Several buildings across the world have achieved net-zero or positive-energy status. But not as many retrofitted buildings have deployed similar green building measures to become truely passive structures. That’s why a group of students and researches at Harvard University are currently renovating a building on Harvard’s campus as a prototype for ultra-efficient retrofits.

哈佛大学设计研究生院（GSD）的哈佛大学绿色建筑和城市中心（CGBC）正在使用自己的建筑物作为原型，他们称为HouseZero项目。改造完成后，1940年代之前的棒状房屋将不具有HVAC系统，或者在白天需要使用电灯。它将达到100％通风，产生几乎零的能量并产生零碳排放，包括材料的具体能量。

Thermal mass and a ground source heat pump will replace the HVAC system, a solar vent will “instigate buoyancy-driven ventilation and triple-glazed windows will employ natural cross ventilation through a manual and automated system that monitors for temperature, humidity and air quality,” according to a press release about the project.

设计学院建筑技术教授，绿色建筑和城市中心的创始主任Ali Malkawi说，这些系统通常仅在新建筑中使用。Malkawi在新闻稿中说：“我们想展示什么可能，显示如何在任何地方复制它，并解决世界上最大的能源问题之一 - 现有的建筑物。”

Snøhetta is serving as lead architect for the project as well as the interior and landscape architect. Skanska Technology created the energy concept along with CGBC research teams. Skanska USA performed preconstruction work while Columbia Construction will manage a construction period that could last as much as nine months.

Designing the building envelope in layers, along with a series of technologies, will allow the building to adjust to optimal interior climates. “All components of the building are sensored to generate data that will allow the building to adjust itself and fuel CGBC research focused on actual data and simulated environments,” Malkawi says.

The building itself will also double as a laboratory to help develop technologies, façades, and materials for other ultra-efficient buildings. The “flexible, highly-controlled and monitored experimental lab” will be connected to the building’s energy exchange system.

HouseZerowill not seek certification rating from the US Green Building Council’s Leadership in Energy and Environmental Design or the Living Building Challenge because, as the press release notes, “it wants to demonstrate an entirely new paradigm for ultra-efficiency, one that is localized and focused on curbing energy demand, with energy production secondary to that.”

Mohsen Mostafavi, Dean of Harvard Graduate School of Design, says in the press release, “The HouseZero project represents precisely the kind of transformative impact through design that we strive to make at the GSD. With this test case–retrofitting a house in Cambridge into a new work space–the Center for Green Buildings and Cities directly engages the ways in which we can reimagine the future of many of our cities and their utilization of resources.”