors of the terrain are well understood and safety factors such as, for instance, distances between buildings, load bearing capacity and limits on excavated depths are established.  

A new Labour government will address the issue as indicated in the approved Environment policy document by taking the necessary legislative steps and in addition shall substantiate its effort by setting up of a Geo-technical unit to provide such service.

Mr Galdes is the Labour Party's spokesman on the environment and natural heritage.