Create draft architecture documents and 3D images

I want to make an extension to my 3rd floor flat that will require initial freeholder consent - in order to get this I need some basic plans drawn up for their approval before I move on to the full architecture phase. I have had some preliminary plans done about a year ago which I'd now like changed and these can be sent to you for modification. The extension will involve: - removing two sets of current fixed double windows to gain access to a balcony - installation of bi-folds approx 2.65m wide - installation of a dry wall to create a 2nd room The design brief is to create a simple mockup of draft plans and potentially 3D images of what the building work would look like so that the freeholder can approve us moving on to the next stage of official plans. As the building work will not be based on these exact plans they need to provide enough technical detail and conform to building regulations to get us approval but once approved we will move to the next level of detail. The deliverable will be: 1) modified plan based on the original now showing the addition of the bi-fold doors 2) some 3D images of potential change to balcony and room 3) "marketing" images for freeholder approval