Deputy Prime Minister Angela Rayner also joined the visit.
They visited Newquay Orchard - meeting volunteers, staff and pupils, learning more about the services the CIC offers on site.
Their next stop took them to the Nansledan housing development - and Nansledan School where pupils were waiting to greet them. King Charles reportedly wanted to show the PM and Deputy Prime Minister a project that promotes both traditional materials and sustainable living.
Final journey for Intercity 125
Wishing Well unveiled in Newquay as tributes paid to Lions volunteer
Rail line reopens
Driver jailed after unsecured drilling rig caused crash that killed Newquay woman
The future of Newquay Zoo is secured after new owner is revealed
Newquay Health Centre invites residents to meeting on renovation plans
Boat declared a wreck and dismantled after sinking in Newquay Harbour
Newquay businesses join forces to support families this Christmas
Newquay cliff rescue captured in dramatic photos
Cornwall braces itself for named Storm Bram
Torrential rain causes flooding and travel disruption across Cornwall
Reclaim the Night vigil to highlight digital and online abuse of women
New real-time water testing device demonstrated at Fistral Beach
Santa Bus heading to Newquay this weekend
Man rescued from cliffs in Newquay
Banking returns to Newquay’s town centre as new Banking Hub opens on Bank Street
Next phase of Mid Cornwall Metro scheme given green light despite opposition
Thrill seekers set to take the plunge this New Year
Christmas carol concert to bring festive cheer to Newquay
Full line-up of Christmas events in Nansledan this week