Good day, and welcome to the Metro Performance Glass full year results announcement conference call. At this time, I would like to turn the conference over to Simon Mander. Please go ahead, sir.
Good morning. Welcome, and thank you for joining our call today. My name's Simon Mander, and I'm the CEO of Metro Performance Glass. With me is our CFO, Brent Mealings. This morning, we'll provide you with an overview of the group's results for the 12 months to the 31st of March 2022, and then we'll be happy to take any questions. Turning now to slide two, we've noted four key messages which summarize the year. I'd just like to start by recognizing the dedication of our people right across the Metro Glass Group. The continued impact of the COVID-19 pandemic presented significant challenges for our teams. Their resilience has ensured that we've continued to deliver our market-leading products and services to our customers.
The COVID-19 Alert Level four shutdown during the first half cast a shadow over the financial year, with an immediate impact of the lost production days and the flow on impact on inventory holdings, supply disruption, and escalating input costs. Australian Glass Group progressed on their turnaround plan with stable operating performance, delivering a modestly improved EBIT result in the face of COVID-19 and the heavy flooding in New South Wales. While our net debt has increased this financial year, we've built buffer into our inventory levels to deal with ongoing supply chain disruption and invested in a series of capital items that are set to improve our capacity, quality and capability for the future home insulation changes in both New Zealand and Australia. On slide three. I'm proud of the progress we've made in our environmental, social and governance commitments to the wider community.
Our safety performance continues to improve, and this remains a key focus for the leadership team. Our apprenticeship scheme provides development opportunities for our people to grow. 79 staff are currently enrolled in the program, and eight apprentices qualified during the year. We've begun our environmental sustainability journey. Our focus for the coming months will be on understanding our environmental footprint and how we can reduce that footprint over time, and the related disclosures that will be required for future reporting periods. We remain firmly focused on our customers and our people, making good progress with both. Now, moving to our key financial results for FY22 on slide four. Group EBIT of NZD 5.9 was at the low end of our range of February guidance. The result was impacted by a difficult trading month in March, coinciding with the peak of the Omicron outbreak in New Zealand.
Now, while I appreciate that Metro is not alone and many businesses have been significantly impacted by Omicron, I'd just like to give some idea of the extent of this disruption to our teams. In New Zealand, we've had 40% of our staff test positive for COVID this calendar year, and in Australia, 50% test positive during FY22. All were required to isolate for 7-10 days. The willingness of our staff to be flexible during this period has been much appreciated, as has the support and understanding of our customers. The impact of the COVID-19 Level 4 shutdown on the New Zealand business during the year was severe. The rapid escalation of input costs also had a significant impact on profitability compared to last financial year.
Our leverage ratio is above our capital management targets disclosed last financial year, and consequently, our focus for FY23 will be on essential capital only and debt reduction. While net debt has increased from last year, we built contingency in our inventory holdings to navigate ongoing supply chain disruptions and invested in future capital equipment capability in both New Zealand and Australia. On slide five. New Zealand revenue was NZD 178 million, down 1% versus the previous comparable period, with an EBIT before significant items of NZD 7.4 million, down 61%. While the earnings result was disappointing, there were some encouraging developments for the future as our market share in the important window manufacturing segment was stable throughout the year, and retrofit continued to grow its contribution to the group.
During the back end of FY22, the New Zealand business announced a series of price increases on the market, with a focus on returning the business to an acceptable gross profit performance heading into Q2 FY23. This year has provided further proof of the importance of our strong customer relationships and our continual focus on improving our service model and customer experience. Our six-monthly customer survey results reinforce that we're on the right track, with New Zealand receiving its strongest rating to date. On slide 6. Pleasingly, we continue to see the demand for double glazing increase, with Australian Glass Group's revenue growing by 11% to AUD 58.1 million, with strong performance from all states.
At an EBIT level, after a difficult second half of FY21 and first half of FY22, AGG improved their performance for the second half of FY22 by AUD 1.5 million compared to the prior period, despite the ongoing COVID-19 issues and weather events. The trajectory for the business is exciting as we close in on the National Construction Code changes in energy efficiency due to be released during FY23. I'll now hand over to Brent to discuss the financial results in more detail.
Thanks, Simon, and good morning, everyone. Just a quick acknowledgement of the results released this morning being unaudited. Both MPG and the audit team have had challenges through the process with COVID-19. We expect an unqualified audit opinion and the annual report to be available in the coming days. On slide 7, we break out our revenue for the group, and you can see an overall increase of 2%. Our commercial glazing business was under pressure this financial year as the site access restrictions brought about by COVID-19 and the broader supply and labor constraints hampered our ability to execute. Our retrofit business revenue grew 16% year-on-year, which has been a positive contribution to the group. Slide eight reflects our full year results. I'll draw you to the segmental results on the right-hand side of the page.
The impact on New Zealand's gross profit margin was driven by rapid increases in input costs through the back end of 2021, as material shortages and global supply chain disruption drove prices up. In Australia, gross profit margin increased by 32%, reflecting the increase in focus on double glazing and a smaller overall negative impact of COVID relative to last financial year. Turning to the group results on the right-hand side, our net profit after tax, but before significant items decreased from NZD 7.2 million to a loss of NZD 500,000 in the twelve months. I'd like to move to the waterfall on slide nine. Movements in New Zealand's EBIT result are shown in the gray shading.
Our New Zealand EBIT result was NZD 11 million lower than the prior year as a result of the shutdown period impacts relative to last year and the rapid escalation of input costs that we were unable to offset by market price increases at the same rate and timing. The New Zealand business also incurred NZD 1.2 million in detention costs due to a buildup of imported glass containers during the back half of 2021, which was a direct result of the lockdown period. We have continued to focus on our cost base to mitigate the inflationary cost pressures. Turning to the Australian performance, which is in the green shaded area of the waterfall, the encouraging story here is the gross profit improvement that has largely offset the inflationary cost pressures. Turning to the balance sheet on slide 10.
Net operating cash flows were below last year with the reduction in overall group earnings. We invested in working capital in FY22 as safety levels for raw glass inventory have been progressively increased in response to ongoing international shipping disruption. Net debt increased by NZD 4.3 million year-over-year, which along with the reduced twelve-month trailing EBITDA, has impacted our net debt to EBITDA ratio. The business will be focused on bringing the absolute net debt down during FY23 through earnings growth and a focus on essential capital spend. Simon?
Thanks, Brent. Turning to slide 11. I'd just like to remind our investors of the company's capital allocation framework. This framework continues to guide our decision-making process on uses of our net operating cash flow. For FY23, we will be directing net operating cash flows to essential CapEx and net debt reduction. Turning now to our outlook for FY23 on slide 12. Our view is at the record level of consent through 2021 and early 2022, and the continuing capacity constraints on the industry support a consistent level of activity for the rest of the calendar year. The residential segment in New Zealand will continue to be competitive and dynamic. In Australia, we are confident that AGG continues to embed the improvements achieved in FY22.
The level of residential approvals in Australia have been strong during 2021, which alongside the increasing double glazing penetration, will provide support through the 2022 calendar year. Through a series of already announced price increases in New Zealand and Australia, the group is focused on improving gross profit margin performance through FY23. The group remains alert to COVID-19 risks and the significant disruptions in international shipping. Both are likely to continue until the end of 2022. We believe we're very well positioned to meet the requirements and opportunities presented with the upcoming changes in the New Zealand and Australian building insulation regulation code changes.
Finally, on slide 13, Metro Glass' strategy and focus remain unchanged as we continue to build resilience and defend our leadership position in a competitive New Zealand market, and to grow and improve the profitability of our Australian business and benefit from increasing demand for double glazing, and to ensure our balance sheet is strong and sufficient to cope with future risks and opportunities. Now, that brings us to the end of our presentation.