Concrete Underpinning SA 2026 - Costs, Methods, When It Is Needed, and What Drives Foundation Movement in Adelaide

Concrete Underpinning in South Australia

Underpinning is the structural process of strengthening or extending the foundations of an existing building to restore stability, arrest movement, or enable the addition of building loads above. In South Australia, the vast majority of residential underpinning work is driven by reactive clay soil movement that the original building's footings were not designed to accommodate, either because the footings were inadequately specified for the soil class at the time of construction, or because the moisture conditions in the soil around the building have changed since construction in ways that have increased the magnitude of reactive soil movement beyond what the original design could tolerate. The reactive clay conditions that drive most SA underpinning demand also affect concrete slabs, concrete driveways, and all outdoor concrete on Adelaide clay sites.

The SA underpinning market is a significant and growing sector of the residential construction services industry. Homes built in Adelaide's northern and southern suburbs during the 1960s, 1970s, and 1980s were frequently constructed to footing standards that did not adequately address the H1 and H2 reactive clay soils of those areas. As these homes age, the cumulative effects of seasonal soil movement, vegetation changes (trees and gardens established since construction that have altered the moisture regime around the building), and in some cases changes to drainage from nearby development all compound into foundation movement that was not present in the building's early years. Homeowners who notice progressive cracking in their walls, sticking doors and windows, and uneven floors are observing the visible signs of the foundation movement that underpinning addresses. For SA patios affected by foundation movement, our concrete patios SA guide covers the specification a replacement patio should include to prevent similar movement. Engaging a building consultant for an independent assessment before commissioning underpinning is the correct first step when cracking origin is uncertain.

It is critical to understand that underpinning is not always the correct response to foundation movement on an SA property. In many Adelaide cases, the movement is driven by a specific and correctable moisture source, and correcting that source is sufficient to arrest the movement without any structural intervention. Underpinning a foundation while the moisture source that is driving the movement remains active is like repairing a leaking roof while the rain continues: the repair may slow the consequences, but the underlying problem continues. The correct sequence in SA is always diagnosis first, then treatment of the cause, then monitoring to confirm the treatment was effective, then structural underpinning only if the residual movement after treatment remains unacceptable. For SA properties with visible cracking that has not yet progressed to structural movement, our concrete repairs SA guide covers the diagnosis and repair options that may prevent the need for underpinning. For SA structural repairs not requiring full underpinning, our structural repairs SA guide covers repair options for building elements damaged by reactive clay movement.

Causes of Foundation Movement in SA

Reactive clay soil movement is the dominant cause of foundation movement in Adelaide residential properties, but it manifests through several different mechanisms that require different interventions. Understanding which mechanism is driving the movement at a specific SA property determines whether underpinning is appropriate and, if so, which underpinning method addresses the actual structural problem. Our foundation repairs SA guide covers the full range of SA foundation remediation options including those that do not require underpinning. For SA shed slabs on reactive clay sites, our shed concrete slabs SA guide covers the reactive soil specification that avoids the movement problems underpinning is used to correct.

Seasonal shrink-swell movement is the baseline reactive clay behaviour that affects all Adelaide properties on H1 and H2 soils. The foundation moves up and down by small amounts each year as the soil moisture changes with the seasons. If the movement is uniform across the building, the structure rides the movement as a unit and no cracking or distortion occurs. If the movement is differential, different parts of the building move by different amounts and the structure is distorted. Differential movement on SA Class H1 and H2 sites typically produces cracking that follows a diagonal pattern through masonry walls, opening from the lower corner of a window or door frame toward the upper corner of the opening. This pattern reflects the rotational distortion of the wall as one footing rises or falls relative to the adjacent footing. Where adjacent retaining walls contribute to soil movement, our retaining walls SA guide covers retaining wall structural requirements on reactive clay sites. Our concreting services SA guide covers the full range of SA structural and decorative concrete services available from Adelaide contractors.

Localised moisture change is a more severe form of reactive soil movement driven by a specific moisture source near or beneath the building. Common localised moisture sources in Adelaide include leaking water supply or sewer pipes beneath the building, blocked or broken stormwater pipes directing water to the subgrade near the footing, garden irrigation systems that wet the soil beside the footing preferentially, and large trees whose root systems extract moisture from the soil beneath and beside the building asymmetrically. In all of these cases, one part of the building's subgrade soil is substantially wetter or drier than the other, creating a persistent differential that causes ongoing foundation movement rather than the seasonal up-and-down that characterises standard reactive soil behaviour. The direction and pattern of cracking, and its correlation with the location of the moisture source, provides diagnostic information that helps the structural engineer identify the cause before recommending treatment.

Inadequate original footing depth is the third major cause of foundation movement requiring underpinning in SA. Many Adelaide homes built before the widespread adoption of AS 2870 design standards in the 1980s and 1990s were constructed with shallow strip footings of 150 to 250mm depth that sit entirely within the reactive soil active zone. These footings have no stable bearing level below the seasonal moisture change zone and follow the full magnitude of soil movement with every wet and dry cycle. On Class H1 and H2 sites, this movement can be 20 to 50mm per cycle, sufficient to produce progressive structural damage over decades. Homes in suburbs such as Elizabeth, Davoren Park, and Morphett Vale built in the 1970s on reactive clay with footing depths that would never meet today's AS 2870 requirements are common underpinning candidates as they approach and pass the 50-year mark of cumulative reactive soil damage.

External loading changes and neighbouring construction can also cause foundation movement requiring underpinning. An extension added to a SA house that adds wall loads above the original footing capacity can cause the footing to punch into the soil or settle differentially. Neighbouring excavation that removes lateral support from a footing, or vibration from nearby heavy construction, can also contribute. These causes are less common than reactive soil movement in SA residential contexts but are worth confirming with the structural engineer as part of the diagnostic process, particularly for properties near recent major development activity.

Signs That Underpinning May Be Needed in SA

Foundation movement in SA buildings produces visible and measurable symptoms that SA homeowners can observe and document before engaging a structural engineer. The more specific and detailed the documentation the homeowner provides, the more efficiently the engineer can assess the situation and provide a diagnosis rather than starting from scratch. Knowing which symptoms are significant and which are not helps SA homeowners distinguish between normal minor concrete shrinkage cracking and progressive foundation-related structural movement.

Wall cracking is the most visible symptom of foundation movement in SA masonry construction. The significant indicators are crack width, crack pattern, and whether the crack is progressive. A diagonal crack through brick mortar joints, running from the lower corner of a door or window frame toward the upper outer corner of the opening, in a stepped pattern following the mortar joints, is a classic reactive soil foundation movement crack pattern. The crack width matters: a hairline crack less than 1mm wide is low priority; a crack 2 to 5mm wide is moderate priority requiring monitoring and structural assessment; a crack wider than 5mm or a crack that has progressed noticeably over a single season is a high priority requiring prompt engineering assessment. Marking the crack ends with pencil dates and measuring the width at the same location at the beginning and end of each season is the simplest crack monitoring method available to SA homeowners and provides valuable data for the structural engineer's assessment.

Door and window frame racking is another reliable indicator of foundation movement in SA homes. When a door that previously opened and closed freely begins to stick at the top or bottom of the latch side, the door frame has distorted from its original rectangular geometry into a parallelogram, which means the wall in which it sits has racked. In a timber-framed SA house, this racking indicates differential settlement of the footing below the racked section. In a brick-veneer SA house, the brick veneer cracking pattern should correlate with the door frame racking location. The combination of door racking at a specific location and diagonal cracking in the adjacent wall provides strong evidence for differential foundation settlement at that location.

Uneven or sloping internal floors are a third significant indicator. SA homes with concrete floor slabs that have developed a noticeable slope, where a marble rolled across the floor follows a consistent path toward a lower area, have experienced differential settlement of the slab or the supporting footing structure. A floor that was level when the house was built and has developed an increasing slope over years is experiencing progressive differential settlement, not simply construction imprecision. For SA houses with timber floor systems on stumps, stumps that have visibly moved down or tilted relative to their original position are direct evidence of footing movement.

Structural Assessment and Geotechnical Investigation for SA Underpinning

The structural engineer's assessment is the mandatory starting point for any SA underpinning project. No responsible underpinning contractor should agree to proceed without one, and no SA homeowner should commission underpinning work without a structural engineer's design and specification. The engineer's assessment establishes the cause of the foundation movement, the extent of the affected foundations, the underpinning method appropriate for the specific SA site conditions, and the remedial works scope. Without this assessment, any underpinning work is guesswork about both the cause and the solution.

A typical structural engineer's assessment for an SA underpinning project involves a site visit to inspect and document the cracking pattern, measure crack widths and directions, assess door and window frame racking, probe for soft ground conditions around the perimeter, and review available information about the original construction. The engineer will also review the drainage conditions around the building, the location of trees and gardens relative to the affected foundations, and any changes to the site since construction that might be contributing to moisture change in the subgrade. The fee for this assessment in Adelaide is typically $800 to $2,500 depending on the scale of the project and the engineer's scope.

A geotechnical investigation is typically required alongside or after the structural assessment for any SA underpinning project that will involve structural intervention rather than moisture management alone. The geotechnical investigation involves drilling or excavating test pits at strategic locations near the affected foundations, recovering soil samples, and determining the soil profile, reactive soil classification to AS 2870, and in some cases the moisture content at various depths to help establish the moisture gradient driving the movement. The geotechnical investigation also establishes what stable bearing level is available below the reactive soil profile, which determines the depth to which any new underpinning elements must extend. For Class H2 and E sites in Adelaide, where the reactive soil can extend to significant depth, the geotechnical investigation is essential for specifying the correct underpinning depth: a screw pile or mini pier that terminates within the reactive zone is not providing the stable bearing it is intended to deliver. For SA properties where moisture is entering through drainage failures rather than reactive soil, our stormwater drainage SA guide covers the drainage solutions that address the moisture source.

The cost of the structural assessment and geotechnical investigation combined is $2,500 to $6,500 for a typical SA residential underpinning project. SA homeowners who attempt to bypass this cost by accepting an underpinning quote without engineering documentation are accepting both the risk that the underpinning method is inappropriate for the actual soil conditions and the risk that the underpinning is unnecessary because a simpler moisture management intervention would have been sufficient. The investigation cost is a small and worthwhile fraction of the underpinning cost it precedes, and it is the only reliable basis for confirming that any proposed underpinning approach will address the actual cause of the movement on the specific SA site.

Mass Concrete Underpinning Method

Mass concrete underpinning is the traditional underpinning method that has been used on Australian buildings including SA homes for several decades. The process involves excavating a series of pits beneath the existing footing in a carefully sequenced alternating pattern, so that no two adjacent sections are unsupported simultaneously. Each pit is excavated to the required new bearing depth, a new concrete footing is poured in the pit and allowed to cure to full strength, and then the adjacent sections are excavated in sequence until the full underpinning run is complete. The new concrete bears at a deeper and more stable level than the original footing, extending the foundation to a depth where the reactive soil movement is reduced to an acceptable level.

Mass concrete underpinning is particularly appropriate for SA buildings where the original footing is sound but too shallow for the soil's reactive classification. The new concrete element extends the footing depth without replacing the original footing: the original footing remains in place and the new concrete is installed beneath it. On Adelaide Class H1 sites where original footings of 150 to 200mm depth are common in pre-1980s construction, extending to 400 to 500mm through mass concrete underpinning can substantially reduce the differential movement exposure by placing the footing base below the most active portion of the reactive clay profile.

The critical operational constraint of mass concrete underpinning is the sequential excavation requirement. The alternating pit sequence ensures that the building always has adequate support while any individual pit is open. If the underpinning contractor excavates adjacent sections simultaneously, the building can lose support over a continuous length of footing, creating a risk of progressive settlement or structural failure during the works. The engineer's underpinning specification will prescribe the pit sequence, maximum pit width, and timing between adjacent pours. A SA underpinning contractor who follows the engineer's prescribed sequence is managing the work safely; one who deviates from the sequence to save time is creating an unacceptable structural risk.

Mass concrete underpinning requires confined space excavation adjacent to and beneath the existing footing. In SA, the Work Health and Safety Act 2012 and SafeWork SA regulations govern confined space and excavation work, requiring risk assessment, appropriate shoring where required by the soil conditions, emergency procedures, and competent supervision of all excavation work. An underpinning contractor who does not have documented SafeWork SA compliant procedures for excavation and confined space work adjacent to occupied SA buildings is not operating to the required safety standard for this type of work.

Screw Pile Underpinning in SA

Screw pile underpinning has become a widely used method for Adelaide residential underpinning projects, particularly in the H1 and H2 reactive clay suburbs of the northern and southern metropolitan area. The screw pile is installed adjacent to or through the existing footing using compact hydraulic torque equipment that can work in the confined access conditions typical of established Adelaide suburban properties, without the need for the large excavations required by mass concrete or mini bored pier methods.

The screw pile underpinning process involves installing the piles to their specified depth at prescribed spacing along the affected footing run, then connecting the pile head to the existing footing using a steel bracket system that transfers the footing load to the pile. The connection bracket is cast into a small concrete pad poured around the pile head and the bottom of the existing footing, mechanically linking the existing footing to the new pile foundation. The engineer specifies the pile spacing, diameter, depth, and bracket design for the specific loading and soil conditions of the SA site.

The primary advantage of screw pile underpinning for SA reactive clay sites is the ability to reach stable bearing depth below the reactive soil active zone without large excavations. A screw pile installed through a 300mm wide side access in an established Adelaide suburb, reaching 2,500mm depth into stable soil below the H1 or H2 reactive clay profile, achieves a stable foundation bearing that mass concrete underpinning at equivalent depth would require a much larger excavation to provide. The installation generates no spoil and minimal vibration, which is important for occupied SA properties where minimising disruption to residents and minimising risk to the existing structure during works are practical priorities.

The load capacity of each screw pile is confirmed during installation by monitoring the torque required to advance the pile. The relationship between installation torque and pile axial capacity is well-established empirically and provides an in-situ quality confirmation that is unique to screw pile systems. The engineer specifies the minimum installation torque for each pile as a proxy for the design load capacity, and the contractor records the torque at final depth for each pile as part of the quality documentation. This capacity confirmation record, combined with the depth record for each pile, forms the quality documentation for the SA underpinning project. SA homeowners should request a copy of the pile installation records as part of the project documentation for the property's building file.

Resin Injection for SA Foundation Stabilisation

Polyurethane resin injection beneath existing SA building slabs and footings is a relatively recent addition to the SA foundation remediation toolkit, offering a less invasive alternative to structural underpinning for specific foundation movement scenarios. The technique involves drilling small-diameter holes through the slab or adjacent to the footing, injecting expanding polyurethane resin that fills voids beneath the slab or footing and partially densifies the adjacent soil, and monitoring slab level during injection to detect and control any uplift.

Resin injection is most effective for SA foundation situations where voids beneath the slab or footing are the primary driver of differential settlement: situations where the soil has eroded or contracted away from the footing underside, creating unsupported spans. For SA situations driven by ongoing reactive clay shrink-swell movement, resin injection provides partial and typically temporary improvement because the reactive clay continues to move seasonally regardless of any void filling that the resin achieves. The structural engineer's assessment must determine whether the movement is void-driven, in which case resin injection may be appropriate, or reactive clay movement-driven, in which case resin injection is at best a partial and temporary measure.

The costs for SA resin injection foundation stabilisation range from $3,000 for a limited intervention on a small slab section to $10,000 or more for a comprehensive treatment of a full house perimeter. The process is typically completed in one to two days and the structure can return to normal use within hours of completion. For SA homeowners weighing resin injection against structural underpinning, the relevant question is not which is cheaper but which addresses the actual cause of the movement at the specific SA site. The structural engineer's diagnosis is the only reliable basis for this decision, and any SA resin injection contractor who proposes the treatment without reference to a structural engineer's assessment of the cause has not provided an adequate basis for the recommendation.

Moisture Management as the First Response to SA Foundation Movement

Before any structural underpinning is commissioned for an Adelaide property, the question of whether the foundation movement can be arrested by managing the moisture conditions around the building must be answered by the structural engineer. In a significant proportion of SA reactive clay foundation movement cases, the answer is that moisture management alone is sufficient to stabilise the movement, and underpinning is unnecessary if the moisture source is correctly identified and addressed.

The most productive moisture management interventions for SA properties showing reactive clay foundation movement are: identifying and repairing any leaking water supply or sewer pipes in the vicinity of the affected foundations; redirecting garden irrigation away from the foundation zone, ideally to a location at least two metres from the building perimeter; connecting all roof downpipes to the stormwater system rather than allowing surface discharge adjacent to the footing; repairing or improving the site drainage to prevent stormwater from pooling against the building perimeter; and in some cases, installing a root and moisture barrier along the affected foundation edge to slow the rate of moisture change in the subgrade. The engineer and geotechnical investigator can assess which of these measures are relevant to the specific SA property's situation.

The monitoring period after moisture management corrections are implemented is important and is frequently skipped by SA homeowners who want rapid resolution of the problem. Reactive soil movement does not reverse overnight when the moisture source is corrected: the soil must re-equilibrate to its new moisture regime, which can take one to three seasonal cycles. The structural engineer should specify a minimum monitoring period with regular crack width measurements before a decision to proceed with underpinning is made. A monitoring period that shows crack widths stabilising and not progressing is evidence that the moisture management intervention has been effective. Crack widths that continue to grow during the monitoring period indicate either that the moisture source has not been fully corrected or that the movement has a structural cause that moisture management alone cannot address, requiring structural underpinning after all. Reactive soil movement does not reverse overnight when the moisture source is corrected: the soil must re-equilibrate to its new moisture regime, which can take one to three seasonal cycles. The structural engineer should specify a minimum monitoring period with regular crack width measurements before a decision to proceed with underpinning is made. A monitoring period that shows crack widths stabilising and not progressing is evidence that the moisture management intervention has been effective. Crack widths that continue to grow during the monitoring period indicate either that the moisture source has not been fully corrected or that the movement has a structural cause beyond moisture management.

The EPA SA provides guidance on stormwater management obligations for SA property owners, and the SA Water website provides guidance on leak detection and reporting for SA water supply and sewer infrastructure. For SA homeowners where the suspected moisture source is a shared sewer or stormwater pipe, SA Water's responsibility versus the property owner's responsibility for repair depends on the location of the fault relative to the property boundary, and SA Water should be contacted for assessment if a shared pipe fault is suspected.

SA Building Approvals for Underpinning Work

Underpinning is structural building work and requires a development application and building approval in SA before work commences. The development application for underpinning is typically a straightforward building application supported by the structural engineer's underpinning design drawings and specifications and the geotechnical investigation report. The application is assessed by a building certifier who reviews the structural engineer's design for compliance with the NCC and applicable Australian Standards, and issues the building approval on satisfaction that the design is appropriate and compliant.

The building approval for underpinning work typically includes staged inspection requirements: a pre-works inspection to confirm the conditions at the site match the assumptions in the engineer's design, and potentially staged inspections during the works at key stages such as after the first few pits in mass concrete underpinning or after a test pile installation in screw pile underpinning. The engineer may also conduct site supervision visits at critical stages. The certifier should be notified before work commences and at any point where conditions differ from those anticipated in the design. For mass concrete underpinning where each pit is poured in sequence and the structural performance depends on the correct sequencing, the certifier or engineer may attend multiple site visits over the course of the works rather than relying on a single inspection. This level of professional oversight during structural remediation work is appropriate given the consequences of an underpinning failure on an occupied Adelaide residence.: a pre-works inspection to confirm the conditions at the site match the assumptions in the engineer's design, and potentially staged inspections during the works at key stages such as after the first few pits in mass concrete underpinning or after a test pile installation in screw pile underpinning. The engineer may also conduct site supervision visits at critical stages. The certifier should be notified before work commences and at any point where conditions differ from those anticipated in the design.

The practical implication of the approval requirement is that SA homeowners who obtain underpinning quotes should budget for the development application fee (typically $200 to $600 in Adelaide metropolitan councils), the structural engineer's design fee, and the building certifier's fee in addition to the contractor's price for the underpinning work itself. Underpinning contractors who offer to proceed without a development approval are asking the homeowner to accept a compliance risk that could affect the property's insurance, its resale value, and the validity of the structural warranty on the underpinning works. The SA Government planning portal provides information on building approval requirements for structural remediation work across SA Local Government Areas. Disputes about underpinning work can be referred to Fair Trading SA under Australian Consumer Law.

Underpinning Pricing Across Adelaide - 2026 Guide

Underpinning pricing in SA is genuinely difficult to provide as a simple per-unit rate because the extent of works required, the method appropriate for the soil conditions, and the site access constraints all vary significantly between properties that appear superficially similar. The pricing below provides realistic ranges for the most common SA underpinning scenarios, but an accurate budget estimate requires an engineer's assessment and a site visit from the underpinning contractor before a reliable quote can be provided.

The total cost of an SA underpinning project includes the investigation, engineering design, building approval, and contractor works. For a typical Adelaide 3-bedroom house requiring partial underpinning of one or two walls following reactive soil movement, the total budget including investigation, engineering, approval, and works is typically $20,000 to $40,000. For a full perimeter underpinning of a larger SA home on a severe reactive clay site, $50,000 to $80,000 is a realistic total budget. These costs are substantial and reinforce why the investigation and engineering assessment that confirms underpinning is genuinely needed, rather than a less expensive moisture management correction, is a worthwhile investment before committing to works.

What to Look Out For in SA Underpinning Quotes

Underpinning quotes for SA properties range from properly engineering-backed proposals to contractor-only proposals that lack the structural engineering foundation that makes them reliable. The first and most important check is whether the quote is based on a structural engineer's assessment and design. A quote that is not based on a structural engineer's underpinning design is not a credible underpinning proposal for an SA reactive clay site.

Ask for the structural engineer's name, licence number, and firm on any SA underpinning quote. The engineer should be a registered engineering practitioner with specific experience in SA reactive clay foundation remediation. Ask also for the geotechnical investigation report that underpins the engineer's design: the soil classification, the depth to stable bearing, and the moisture content profile data from the investigation should all inform the underpinning method and depth specification. A contractor who cannot provide this documentation has not built the proposal on an adequate technical foundation for SA reactive clay conditions.

Confirm that the quote includes the development application and building approval process, and ask who is responsible for lodging the application and paying the approval fees. Some SA underpinning contractors include the approval process in their scope; others leave it to the homeowner to manage. Clarifying this before accepting the quote avoids gaps in the responsibility for obtaining required approvals before works commence. Ask specifically about the inspection program: at which stages will the certifier inspect, will the structural engineer visit site during the works, and what documentation will be provided after completion confirming the works were executed as designed. The quality of this post-completion documentation affects the value the underpinning adds to the property and its insurability. Verify contractor licensing at CBS SA.

Choosing an Underpinning Contractor in SA

Underpinning is one of the highest-risk residential construction activities for both the building and its occupants, and choosing the wrong contractor has consequences that range from inadequate remediation requiring repeat works to structural failure during the underpinning process. SA homeowners should apply more rigorous selection criteria to underpinning contractor selection than to most other trade engagements. The combination of excavation work beneath an occupied building, structural work affecting the building's foundation, and the need to follow a precisely engineered sequence of operations makes the professional experience and technical competence of the contractor the dominant selection criterion, ahead of price. An underpinning contractor who can clearly describe the sequence of works for the specific method being used, who has the correct equipment for the site access conditions, and who can provide references from comparable reactive-soil underpinning projects in Adelaide is demonstrating the combination of knowledge and experience that justifies engagement for structural remediation work on an SA residential property., and choosing the wrong contractor has consequences that range from inadequate remediation requiring repeat works to structural failure during the underpinning process. SA homeowners should apply more rigorous selection criteria to underpinning contractor selection than to most other trade engagements.

Verify the CBS SA Building Work Contractor licence before engaging any SA underpinning contractor. The BWC licence is mandatory for structural building work in SA and confirms minimum competency and experience standards. Check whether the licence is current and whether it covers the class of work involved. For screw pile underpinning, also confirm that the contractor is accredited by the screw pile manufacturer for the specific pile system being used: screw pile manufacturers including Geotech, Krinner, and Atlas maintain installation accreditation programs that confirm the contractor has received appropriate training and uses correct installation equipment and procedures.

Ask for a minimum of three references from completed underpinning projects in Adelaide suburbs with similar reactive clay soil conditions to the property being remediated. Contact those references and ask specifically whether the foundation movement was fully arrested after the underpinning, whether any additional movement or cracking appeared in the period following the underpinning, and whether the contractor managed the building approval process correctly and provided complete documentation. A successful SA underpinning project is one where the movement stops, the building certifier's approval was obtained, and the homeowner has documentation that confirms the works were completed to the engineer's specification. Public liability insurance (minimum $10 million) and workers compensation insurance are both essential confirmations before any underpinning contractor commences work on an SA property. Standards Australia publishes the Australian Standards relevant to underpinning and foundation remediation, and a contractor who references these standards in their method statement is demonstrating appropriate technical awareness of the regulatory framework for SA structural remediation work.