The Ashwood Suite is a 14-bed extension of the Memory Lane facilities.
Stockport mayor, councillor Peter Burns, attended the event and cut the ribbon to formerly open the facilities.
A tree was also planted to commemorate the day. It had a plaque which the mayor unveiled.
This was not the only cause for celebration, as four senior carers, Kelly Rhodes, Karen Carling, Jenny Holmes and Joyce Elderkin were awarded with certificates for NVQ level 3 in dementia care.
They are the first people in the country to receive the commendation.
A further celebration was to 100th birthday of Betty Beasley, who received a card from the Queen. She was also given a bouquet of flowers and her sister came from Wales to visit on her special day.
Kathleen Jeffs, activity manager at Arbour Court, told the Stockport Express: "Betty is happy and contented living at Arbour Court and had a lovely day for her 100th birthday celebrations, if not tiring!"