We will refer to some presentation slides today as well as to the earnings release, which we issued this morning. We have also posted the slide presentation and the earnings release under the investor tab on our website. In our earnings release and filings, we reconcile these non-GAAP measures to GAAP measures. Jennifer will provide her perspective on our performance, current market conditions, our multi-year growth initiatives, and go over our revised outlook for 2026 before we open the line for any questions.
Our consolidated first quarter financial results are provided in today's earnings release. Consolidated adjusted EBITDA for the quarter was $126.3 million, up $41.2 million or 48% compared to last year. That translates to a margin of 20.2% in Q1 this year, up 190 basis points compared to last year. GAAP diluted EPS for the quarter was $1.14 per share, up $0.39 per share or 52% compared to last year.
On an adjusted basis, EPS for the quarter was $1.18 per share, an increase of $0.42 per share or 55% from last year. Orders for the quarter were $623 million, up $55 million or 10% from last year, contributing to a backlog at the end of the quarter of $1.04 billion. ESG's adjusted EBITDA for the quarter was $113.3 million, up $35.8 million or 46% compared to last year. That translates to an adjusted EBITDA margin for the quarter of 21.3%, an improvement over 130 basis points compared to last year.