Some had been impacted by the loss of the building, and the community had wanted to help the group "rebuild".
Gender Dynamix chairperson Maddie Stubbins said the fire had a financial and emotional impact on the community.
"It was a safe space we developed and created for the gender-diverse and rainbow community and as such its loss was devastating."
Many of the people it worked with have been victimised, she said, and have struggled with being their authentic selves.
Gender Dynamix continued to serve the community from its other building at the Historic Village.
In the three months to September, it maintained 1100 individual face-to-face contacts via clinical or peer support avenues.
Stubbins said while it received funding from government agencies, its main sources of income came from fundraising and grants.
Money received from these went towards staff training, food and supplies for group sessions, trans pride and other celebrations, upgrading of its facilities and office space, presentations to medical, community and educational services and advocacy services plus things like vehicle and travel costs.
"Roller Derby is an inclusive sport that has often supported our community. I personally have been involved as a referee for nearly 10 years and have transitioned during this time."
She said they were thrilled that the Tauranga, Rotorua and Hamilton roller derby leagues were supporting them by running the event.
"We would love to see as much support as possible there for our community and it's a chance to watch some hard-hitting roller derby action and have fun."
It was also announced this week Rainbow Youth received funding through the Government Rainbow Wellbeing Legacy towards the rebuild and re-establishment of its Te Moana a Toi Bay of Plenty drop-in centre and services.
When asked what people might expect if they have never watched roller derby before, Morrow said her husband described it as exactly like car derby, but with people in skates.
"It can be fast. Very fast."
She said it was not "pretty" skating, and skaters scored by passing others. That was where the contact came in.
There will be two games on the day, with the first starting at 2pm when the Sulphur City's Motley Crew take on Team Crazy Legs "Skating out for invisible illness".
The second game will see Sulphur City Steam Rollers racing Moana Roller Derby at 4pm.
Entry is $5 per person and under-5s are free.
There will also be spot prizes, a bake sale and a raffle. Derby merch will be on sale.
The event is on November 19 at the Queen Elizabeth Youth Centre.
