Wellhöfer is a leading manufacturer of airtight attic hatches, wall hatches and space saving stairs. The company was founded in Würzburg Germany over 60 years ago. They were certified as a climate neutral operation in 2019. Test results for pollutants showed that their attic hatch and stairs have a rating 9 times lower than the “harmless” level required by the Sentinel Haus Institut, while the formaldehyde emission value is recorded at being 16 times lower. The company developed the first attic hatch to be certified Passive House Institute. .