He succeeds Mark Oliver who is leaving the company after more than eight years at the helm.
Forsyth was most recently Chief Executive Officer at IAC Acoustics and previously Group Managing Director for the Wavin Groups’ South West Europe operations.
He will lead H+H’s business in the UK from May 1.
Oliver is leaving to become CEO of smoke controls specialist the Colt Group.
Forsyth said: “I am excited to be joining H+H to build on the strong legacy that the H+H Management team have created under Mark’s leadership.
“The business has been through a major turnaround to become the clear market leader and a very successful business. Through my experience I believe I can bring further value to H+H UK and build on its success.”
Michael Andersen, Group Chief Executive Officer, said “We welcome Calum to the H+H Group to lead our UK business into its next phase of development which will include upgrading our Borough Green plant to make it the most advanced aircrete facility in the UK.
“With the country’s homebuilding sector continuing to grow, this is an exciting time for H+H.”