Semi-3D/Isometric Floor Plan

We are a designer and supplier of Intelligent Building Automation/Control/Management Systems. For our GUI packages, we provide our clients with floor plans where we overlay information upon. Traditionally we provide 2D floor plans, but there is a general trend towards semi-3D floor plans. Even 2D floor plans can take some time to create, depending on the drawings provided to us and their original format. We are looking to cut costs and find a small group of freelancers who we can turn to for producing the floor plans to our general look and feel template, such that we can focus our own internal labour/resources on our core day-to-day operations. For the floor plans, sometimes we are provided complete DWG files, with many building services all overlaid into the same model. Generally speaking in these circumstances, we strip most layers away in order to generate a floor plan that is relevant for our purposes. Typically, we require the following: 1.) Base/Underlying Floor Plan - PNG, roughly 1800x900 px floor plan that shows a given floor's main architectural layout including walls, columns, doors and stairways. 2.) Mechanical Services Overlay - PNG, same size as underlying floor plan, that only has the mechanical equipment shown (ductwork, air conditioning boxes, supply air/return air registers). Often, source DWG files are unavailable, particular for older buildings. In most cases, we are provided with scanned to PDF of old drawings which have the architectural and mechanical features on it only; requiring us to manually sketch over the walls, doorways, ductwork, etc. Sometimes we have vectorized PDF floor plans which are a little easier to work with. Attached are 2 sample images of general look we are wishing to achieve with the PNG files. One of the samples is where only main architectural features are shown. The other sample is where both the main architectural features, as well as the mechanical services layers are both in the image. As described before, we would like to have the mechanical services layer as a transparent PNG as we use these as switchable on/off layers that are overlaid over the architectural layer. I have previously used an Indian company for this type of work, but have been frustrated with poor quality, such as doors sometimes not being shown, or walls shown where the original line was just an annotation line, etc. Accuracy, simplicity, consistency, and fast turnaround time are the objectives we are after.