Selling project of family house with living attic space about disposition

I am selling a project for a family house with an attic living area featuring 6+kk layout. The built-up area is 108 m², total floor area is 162 m². Heating options include heat pump or biomass (wood, wood chips, pellets) in automatic boiler unit. Underfloor heating has been considered.
The design documentation was prepared and includes all necessary calculations, technical reports (fire safety, electrical), valid energy label and will be handed over both printed and digitally. The designer waived their copyright rights so there's nothing preventing use and modifications of this documentation originally written under my name. I can provide more information via email or phone call.