Rendering huge, interactive SVGs in a browser

We have to display huge SVG documents (about 20mb) inside a web application. Users should be able to zoom in and move the image.

Rendering the SVG directly as a DOM object is too slow and the performance is inconsistent. The same applies for painting it on a canvas.

Generally, handling SVG on the client side seems weak. So I thought of implementing a server-side solution for providing the data in small chunks, in a non-vector format. If the user is not interacting with the document, the buffer starts lazy loading higher detailed pieces. My concern with this solution is, that the network traffic could be critical.

We will be rendering 2D DWG / DXF files, which will be converted to SVG.

How would you solve this? Are browsers even built for handling huge vector graphics?