Here's Kenney's Modular Building set ( http://kenney.nl/assets/modular-buildings )all modified to work in Asset Forge. There are 108 blocks in this kit all re-named to make searching easier in the next update.
These blocks are really only subitable for quickly making building exteriors so while it may be faster to make a house or office building using these you'll need to make the interior using something else. Additionally these have not been modified to be fit seamlessly with built in kits so if roofs from the City or Castle kit fit that's an added bonus but not at all planned. As seen in my other posts here using this set it does mesh well with the road kit, of which I need to set tile names before it's ready, and with some tiles from other sets.
Due to the number of blocks in this kit it may take a second for the folder to load in Asset Forge the first time you use it. This set serves as a decent benchmark for Asset Forge's performance as far as generating thumbnails goes.
I think some of the tiles/blocks can use better names to help group them in the selection pannel better so if you find any that shoud be named something different please let me know.
To add these blocks to Asset forge open the ZIP and copy the included "Buildings" directory to [Asset Forge Folder]/Collections .