Large Panel System (LPS) Buildings: Ensuring Structural Stability in Older Blocks
Many mid-century tower blocks in the UK were built using Large Panel System (LPS) construction a method popular in the 1960s and 1970s for its speed and low cost.
But several tragic events, most notably the 1968 Ronan Point collapse, revealed weaknesses in some LPS structures. Today, these buildings are under close scrutiny by the Building Safety Regulator (BSR) as part of the Building Safety Act 2022.
If you own or manage an LPS tower especially one over 18 metres or seven storeys, classed as a Higher-Risk Building (HRB) it’s essential to have its structural stability assessed and actively managed.
Understanding LPS Construction and Its Risks
- What is LPS?
LPS construction involves large precast concrete wall and floor panels connected on site, creating a frame without continuous reinforcement. - Why it’s vulnerable:
Many early LPS systems relied on weak panel-to-panel connections and lacked robustness against unusual forces. Over decades, exposure to weather and corrosion can further reduce strength. - The Ronan Point lesson:
In 1968, a gas explosion in a 22-storey LPS tower in London caused a progressive collapse, killing four people. The disaster exposed how local failures in LPS buildings can spread dramatically.
Key Structural Issues in LPS Blocks
- Weak joints or inadequate tying between panels.
- Corrosion of steel connectors or reinforcement at panel edges.
- Lack of robustness against abnormal loads (e.g., gas explosions, wind, or fire).
- Material deterioration due to age and water ingress.
These factors can compromise a building’s ability to resist disproportionate collapse where a small failure leads to a much larger structural breakdown.
Regulatory Expectations for LPS Owners
Under the Building Safety Act 2022, the Principal Accountable Person (PAP) must:
- Demonstrate that structural safety risks have been identified and managed.
- Include robustness assessments in the building’s Structural Safety Report (SSR).
- Take reasonably practicable steps to strengthen or monitor vulnerable connections.
- Keep an updated Golden Thread of evidence showing continued structural oversight.
Failure to address known LPS weaknesses could delay your Building Assessment Certificate (BAC) or trigger enforcement by the BSR.
How to Manage LPS Structural Risks
- Commission a detailed structural safety appraisal:
A competent structural engineer will review original design drawings, inspect joints and connections, and, if needed, conduct targeted opening-up works or testing. - Assess robustness against disproportionate collapse:
Evaluate whether the structure can resist abnormal events such as gas explosions or fire. - Strengthen or retrofit connections if required:
Modern strengthening techniques can significantly improve safety. - Plan ongoing inspections and maintenance:
Monitor critical joints and panels for corrosion, cracking or deterioration over time. - Keep records regulator-ready:
Document assessments and remedial work in your Safety Case Report and Golden Thread.
How Structures Made Easy Can Help
At Structures Made Easy, we have extensive experience assessing and reporting on LPS buildings for compliance with the Building Safety Act. We provide:
- Chartered Structural Engineer-led appraisals tailored to LPS risks.
- Detailed robustness and disproportionate collapse analysis.
- Practical recommendations for connection strengthening and monitoring.
- BSR-ready Structural Safety Reports to support your Building Assessment Certificate.
- Fast turnaround and portfolio pricing for landlords with multiple LPS blocks.
We make compliance clear, actionable and cost-effective, helping you protect residents and satisfy the regulator.
Related articles
Download a structural safety report starter guide with Structures Made Easy Ltd.
Why choose us?
With over 3000 successfully completed projects to date, we have consistently proven ourselves to be a leader in the industry. From design cross check procedures to quality control measures, we will ensure your project is completed to your exact specifications.
100% Success in Building Regs
Fully Qualified SE
Transparent Fees
Practical & Efficient Designs
Clear Advice
Fast Turnaround
We make all our processes as simple as
possible giving you peace of mind
STEP 1
Get a quote. Refer to enquiry form or email or speak to engineer
STEP 2
Arrange site inspection
STEP 3
Report delivered