Indoor air routinely carries two to five times the pollutant load found outdoors, and in poorly ventilated homes the ratio can reach 100 times higher. The EPA classifies indoor air pollution among the top environmental health risks in the United States, linking it to heart disease, cancer, allergic reactions, pneumonia, asthma, and low birth weight. […]
Concrete dominates modern construction, yet a growing number of builders are asking whether hempcrete can take over part of its workload. Hempcrete is a bio-composite made from the inner wood core of the hemp plant, mixed with lime and other natural materials, while concrete is a blend of cement, aggregates, and water. The two materials
Hempcrete is a bio-composite building material made from the inner woody core of the hemp plant, mixed with lime and other natural materials. Also known as hemp-concrete, it has moved from experimental walls to mainstream low-carbon construction because it is lightweight, breathable, and easy to work with. Builders use it to construct, renovate, and restore
Polystyrene foam sits behind more foundation walls and under more concrete slabs than any other rigid insulation in North America. Designers reach for it because it insulates well, shrugs off moisture, carries building loads, and costs less than most rigid boards. The same material now faces hard questions from the green building community. A flame
Most people accept that buildings and the process of development carry a large environmental cost. The exact size of that cost is harder to pin down, because different sources report different figures and the numbers shift as the building stock, the grid, and the economy change. Accurate statistics matter because they make the case for
Structural materials get more environmental scrutiny than almost anything else in a building. Cement production releases large volumes of carbon dioxide, steel carries high embodied energy, and wood raises questions about forestry and land use. Manufacturers answer with different strategies: recycled content, alternative fuels, certified fiber, and carbon offsets. Because every material has a complicated
Buildings are far more complex than the structures of a few decades ago. Sophisticated systems control comfort, lighting, vertical transport, security, and fire safety, and each one is designed and installed by a specialist who may understand its own behavior but not how it interacts with the rest of the building. Tight budgets and liability
Sprawl pushes development onto farmland, open space, and woodlands, and one of the strongest counters is to build where the ground was already used. That usually means a brownfield: an abandoned, idled, or under-used industrial or commercial site where redevelopment is complicated by real or perceived contamination. The obstacles are real, from toxic heavy metals
Insulation is one of the most effective carbon-reduction measures available to builders, yet the material chosen can quietly undo part of that benefit. Extruded polystyrene (XPS) board and standard closed-cell spray polyurethane foam are manufactured with hydrofluorocarbon (HFC) blowing agents, gases that trap thousands of times more heat than carbon dioxide. Every insulation material reduces
Some of the most valuable efficiency features in a green building hide below grade. One Bryant Park, the 2.1 million square foot (195,000 square meter) office tower in New York City that pursued LEED Platinum, drew attention for its rainwater harvesting, onsite wastewater treatment, optimized daylighting, and combined heat and power plant. The feature that
