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How can site features affect development?

Updated: Jun 27, 2023

Are you wanting to subdivide or construct new dwellings on your site? Are you unsure of what you need to be considering in the first steps of planning your development?

In this blog series, we’ll be covering off some of the “must knows” in planning terms, before you get too far with your development plans. Last week we discussed zoning and overlays, and what that might mean for your development. You can find the blog here. This week, we will be looking at some common site constraints, and what you should look out for when planning your development.

Site constraints could include:

· Slope

· Stability

· Protected vegetation

· Watercourses or wetlands

· Floodplains

· Overland flowpaths

· Coastal erosion or inundation

· Soil contamination.

Site constraints can trigger the need for resource consent in Auckland under the Auckland Unitary Plan, and are often also issues the Council considers as part of subdivision consents or resource consent applications for new dwellings.

We take a look at some of the common site constraints below.

Slopes and Stability

Steep slopes may affect the location of access, driveways, building platforms or dwellings and can also affect servicing (which often relies on gravity). Topography can also mean retaining or earthworks are required, which is a cost consideration for the development overall.

If your property is relatively steep, a geotechnical engineer may need to provide a geotechnical assessment to confirm the location and extent of any land instability and ensure there are suitable areas for development. This assessment would usually suggest the best areas for development, and any remedial works or management required now, or when dwellings are built in the future or earthworks are undertaken.

You should also consider the areas for access, to ensure they’re suitable for vehicle maneuvering.


Your site may be affected by floodplains, and you can usually gain a high- level understanding of this from Council GIS maps. In Auckland for example, you can find general floodplain information here. However, this is based on high level modelling, so shouldn’t replace assessment by your engineer.

There are specific requirements in the Auckland Unitary Plan regarding development within a floodplain, including for earthworks, access, parking, when subdividing or constructing a new dwelling. The thresholds for when you need resource consent are often quite low.

In subdivisions, you must make sure building platforms are suitable for development and clear of floodplains (either in terms of location (preferably) or height) and that future vulnerability of dwellings has been assessed. This may result for example in a minimum finished floor level being required. This would usually be indicated in a consent notice condition on the new Records of Title.

If you’re constructing a new dwelling within a floodplain, similar requirements are present.

A flooding assessment would be required as part of your resource consent application. Your planner can usually recommend someone to provide this and manage these specialists inputs for you.

Protected vegetation

The Auckland Unitary Plan identifies notable trees or groups of trees as being some of the most significant trees in Auckland. The Unitary Plan aims to retain and protect these trees from development. Trees in the road reserve are also protected to ensure their continued contribution to attractive streets, pedestrian amenity and public health.

This protection also restricts the type of work you can undertake within the root zone of those trees, such as earthworks to create building platforms or vehicle access. In other cases, a street tree may need to be removed to enable a vehicle crossing to be constructed- this should be carefully considered as approval is often not granted. It’s best to consider other options in terms of locating vehicle crossings to avoid the need to remove any street trees.

You can find more information about works near trees in our blog here.

Other vegetation can also be protected, such as vegetation close to watercourses, wetlands or in the Significant Ecological Area (SEA) overlay. Your planner can provide advice on the resource consent triggers for your proposal.


Watercourses are common on rural sites, but there can also be watercourses in urban areas. Watercourses can impact on your development, including the location of building platforms, dwellings, earthworks, vegetation works and servicing. In addition, riparian yard setback requirements apply rather than the usual front, side and rear yard setbacks. Buildings should be located at least 20m from the edge of watercourses in rural zones and 10m in residential zones in Auckland, or resource consent is required.

Your Planner

Not all of these are relevant to every property or every type of development- your planner will help guide you on the investigations you need to understand the impact of site constraints, and usually manage the specialists reporting for your resource consent application.

Have more questions?

Do you want to find out more about how site constraints may affect your development? Contact us to discuss your site constraints and how to best take these into account in your development design.

We work with other specialists, including engineers, to manage the whole process for you from initial conception right through to the granting of resource consent.

You can contact us on or 427 9966. We look forward to helping you on your resource consent journey!

Mary Zhou is a Planner at Planning Plus®. Mary has been part of the Planning Plus team since 2021 and has a real passion and drive for all things planning. Mary has experience with a variety of projects including rural and urban land use, subdivision and feasibility analysis.


As with all our blogs this information is preliminary in nature only and we have used our best endeavours to ensure it is correct at the time of writing. It is not intended to substitute for your own investigations or obtaining specific advice on your proposal from professionals. Planning Plus LtdTM is not liable in any way for any errors or omissions. © Planning Plus Ltd 2023

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