How to download geodata from a fis broker wfs (web feature server) via qgis and save it as a shapefile.

1. Go to fis broker
2. Choose one of the data sets. For example 'Hausumringe'.
3. Click 'Zum Downloadlink (WFS)'
4. Look for the 'Rechneradresse' point. Its an url like this one for the house-shapes in Berlin: http://fbinter.stadt-berlin.de/fb/wfs/geometry/senstadt/re_hausumringe

1. Download WFS client plugin. You can install it via QGis by this steps: 'Plugins' -> 'Manage and Install Plugins...' -> search for 'wfs' -> choose 'WFS 2.0 Client' -> 'Install Plugin'
2. Download Geodata. Open the plugin by clicking on 'Web' -> 'WFS 2.0 Client' -> 'WFS 2.0 Client'. Type in an url of a WFS. For example : http://fbinter.stadt-berlin.de/fb/wfs/geometry/senstadt/re_hausumringe. Click on 'Get Capabilities'. After that you can define a bounding box, a feature limit and a SRS (spatial reference system). For the datasets of houses you must choose featureCount = 550000 and SRS = EPSG:4258. SRS = EPSG:25833 should always work for the Berlin datasets.
3. Save as shapefile

If you need to convert the srs of the shapefile you can do it with the help of ogr2ogr: This command converts input.shp(SRS = EPSG:25833) to output.shp(SRS = EPSG:4326).

$ ogr2ogr -t_srs EPSG:4326 -s_srs EPSG:25833 output.shp input.shp

Get information of the different spatial reference systems at http://epsg.io/