Underpinning in Marrickville
Inner West Council's development application guide asks for a structural engineer's report where a proposal involves excavation under or in close proximity to an existing building that is to be retained. Marrickville is in that Council's area, and whether a given repair to a footing needs an application at all is not something the guide says.
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Underpinning around Marrickville
We sampled the state's soil-landscape mapping at five points across Marrickville. Three returned the Blacktown unit, gently undulating rises on Wianamatta shales whose limitations include moderately reactive, highly plastic subsoil, and two returned the Birrong unit, level alluvial ground whose limitations include seasonal waterlogging and saline subsoil. Those are two different footing questions in one suburb, and neither report speaks for a particular house.
The state's planning layer maps Inner West acid sulfate classes at four of our five points: Class 5 at two, Class 4 at one and Class 2 at one. The Inner West plan also lists seven heritage conservation areas under Marrickville's name. Development consent is required to alter the exterior of a building in one, and the NSW Codes SEPP's exempt restumping and foundation repair does not apply there.
Permits and Inner West Council rules
Inner West Council's DA Lodgement Guide says a report from a suitably qualified structural engineer is required where substantial demolition of an existing building is proposed, or excavation under or in close proximity to an existing building that is proposed to be retained. A geotechnical report, prepared and certified by a geotechnical engineer, is required to excavate 2 m or more below existing ground level, and the issues to be addressed include dilapidation reporting and excavation support. Those are documents for a development application; whether a repair to an existing footing needs one is not something the guide says. Where a consent involves excavation below a neighbour's footings, the state's Regulation puts the cost of protecting the neighbouring building on the consent holder.
Source: Inner West Council, DA Lodgement Guide for Applicants (May 2026); Inner West Local Environmental Plan 2022 (current version for 4 September 2026); Environmental Planning and Assessment Regulation 2021 s 74; read 21 September 2026. — confirm current requirements with Inner West Council.
Our Marrickville service area
An enquiry from Marrickville is referred on to an independent provider, who gets in touch to look at the house.
See all Underpinning in Sydney. We also work in Mascot, where Bayside Council maps acid sulfate soils over filled ground.
Call (02) 9072 0403Last reviewed · Updated · First published