Notice of Half Year Results

10 December 2025

ALUMASC GROUP PLC

("Alumasc" or "the Company")

Notice of Interim Results and Investor Presentation

Alumasc Group PLC, the premium sustainable building products, systems and solutions group, will publish its results for the six months ended 31 December 2025 ('Half Year Results') on Tuesday, 3 February 2026.

Paul Hooper, Chief Executive, and Simon Dray, Group Finance Director, will provide an in-person presentation to sell-side analysts at 9am GMT on Tuesday, 3 February 2026, this will also be available via Zoom. If you would like to attend, please RSVP to [email protected].

There will also be a live presentation relating to the Company's Half Year Results via the Investor Meet Company platform on Tuesday 3 February 2026 at 3pm GMT. The presentation is open to all existing and potential shareholders. Questions can be submitted in advance via the Investor Meet Company dashboard up until 9am the day before the meeting or at any time during the live presentation.

Investors can sign up free of charge to Investor Meet Company and meet Alumasc via:

https://www.investormeetcompany.com/alumasc-group-plc/register-investor

Investors who already follow ALUMASC GROUP PLC on the Investor Meet Company platform will automatically be invited.

A recording of the presentation and a copy of the slides will be available following the event on the Company's website at https://www.alumasc.co.uk/investor-relations.

END

Enquiries:

The Alumasc Group plc

Paul Hooper (Chief Executive) +44 (0)1536 383844

Simon Dray (Group Finance Director)

Cavendish (Nominated Adviser & Joint Broker)

Julian Blunt, Edward Whiley (Corporate Finance) +44 (0)207 908 6000

Tim Redfern (ECM)

Peel Hunt (Joint Broker)

Mike Bell +44 (0)207 418 8831

Ed Allsopp

Camarco (Financial PR)

Ginny Pulbrook +44 (0)203 757 4992

Tilly Butcher +44 (0)203 757 4991

[email protected]

About Alumasc:

Alumasc is a UK-based supplier of premium building products, systems and solutions. Around 80% of group sales are driven by building regulations and specifications (developers/housebuilders, architects and structural engineers) because of the performance characteristics offered.

The Group has three business segments with strong positions and brands in their individual markets. The three segments are: Building Envelope; Water Management; and Housebuilding Products.