Surface Development Guideline 3A
This page explains the requirements for constructing a complying development on a property in a Mine Subsidence District that has been assigned Guideline 3A.
Guideline 3A applies to properties with either a remote risk of subsidence, or at a very low residual subsidence risk. Guideline 3A will apply to areas above previous longwall mining operations and where pillars have been fully extracted.
Development that complies with this Guideline will generally accommodate the following subsidence-induced ground movements:
Maximum Horizontal Ground Strain | 1 mm/m tensile or compressive |
Maximum Tilt | 1 mm/m |
Minimum Radius of Curvature | 12 km (hogging and sagging). |
Allowable residential construction
Guideline 3A allows for up to two complying developments that conform with the following description:
- Up to two storey brick veneer developments or up to three storey lightweight clad frame developments erected on reinforced concrete footings/slab to comply with AS 2870-2011. These improvements are limited to a maximum length of 36 metres and maximum footprint size of 600m².
- These buildings are to be designed and constructed in accordance with the current editions of AS1684, AS 2870, AS3600, AS3700, AS4773, the National Construction Code, and applicable Australian Standards. Site classification “P” for Mine Subsidence is to be ignored for these structures.
Masonry is to be articulated, in accordance with the current editions of Australian Standards AS3700 and AS4773.
Prohibited works
The following works are not permitted under this Guideline:
- Integral retaining walls supporting the structure of the building
- Basements (including partial basements where one or more walls acts as a retaining wall)
- Suspended, drop edge or stepped slabs
- Masonry internal walls
Commercial buildings or applications for more than two separate buildings require assessment by Subsidence Advisory in accordance with its Merit Assessment Policy.
Other allowable additions and improvements
The below types of additions and improvements are also permitted on properties subject to Guideline 3A:
- Concrete swimming pools, both in-ground and above-ground
- Retaining walls designed and constructed in accordance with relevant applicable Australian Standards.
Exempt developments
In addition to the above, Subsidence Advisory has exempted some minor construction works from requiring approval under s22 of the Act.
For a full list of exempt developments, please refer to Subsidence Advisory’s Exempt Development list.
Proposed developments that do not comply with Guideline 3A
Applications for proposed improvements that do not comply with the Guideline assigned to the property may be assessed under Subsidence Advisory’s Merit Assessment Policy.
Who can assess whether development complies with Guideline 3A
Applications for proposed development that complies with this Guideline can be assessed by Subsidence Advisory, the relevant council or a registered certifier as defined in the Environmental Planning and Assessment Act 1979.
Disclaimer
Please note that Subsidence Advisory’s Surface Development Guidelines are subject to change.