Shoring is temporary work, but the consequences are not temporary.
The system may be required to retain soil, protect an adjacent foundation, support part of an existing building, keep an excavation open while a permanent wall is built, or provide a safe load path while underpinning or structural work proceeds.
For a Toronto building-permit application, shoring drawings and details may be required when the construction method needs them. Shoring, foundation and other structural drawings are submitted within the Building Permit set and can form part of a staged or part-permit review where applicable.
That permit context is only one layer. Construction safety requirements, geotechnical conditions, public right-of-way restrictions, neighbouring property constraints and the contractor’s means and methods can create separate responsibilities.
The useful first question is therefore not, “Which shoring system is cheapest?” It is: What must remain stable at every stage of excavation, and what information is reliable enough for the responsible professional to design that temporary support?
If the project mainly needs permanent structural design — for example new footings, beams, foundation walls or underpinning that will remain as part of the building — start with Structural Engineering. If a shoring package already exists and the issue is professional review of that existing design, the better starting point may be Engineering Review & P.Eng Stamp.
Different projects use the word shoring for very different temporary-work problems. Choosing the right path early prevents the permit drawing, excavation contractor and engineer from working from different assumptions.
The excavation itself needs temporary earth retention so soil, nearby foundations, utilities or road/property conditions are not left unsupported while the below-grade work is built. The design has to consider depth, property-line proximity, soil/groundwater, adjacent foundations, surcharge loads and the restraint strategy.
The ground may not be the main problem. A building element may need temporary support while a bearing wall, beam, column, foundation or other permanent component is removed, altered or replaced. The temporary load path has to coordinate with the permanent structural design and contractor sequence.
Underpinning can create both a permanent foundation-design problem and a temporary excavation-support problem. Permanent underpinning geometry and load transfer belong with Structural Engineering; this page owns the temporary support, excavation and construction-stage interface.
If shoring drawings already exist but the excavation method, site condition, contractor sequence or requested design has changed, the current package and new conditions need professional review before responsibility can be defined.
Shoring becomes an engineering issue when the excavation, support system or construction sequence can affect the stability of the excavation, adjacent structures, workers or surrounding property. The required approach depends on the actual site conditions and the support system being proposed.
| Project situation | What needs to be addressed |
|---|---|
| Excavation may affect an adjacent building or structure | The excavation-support strategy and the precautions needed to protect the adjacent structure should be professionally defined. |
| An engineered, prefabricated or hydraulic support system is proposed | The support system may require project-specific professional engineering based on the excavation and site conditions. |
| The excavation or trench reaches significant depth or width | The support system should be checked against the applicable Ontario requirements and designed for the specific project where required. |
| Actual soil or groundwater conditions differ from the design assumptions | The issued shoring design may need to be reviewed or revised before construction continues. |
| The contractor wants to change the issued shoring system or sequence | The proposed change should be reviewed against the engineering basis before it is treated as an acceptable field adjustment. |
The presence of one of these conditions does not by itself determine the final shoring system. The site, excavation geometry, geotechnical information, adjacent conditions and construction sequence still need to be considered together.
Send project context first, the next step can then focus on scope, information gaps and the right page or service route.
A shoring system cannot be selected responsibly from excavation depth alone. These inputs often control both the engineering concept and the project sequence.
Soil type, strength, groundwater and subsurface variability affect earth pressure, wall/pile behaviour, embedment, movement and system feasibility. A geotechnical report is not universal for every small project, but it can be a critical design input and Toronto Building may require one depending on the application.
A current survey or reliable property information establishes excavation limits, neighbouring structures and available working room. If a restraint concept depends on access or anchors outside the property, the required legal/property permissions must be confirmed separately rather than assumed from the engineering concept.
Depth is only one variable. Width, shape, stepped excavation, basement/foundation geometry, underpinning stages and the point when permanent walls/slabs can carry load all affect the temporary works.
Nearby footings, party walls, masonry, roads, sewers, watermains, transit structures or buried services can change the design, monitoring needs and external review requirements. Known, assumed and unverified conditions should be distinguished.
Water can change soil behaviour, access and excavation-support loads. Dewatering can also introduce settlement or municipal/environmental interfaces, so the shoring design should be coordinated with the available groundwater information and dewatering strategy.
Equipment, spoil piles, traffic, crane loads, adjacent foundations, material storage and staging can create surcharge or access constraints. The temporary system must work while excavation progresses and while braces, anchors or permanent construction are incomplete.
A shoring drawing is not complete if it only shows the system at the final excavation depth.
Temporary works change as construction progresses, and the intermediate stages can control the design.
The shoring scope may need to address excavation stages, bracing installation, temporary load transfers, and how the permanent structure interacts with the temporary system.
The contractor’s construction sequence is critical, since a system may be safe in its final condition but unstable during an intermediate stage.
There is no universal “best” shoring system for Toronto projects. The appropriate restraint system depends on excavation depth, soil and groundwater conditions, movement tolerance, property constraints, adjacent structures and the construction sequence.
Common systems include soldier piles and lagging, where vertical piles and lagging retain soil as excavation progresses, and drilled, caisson or secant wall systems, which may be considered where greater stiffness, movement control or groundwater management is required.
Other projects may use sheet piling or other continuous wall systems where soil conditions, installation access and vibration constraints allow. Where external restraint is feasible, tiebacks or ground anchors can support the shoring wall, but property boundaries and legal access rights must be confirmed before relying on off-site anchors.
If anchors are not suitable, struts, walers and internal bracing may be used, although these systems can affect excavation access, equipment movement and construction sequencing. Some projects may instead rely on rakers, cantilever action or localized temporary support, depending on the loads, geometry and construction stages involved.
The system should follow the site and the engineering requirements, rather than being selected from a standard detail before the project conditions are understood.
Shoring often touches more than one authority or professional responsibility. Treating one approval as if it covers everything can create a coordination gap.
Where the construction method requires shoring, Toronto’s permit framework can require shoring drawings and details as part of the building-permit documentation. Current electronic-submission guidance places shoring, foundation and other structural drawings in the Building Permit set and allows them to be extracted for part permits where applicable.
That does not mean every project receives a separate shoring permit or follows the same part-permit sequence.
Excavation protection and temporary support also sit within Ontario construction-safety requirements. Depending on the excavation and support system, engineered design, notices and other obligations may apply.
Those duties remain with the constructor/employer/project participants defined by the applicable legislation. A building-permit drawing does not replace construction-site safety responsibilities.
If piling, shoring or associated building operations extend into or occupy the public right-of-way, Toronto has separate construction-permit requirements for that work. The project should establish this before the shoring concept assumes space or access outside the private property.
Some projects create additional review requirements because of nearby transit infrastructure, major utilities, sensitive buildings, vibration concerns or other site-specific conditions. Toronto Building can also require professional geotechnical or vibration-impact reports depending on the project.
Identify those interfaces while the system is being designed — not after the shoring package is complete.
Shoring projects can involve several professionals and construction participants at the same time. The important point is to keep each role and professional responsibility clearly defined.
The professional responsible for the temporary-works design addresses the engineered support system within the agreed scope, such as support of excavation, temporary bracing or temporary load-transfer works.
The permanent-works designer remains responsible for the permanent building and foundation systems within their scope. Temporary and permanent works still need to be coordinated where loads, connections or construction stages interact.
Where required, geotechnical information provides the soil, groundwater and related design assumptions used for the shoring system. The engineering scope should make clear which geotechnical information and recommendations the design relies on.
The contractor or constructor remains responsible for applicable construction means, methods and site-safety obligations and for installing the work in accordance with the issued design. Field review may be a separate professional scope, so the project should also define whether it is included and what site visits, hold points or reporting are required.
Send project context first, the next step can then focus on scope, information gaps and the right page or service route.
The process should reduce uncertainty before excavation reaches the point where field changes become expensive or unsafe.
Start with the address, proposed excavation, permanent project and construction stage. Establish whether the main problem is earth retention, temporary building support, underpinning interface or an existing design that needs review.
Review the survey/site plan, architectural and structural plans, geotechnical information, adjacent conditions, utilities and known groundwater information. Identify what is missing before the design basis is fixed.
Define excavation geometry, surcharges, movement sensitivity, property-line limitations, construction access, temporary loads and the relationship to the permanent structure.
The responsible engineering scope develops the shoring/restraint strategy, calculations, drawings and construction stages or conditions that need to be followed.
Integrate the shoring drawings into the applicable permit package and identify whether right-of-way, geotechnical, vibration, infrastructure or safety-related processes need separate action.
The contractor builds to issued documents and raises discrepancies before changing the system. Where field review is included, the responsible professional reviews defined stages and documents findings within scope.
You do not need a complete engineering package to start the conversation, but the initial review is much more useful when the site and construction problem are clear.
You do not need a complete engineering package to start. The initial review is more useful when we can understand the site, excavation and current construction stage.
Start with the property address and municipality, together with any current survey or site plan showing property lines, nearby buildings and the excavation area. Send the most recent drawings or sketches showing the proposed excavation depth, foundation or basement geometry and the permanent construction being built.
If available, include any geotechnical, soil or groundwater information, as well as photos, surveys or records showing adjacent foundations, retaining walls, roads, utilities or other sensitive conditions that could affect the shoring approach.
If a contractor has already proposed an excavation method, staging sequence, equipment plan or restraint concept, send that information too. For projects already under review, include the full current shoring package and City comments, not just an individual comment or drawing page.
Finally, tell us the current construction stage. Whether the project is still preliminary, excavation is about to begin, shoring has already been installed or site conditions have changed can materially affect the next step.
Shoring can be one part of a larger project. Use the route that matches the permanent design, the state of the existing file and what has already happened on site.
Use this route when the primary need is permanent structural design — foundations, underpinning, beams, walls, columns or other elements that remain as part of the completed building.
Use this route when a shoring or temporary-works design already exists and the main question is professional review, revision and responsibility for the defined engineering content.
Use this route when work is already installed and the need is a professional site review, conformance opinion or letter based on the actual condition.
Use this route when shoring is only one part of a larger permit package and the architectural / building-permit drawing base still needs to be prepared or coordinated.
Send project context first, the next step can then focus on scope, information gaps and the right page or service route.
Answers to common questions before excavation or temporary support is designed. Project-specific engineering still depends on the site, ground conditions, construction sequence and defined professional responsibility.
Shoring design is the engineering of temporary support used during excavation, demolition, alteration, underpinning or construction before the permanent structure can safely carry the required loads. The scope can include earth retention, temporary bracing, load transfer, support details, calculations, construction stages and field-review requirements depending on the project.
The answer depends on the excavation, soil, depth, adjacent structures, worker exposure, temporary-work configuration and the permit/safety requirements that apply. Toronto can require shoring drawings where the construction method uses such a system, and Ontario construction-safety regulations identify cases where support systems must be engineered. Review the actual project rather than relying on a generic depth rule.
No. Underpinning is usually permanent foundation work intended to extend, strengthen or alter an existing foundation. Shoring is temporary support used during construction. They can occur on the same project, and the temporary shoring/excavation sequence may need to coordinate closely with the permanent underpinning design.
They can be. Toronto’s current submission guidance places shoring, foundation and other structural drawings within the Building Permit set and notes that they should be capable of extraction for part permits where applicable. The exact permit sequence depends on the project.
Not every small project follows the same documentation path, but geotechnical information can be fundamental because soil and groundwater conditions affect loads, movement and system behaviour. Toronto Building can also require a geotechnical report for certain permit applications. The designer should identify the geotechnical basis rather than guess at it.
That cannot be assumed from the engineering concept alone. Property boundaries, access and legal rights can affect whether off-site anchors are feasible. The project team should confirm the necessary permissions separately. If external anchors are not available, the engineering concept may need to consider internal bracing, rakers, cantilever action or another project-specific strategy.
Sometimes, but an in-field change can affect loads, movement, adjacent property and the construction sequence. The responsible professional should review the current site condition and proposed change before the system is modified. Do not treat a structural change to temporary works as an informal field adjustment.
