In this article written for NZ Property Investor magazine, Fraser Thomas Director Mason Reed explains why you should engage qualified professionals prior to commencing your development.
Given that we will all shortly be emerging from the government imposed state of hibernation, I thought it would be an opportune time to remind the readers of some of the potential pitfalls in development projects (from an engineering and land surveying perspective).
The take-away from the following, is that when you are considering any infill development or the purchase of a property for intended development it is critical that you engage appropriately qualified and experienced professionals (surveyors and engineers) to ensure your development will be a success.
Only following completion of a full feasibility of a particular site, by a professional with the necessary experience in infill housing and land development, will the development potential of the site be reliably known.
Your land development professional will work with your nominated Housing Company or Architectural Designer to assess what can be accommodated on the site. The planning controls of the District or Unitary Plan will largely dictate the design controls.
These details are usually required by any lending agency that you may be working with to fund the project.
Many of the Local Authorities District and Unitary Plans have relaxed their controls, to allow higher intensity development to occur within our urban centres. So now is the time to be looking at realizing the value in your existing property or purchasing to develop.
There are geotechnical hazards which are normally associated with coastal land, which purchasers need to be aware of. Steep coastal cliff sites, which are popular sites for expensive houses, are also subjected to an additional force, that being coastal erosion by wave action.
Properties located on coastal cliff lines are subject to a greater risk of slope instability than properties located elsewhere, due to the risk of cliff line regression occurring. The increased risk to any building can however be mitigated by appropriate foundation design, taking into account the various factors affecting cliff line regression.
My advice to anyone considering purchasing coastal land, is to engage a suitably qualified and experienced geotechnical engineer to undertake a pre-purchase assessment, in order to determine the risk of the land being adversely affected by cliffline regression. Buyers should be aware that coastal properties are subject to a greater risk of slope instability than properties located elsewhere.
Excavations Close to Boundaries
Sloping sites can create challenges when undertaking building development works. Typically, earthworks are undertaken on sloping sites to create level building platforms and/or suitable accessways or carpark areas. 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.
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. Building works, which includes the construction of retaining walls, are subject to the requirements of the Building Act 2004.
It you are undertaking building development works which involves excavations close to boundaries, my advice to you is to engage appropriately qualified and experienced professional engineers to provide earthworks design recommendations and to design any proposed permanent retention structures. It is recommended that advice also be sought as to an appropriate construction methodology and the stability of temporary (during construction) excavation slopes.
We always advise our clients, for these types of works, to also undertake a condition survey of any neighbouring sites, prior to undertaking any excavation works, so as to provide proof as to the condition of neighbouring land and buildings (prior to you undertaking any works.
Identifying Property Boundaries
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, severely damaged or previously removed by building works. If the boundary pegs are not obvious, it may be prudent to have them located or replaced before any design, development or building development works commences.
The consequences of not correctly identifying the property boundaries, when undertaking building developments, can be significant, and costly to rectify.
On a flat, newly developed subdivision, the average builder can generally set out the proposed building location, using the boundary pegs and a locally defined height datum point. However, the set out becomes increasingly difficult for a builder when the pegs are missing, the property and/or building are not the usual rectangular shapes, or the land is steeply sloping.
To mitigate the risk of your next building development not being built in the correct place, and worse still, being built on the neighbour’s property, you should always engage the services of a Licensed Cadastral Surveyor, particularly when the building works are located in close proximity to site boundaries.