Having a clear understanding of the accurate location of your property boundary is critically important when undertaking building developments, in particular when the works are to be located close to your neighbour’s property.

The reason for this is that property boundaries are not always obvious. While a fence, hedge or driveway may look as though it defines the edge of a property, the actual boundary locations can be quite different. In many areas the boundary pegs may be missing, eroded by time or previously removed by building works.

The consequences of not correctly identifying the property boundaries when undertaking building developments can be significant and costly to rectify. I am aware of projects where the architect assumed that the fence at the property was on the boundary and subsequently designed a new dwelling (to maximise the space), which resulted in the dwelling being located as close as council would allow to the neighbour’s property boundary. It was discovered, when the surveyor was engaged to set out the building location, that the existing fence was not in fact on the boundary.

As a consequence, the proposed new building (if built) would have encroached into the neighbour’s property. If this error had not been picked up by the surveyor, and the house had been built into the neighbour’s property, then it is likely that the house would have had to be demolished (at great expense).

‘If you inadvertently excavate into the neighbour’s property, you will clearly be liable for the reinstatement of the exacavated land and for the remediation of any damage, to the neighbour’s satisfaction’

Your Responsibility

Another situation when it is critically important to have a clear understanding as to the location of site boundaries, would be if you were undertaking excavation works close to your site boundary, in order to form a level building platform.

These earthworks can result in permanent batter slopes, which need to be designed/constructed to a safe batter angle, so as to prevent erosion or instability of the batter slopes.

On smaller sites, which are physically constrained and where it is not possible to fit in safe batter slope profiles, the batter slopes are generally permanently retained by retaining walls. Typically retaining walls, particularly on or close to the boundaries of neighbouring sites, need to be carefully designed and constructed, so as not to cause damage to the neighbour’s land (or buildings on that land). If the location of the site boundary is not reliably known, there is a risk that the excavation works - or the retaining wall itself - could encroach into the neighbour’s property.

If you are undertaking building works on your property, you are legally required to ensure that the works do not result in damage to land or buildings on neighbouring properties. If you inadvertently excavate into the neighbour’s property, you will clearly be liable for the reinstatement of the excavated land and for the remediation of any damage, to the neighbour’s satisfaction. These costs are amplified if the loss of ground support affects foundations supporting neighbouring buildings. Clearly, if you construct a retaining wall on the neighbour’s property you are effectively stealing some of the neighbour’s land, and you will likely need to demolish/remove the wall and to re-construct the wall on your side of the boundary.

So, if you are undertaking building work close to the site boundary, do not assume that the rickety old fence (which has been there for many years) is located on the property boundary, because it may not be, and the consequences of getting this wrong could be very expensive.

My advice is to get a Licensed Cadastral Surveyor involved, in the early design stages, to determine the location of the property boundaries. Licensed Cadastral Surveyors are the only persons permitted to place survey pegs, which determine the property boundaries. Fraser Thomas Ltd has a number of Licensed Cadastral Surveyors, all of whom are experienced in undertaking this type of work.