The development, Queens Manor, used to be the former Queen Mary's School for Girls, Clifton Drive South, Lytham.
The site is now home to luxury new housing which is being built by Barratt Homes.
The official open day is being held tomorrow (Friday).
In last week's Express, we announced it was to be held on Saturday, but this date has, in fact, been changed to Friday.
Civic dignitaries from Fylde are being invited to the special event, as well as members of the public.
The event is commencing at noon.
However, the civic party will be officially arriving at 12.30pm.
Those people interested in attending should go along to the show home from noon.
Spokeswoman Fiona Dootson said: "This is the official open day for this unique and amazing development and the show home.
"However, the show home will, of course, be available to view on subsequent days after August 8."
Light refreshments and champagne will be available.
Earlier, the Express reported how the developer felt 'old girls' of Queen Mary School may be interested in going along and taking a look at their former school and how it has changed.
However, it is not an official Queen Mary reunion event, although any old girls are, of course, welcome to attend independently.