With 23% of carbon dioxide emissions generated by the heating and cooling of residential buildings in the United States, smart choices of technologies that maintain indoor air quality and create a comfortable environment could significantly reduce the greenhouse gases that contribute to climate change.

In 2007, when I was CEO of Kingspan Century in Ireland, we developed and launched Europe’s first net-zero energy home, which we named “Lighthouse,” through innovative uses of available technologies combined with integral design considerations.

Constructed for lifestyles that are inherently “light” on the world’s resources, Lighthouse was unveiled at the Building Research Establishment, Britain’s biennial showcase for sustainable buildings, and was the only structure that met the “Level 6” building standard – the highest level – of the Code for Sustainable Homes, which the British government aims to achieve by 2016.

To minimize the energy required to heat and cool Lighthouse and achieve carbon neutrality, we set out to reduce the structure’s heat loss, while incorporating daylighting strategies as well as mechanical and renewable energy systems to address seasonal needs.

The two-story, two-bedroom Lighthouse was constructed with sustainable materials in a six- week period using Kingspan Off-Site’s TEK building system, a high-performance structural insulated panel based system.

The use of this technology, coupled with the state-of-the-art design of the building envelope, helped to create a high level of thermal insulation and performance in the airtight structure in order to reduce heat loss by potentially two-thirds of a standard house. The estimated annual cost to heat Lighthouse – in the temperate maritime climate of the United Kingdom – is approximately $80, given that the home only needs to be heated for a couple months during winter.

A biomass boiler that uses wood pellets provides the heating function. The boiler, which also heats the water in the winter, is located in the utility room on the ground floor. This placement provides another energy-saving benefit: the occupant has a dedicated area in which clothes can be hung to dry as an alternative to using an energy-sapping clothes dryer.

Dependence on the biomass boiler for heating, as well as the amount of wood used, are both minimized by the solar thermal panels placed on Lighthouse’s dramatic sloping roof. These panels provide all hot water in the summer and some in spring and fall.

The layout of the house was turned upside down from conventional homes to maximize the use of daylighting and passive solar heating. The living areas were placed upstairs for natural light and enhanced natural ventilation. The bedrooms, which require less daylight, were located on the first floor.

Because of the focus on the building’s insulation, the placement of each triple-glazed, gas-filled window had to be carefully considered in order to maximize lighting and ventilation while minimizing the number of windows installed.

An electrical whole-house ventilation system with heat recovery provides the background ventilation in the home – particularly during the winter months, when it extracts heat from warm stale air to heat incoming cool fresh air. This system is powered by photovoltaic panels.

For energy efficiency during the summer, the mechanical system is complemented with a passive natural ventilation system that employs a “windcatcher” on the chimney. When open, the device admits cooler outside air to displace warmer inside air and can be used in conjunction with operable windows for enhanced cross ventilation.

The windcatcher, which provides secure ventilation at night, also functions as a “light funnel” to illuminate both floors of the house with natural lighting during the day.

Adjusting both the passive ventilation devices and the shading on windows allows the occupant to create the desired indoor environment in terms of both thermal and luminous comfort as the outdoor temperature rises.

Other considerations to lower the indoor temperatures during the warmer summer months included the installation of low-energy appliances, which are also low-heat emitting, and the use of “thermal heavyweight” ceiling surfaces.

These ceiling surfaces, which include phase change material (PCM) plasterboard, absorb the heat in the house and provide natural cooling when the microscopic capsules embedded in the board change from solid to liquid. At night, the process is reversed to extract the heat absorbed with the help of the windcatcher.

The house also has a smart metering system to record energy consumption and help the homeowner identify areas in which consumption could be reduced.

With Lighthouse, U.S. builders have a prototype for eco-friendly heating and cooling technologies that have been successfully used, and can easily be replicated in markets with similar climate and site conditions. Many of the technologies utilized in Lighthouse are over-specified for warm-weather U.S. markets, such as Southern California, a region that is primed with many environmentally conscious consumers who have already embraced the concept of sustainable living.