Can a Passivhaus Building Be Economically Viable in the US?
When it comes to the economic feasibility and technical viability of Passivhaus buildings in the United States, several factors come into play. Initially developed in Europe, Passivhaus design focuses on significantly reducing the energy required for space heating, which traditionally necessitates a longer heating season with higher energy costs.
Prerequisites for Passivhaus Success
For Passivhaus to work both economically and effectively, a reasonably long heating season is essential, along with prevailing energy prices that incentivize energy efficiency. Traditionally, Passivhaus has gained popularity in the middle and northern regions of Europe, where the ‘winter’ season typically extends from October to April. Given these conditions, it is less certain whether Passivhaus would perform as well in the milder climate of the US.
However, there is a good chance that the same principles and methodologies utilized in Europe could also yield effective results in the US, particularly in the mid- and northern states. A Passivhaus building, whether a schoolhouse or another structure, would typically cost about 20% more than conventional construction due to the absence of a heating system, such as a boiler, distribution pipe work, pumps, controls, radiators, or underfloor systems. On the other hand, it would incorporate enhanced insulation (400mm wall thickness is typical), MVHR (mechanical ventilation with heat recovery), and A-rated white goods, like a fridge freezer, washing machine, and dishwasher, which are generally more costly.
Energy Savings and Cost Benefits
The core criterion for a Passivhaus building is its maximum heating energy requirement of 15 kWh/m2. This is roughly 70% less than the energy required by buildings that comply with standard building regulations, and approximately 90% less than much of the existing building stock. In the UK, for instance, over 60% of a domestic building's total energy use is for heating, while about 90% of a building's total lifecycle energy usage (from cradle to grave) is attributed to its operation.
Given these figures, the savings potential is substantial. The energy saved by a Passivhaus building can be translated into significant reductions in carbon emissions and running costs. Even with relatively cheap gas in the US, costing around 3p per kWh, the amount of energy saved by a Passivhaus building can lead to a payback period of approximately 10 years.
Conclusion: Financial Viability is Key
While Passivhaus buildings offer a robust solution for energy efficiency, their success is not guaranteed without careful consideration of the specific environmental and economic conditions.
It is not the only passive and low-energy building solution, and design needs to be tailored to the specific environment. Incorporating high levels of thermal mass and ground-coupled air systems might provide similar or greater savings in predominantly cooled buildings in your climatic zone. At the end of the day, if a Passivhaus building is not economically incentivized, it will not be economically viable. Cheap and abundant fossil fuels are wasteful, neglectful, and ignorant of a range of issues facing humanity.