New Zealand's housing is cold, damp, mouldy. Lack of heating and insulation means that homes are ill-equipped to deal with winter temperatures. These poor conditions are linked to increased illnesses and infection. Our homes are making us sick.

To fix a problem (and convince people to fix it) you must first measure it.

Whare Hauora trust uses sensors to measure the temperature and humidity of a room. The sensors must be:

• Very low cost

• Respect the privacy of the occupant

• Be, look and feel friendly and safe

For a subset of the deployments, they must work:

• without internet

• without power supply

Whare Hauora is working with residents of social housing, and to empower those who currently have the least power over their living conditions.

This talk is about the journey to create Whare Hauora, the technology we used, and the generosity of the open hackers communities in New Zealand.