Surface Development Guideline 2

Guideline 2 applies to properties with a risk of trough subsidence. Trough subsidence forms as a result of the presence of underlying, unstable historical coal mine workings.

Allowable residential construction

Development that complies with this Guideline will generally accommodate the following subsidence-induced ground movements: 

Guideline 2 allows for up to two residential buildings that conform with the following description:

Single or two storey brick veneer residential developments erected on reinforced concrete footings/slab to comply with AS 2870-2011. These improvements are limited to a maximum length of 24 metres and maximum footprint size of 400m².

• The 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 Site is to be ignored for these structures.
• Masonry is to be articulated, in accordance with the current editions of Australian Standards AS3700 and AS4773.
• Both slab on ground and lightweight bearers and joists are permitted. 

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 residential 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 2:

• Concrete swimming pools, both in-ground and above-ground
• Retaining walls (not supporting structures) 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 NSW Coal Mine Subsidence Compensation Act 2017.

For a full list of exempt developments, please refer to Subsidence Advisory’s Exempt Development list.

Proposed developments that do not comply with Guideline 2

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 2

Applications for proposed developments that comply 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.