Waste Management

We generate vast amounts of waste in ordinary living, and most home designs do little to minimize, mitigate or manage this waste. Let's consider a few examples:

Human bodily waste is perhaps the most egregious case. Modern homes either connect to a public sewage system, or have a private septic system. Both utilize considerable amounts of an increasingly scarce and precious resource - fresh water - to transport waste, resulting in huge amounts of contaminated water to deal with along with the original waste, multiplying the waste volume dramatically. Since the reactive house is autonomous, it cannot connect to public sewage; should it rely on a septic system?

Septic systems have many negatives beyond reliance on water for waste transport. First, extensive excavation and other site disturbance is required for settling tanks, leaching fields etc (some codes require an area equal to the leaching field to be cleared for when the first fails). Both the embodied energy of this system and the ecological damage to the environment are non-trivial. Nor does it end there: since typical systems need to be pumped out periodically, access via a driveway or other passage capable of supporting heavy trucks must be constructed and maintained. In addition, failed septics are common and contaminate streams, rivers, and other wetlands. The total footprint of these systems are massive, and should be completely avoided.

The reactive house will eschew traditional septic designs and treat human waste in safer, less resource-intensive ways. This will undoubtedly be a challenge, since current technology (composting, incinerating, freezing, 'Gates' chemical toilets, etc) does not offer easy or compromise-free solutions. Nonetheless, we cannot continue with the intolerable status quo and pretend to be sustainable; fortunately, this is an area of active innovation and research.

Another large issue is thermal waste: conditioned air, DHW, chimney flue losses, etc. are in energy terms perhaps the greatest sin committed by modern homes. Here, however, unlike the sewage case, there are many well-established, practical and cost-effective solutions available. Start with Passivhaus-level insulation, attention to thermal bridging, and air sealing to reduce thermal loss through the envelope. Next, use HRV/ERV units to capture thermal energy escaping with stale air. Possibly also leverage drain water heat recovery systems for DHW losses. There is a large solution space here, and the main imperative is to do rigorous cost/benefit analyses to ensure that dollars are spent for maximum results.

One generally underappreciated waste management issue is organic kitchen waste: it is typically dealt with a lot like bodily waste: using a lot of precious water in a garbage disposal to flush to the public sewer. Home composting can help considerably, but in many climates, it is difficult to practice. For example, in cold climates, outdoor composters can be difficult to reach and use (since they are frozen). Or in hot climates, decomposition occurs quickly enough that keeping ahead of it can be laborious. The reactive house will attempt to eliminate, or at least radically reduce, organic waste. There are promising new approaches, e.g. rapid indoor composting or vermiculture.