St Scholastica’s College Redevelopment
Post-tensioning design and construction for a major education redevelopment in Glebe
Interspan delivered the design and construction of approximately 1,513 m² of post-tensioned concrete slabs across five levels for the redevelopment of St Scholastica’s College in Glebe, Sydney.
Working for Grindley Construction, Interspan provided an integrated post-tensioning solution designed to support the construction of a contemporary, multi-level education facility within the College’s established heritage campus.
Supporting a contemporary learning environment
The redevelopment represents a major expansion and upgrade of the facilities available to students and staff at St Scholastica’s College.
The new terraced building accommodates a broad range of teaching, performance, and shared spaces, including music and drama studios, science laboratories, seminar rooms, flexible learning areas, a library, a café, and canteen facilities.
A new covered outdoor learning area creates a central gathering point on campus, while the music amphitheatre connects the building’s internal and external spaces.
The redevelopment was carefully planned to introduce modern educational facilities while preserving the College’s established heritage character, green spaces and important view corridors.
Interspan’s scope
Interspan was engaged by Grindley Construction to provide a complete design-and-construct post-tensioning package for the five-storey development.
The scope included:
- Post-tensioning design and documentation
- Supply and installation of the post-tensioning system
- Design coordination and construction support
- Responses to RFIs and site queries
- Extension and stressing sign-offs
- Detailed reinforcement tracking within the project drawings
The post-tensioned structure was designed using RAPT and RAM Concept, with a specified concrete strength of 40 MPa.
Design coordination and buildability
Interspan’s in-house engineering and drafting teams worked closely with the project team to support buildability, construction sequencing and efficient delivery.
Streamlined design and drafting processes enabled timely responses to RFIs, construction queries and evolving site requirements. Reinforcing bar tags were also incorporated into the drawings to provide detailed reinforcement identification and tracking throughout construction.
Through disciplined project planning and coordination, Interspan completed its post-tensioning works within the required construction program.
Quality assurance and traceability
Installation was undertaken by Interspan’s CARES APT04-accredited post-tensioning team, whose personnel complete regular training and competency assessments.
Interspan’s quality assurance systems provide traceability throughout the delivery process, from procurement and supply through to installation, stressing and project completion.
These systems operate within Interspan’s certified management framework:
- ISO 9001 – Quality Management
- ISO 45001 – Occupational Health and Safety
- ISO 14001 – Environmental Management
Project details
Project: St Scholastica’s College Redevelopment
Location: Glebe, NSW
Sector: Education infrastructure
Builder: Grindley Construction Pty Ltd
Post-tensioning contractor: Interspan
Consulting engineer: MYD Consulting
Delivery model: Design and construct
Post-tensioned area: Approximately 1,513 m²
Building height: Five storeys
Concrete strength: 40 MPa
Image Credit: Grindley Construction
Interspan
Interspan uniquely integrates in-house post-tensioning expertise, advanced forensic diagnostics, and cutting-edge strengthening technologies to enable a single-source delivery model trusted by global developers for complex retrofit and reuse projects.
NEW STRUCTURES
The Interspan Group brings unique expertise in post-tensioning, construction methodology, and lifting operations that reduce CO₂ emissions, material usage, and construction program.
EXISTING STRUCTURES
We specialise in helping clients extend the lifespan of concrete structures through advanced repair, strengthening, and carbon-fibre solutions. Adaptive reuse projects are a perfect fit for our expertise, helping to minimise waste while delivering safe, modern outcomes that support community growth.
Over the last decade, the Interspan Group has become a market leader in the application of CFRP-strengthening solutions, with notable projects including the award-winning The Space House in London and the Quay Quarter Tower in Sydney.
Quality Assurance
Quality Assurance holds immense significance for Interspan because it impacts the safety of our operatives and future occupants, the long-term durability of our structures, and our client satisfaction and relationships.
Interspan is accredited under CARES APTO1 for the Production and Supply of Post-tensioning Anchorage Systems and is the only post-tension contractor in Australia accredited under CARES APTO4 for the supply and installation of Post-tensioning systems in concrete structures.
Sustainability
Post-tensioning and adaptive reuse are powerful design approaches that reduce material use and embodied carbon—delivering more efficient, resilient, and sustainable structures for the future.
Australia – NSW
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