A Chartered Surveyor good with Floor Plans

We need someone to spend several hours each day on altering internal layouts of buildings from floor plans. We then need them scaled off to measure existing square footages. We also need the person to be able to add potential extensions and then calculate the total square footages. It is also best if they have time to attend property visits that our development company is pursuing to get a better idea of the project/extensions we wish to pursue. Kind Regards