How to Protect Trees During Building Work on Your Block

24 October 2026

Building work can be one of the most damaging events a mature tree will ever face. Excavation, heavy machinery, soil compaction, and changes to drainage can all cause decline that may not show up for months or even years. For property owners in Frankston, where many suburban blocks contain established native and exotic trees that contribute to local character, canopy cover, and habitat, understanding how to protect trees during construction is a practical priority. This guide explains the key steps to take before, during, and after building work to give your trees the best chance of survival.
Understand Your Obligations Before Work Begins
Before any construction starts, check whether trees on your property or neighbouring land are protected. Frankston City Council administers planning controls that can apply to certain trees, including those covered by a Vegetation Protection Overlay or Significant Landscape Overlay, as well as trees identified in local planning schemes. Some native vegetation may also be subject to state-level controls under Victoria's Planning and Environment Act framework. Contact Council's planning department early to confirm what applies to your site, because removing or damaging a protected tree without approval can result in https://treeremovalfrankston.com.au/about/ https://treeremovalfrankston.com.au/about/ penalties and delays to your project.

Your building permit and planning permit documentation may also require an arborist report, tree protection plan, or tree management plan. Engaging a qualified arborist at the design stage, rather than after construction has commenced, allows the house footprint, driveway, and services to be positioned to minimise impacts on root zones.
Assess the Tree Protection Zone
The Tree Protection Zone, often abbreviated as TPZ, is the area around a tree's trunk that needs to remain undisturbed to protect its root system. As a general guide used in Australian arboricultural practice, the TPZ is calculated from the trunk diameter measured at 1.4 metres above ground, multiplied by a factor, often around 12 times for many species. The Structural Root Zone, or SRZ, is a smaller area closer to the trunk that is critical for stability and should not be disturbed at all.

Your arborist should map these zones on a site plan so that builders, excavators, and delivery drivers know exactly where restricted areas lie. Pegging out the zones and marking them clearly on the ground is one of the most effective ways to prevent accidental encroachment.
Install Physical Protection Before Construction
Once the TPZ is identified, install a fence to keep machinery, materials, and foot traffic out of the area. Temporary fencing panels mounted on stands are commonly used on residential sites and should be at least 1.8 metres high where possible. Place mulch of around 100 millimetres depth within the protected area if soil is exposed, and use signage stating that the zone is a no-go area. Trunk protection with timber battens or wrapping may be recommended for trees near access routes.
Keep stockpiles of soil, sand, rubble, and building materials outside the TPZ. Avoid refuelling, washing equipment, or disposing of concrete washout within the protected area. Do not attach signage, cables, or lighting to tree trunks. Prevent vehicles from parking or turning over root zones. Manage Excavation and Root Damage
Excavation is the most common cause of serious root damage. Where trenching for services or footings must encroach on the TPZ, the arborist may recommend hand digging, air spading, or tunnelling beneath roots rather than mechanical excavation. Roots larger than around 50 millimetres in diameter should generally be retained where possible, and any necessary root pruning should be carried out cleanly with sharp tools by a qualified professional. Ripping or tearing roots leaves wounds vulnerable to decay.

Foundations may need to be redesigned, for example using pier and beam construction, to bridge over roots rather than cutting through them. Discuss these options with your building designer and structural engineer early in the process.
Protect Soil Health and Drainage
Soil compaction from heavy machinery reduces oxygen and water movement to roots, and it can persist for years. Use ground protection such as rumble boards, steel plates, or a layer of crushed rock over geotextile fabric in areas where vehicles must travel near trees. Avoid altering existing ground levels within the TPZ, as adding even a small amount of fill can suffocate roots, and cutting soil away can remove essential feeder roots.

Changes to stormwater runoff from new roofs and paved areas can also affect tree health. Direct drainage away from root zones where practical, and avoid creating permanently waterlogged conditions.
Monitor and Care for Trees After Building Work
Tree decline after construction is often delayed, so monitoring should continue for at least 12 to 24 months after works finish. Watch for dieback in the canopy, reduced leaf size, early autumn colour, sparse foliage, fungal growth at the base, or leaning. Arrange a follow-up inspection with an arborist to assess condition and recommend corrective actions such as deep watering, mulching, nutrient management, or pruning to remove damaged branches.

Protecting trees during building work requires planning, professional input, and consistent site management. By identifying protected trees, respecting root zones, and maintaining soil and drainage conditions, Frankston property owners can preserve valuable trees that enhance their homes and support the wider urban canopy for years to come.

Frankston Tree Removal Experts

5/42 Hartnett Dr, Seaford VIC 3198

(03) 8820 1799