Green Buildings -part 2

An Icelandic house with a living roof

Biomass

Biomass can be used for heating buildings and generating steam to make electricity. A wood (or biomass pellet) stove is perhaps the most obvious biomass heat source in most homes and modern versions have minimal particulate pollution. Larger biomass plants burn gases extracted from heating wood chips, straw, manure or municipal solid waste. Garbage dumps are an ideal source of biomass gas when the methane from decomposing matter is recovered and burnt rather than released as a greenhouse gas that is 30 times more damaging than CO₂. Often biomass plants are located next to readily available biomass sources such as a lumber processing company.

Dependent upon location, a typical North American household roof captures almost 100,000 litres or water per year.

Geothermal Heat Pumps (GHT)

GHTs are a great way to reduce heating and air conditioning costs to around a dollar a day and eliminate, on average, 50% of the greenhouse gas emissions compared to traditional fossil fuel use. In the summer the building is cooled as the GHT pumps heat into the ground (or water) via a heat exchanger. In winter GHTs reverse the process to heat the building’s hot water and/or heating system.

Green (or Living) Roofs

You can use Mother Nature’s natural gifts by growing grass or other plant matter on your roof or walls. With layerings of growing mediums, filters, insulation and structural support, it is possible to have 4 inches (10cms) or more of soil, grass and plant material to insulate your home against heat loss in the winter and help cool it in the summer with savings of upwards of 25%. Living roofs are very popular in Germany, France, Iceland and Switzerland. Benefits of living roofs include the ability to grow food & flowers, provide habitat for birds and insects, insulate against noise and electromagnetic emissions and have a carbon neutral roof.

Living Walls

Living walls, biowalls or living buildings operate as filter systems that take volatile organic compounds (VOCs) and CO₂ from the air while naturally purifying the indoor air quality. Living walls also conserve energy by encouraging cooling in the hotter months and providing additional insulation in the warmer months. Increasingly, living walls are being used to filter stormwater or grey water, directly contributing to a reduction in water pollution and stormwater drain outflow. Living walls are also aesthetically pleasing and operate as a soothing natural backdrop to any public or private space.

Grey Water

A grey water system, comprised of a simple filter, storage and plumbing system, can capture your bath, shower and laundry water to be re-used in your toilets and/or garden after filtering and adding some natural chlorine. It is possible to save up to 30% on water bills and reduce the stress on reservoirs and sewage systems by filtering your grey water for reuse.

Hypo-Allergenic

Most modern buildings are designed to minimize heat loss and do so by limiting the air exchange between the inside and outside. Unfortunately, when many paints, cleaning products and even everyday objects such as televisions, furniture, carpets and other household items off-gas volatile components, it means indoor air quality is often much more polluted than the air outside, even in a city centre.

The building construction process is often full of products that off-gas; including treated wood, chipboard, adhesives, silicone sealants, cements, dry walling and insulation materials. It is no wonder ‘sick building syndrome’ and ‘chemical sensitivities’ are such widespread illnesses in modern buildings. Green builders substitute chemical products with more natural products that are better for the environment and health. Rammed earth, strawbale and ecological homes tend to be much more hypoallergenic than traditional structures.

Off The Grid

How about having no household heating, lighting and water bills? Well, having your home ‘off the grid’ does just that, with no connection to public electricity, gas, water or sewage. Almost 2 billion people live ‘off the grid’ maybe more by circumstance than choice in many countries, but it is becoming more popular every year in developed nations. Whether it is to avoid paying connection and usage charges, or to minimize one’s global footprint, increasingly green builders are opting to construct or retrofit homes with independent renewable energy supplies, low heat loss insulation, rain catchment and septic systems.

Rain Catchment

In many countries, such as New Zealand, India, Australia and Canada, people capture rainwater for potable uses, especially in more arid or isolated areas. This system of obtaining safe drinking water is becoming popular in many countries as reservoirs and aquifers are put under more stress and drought conditions are becoming more commonplace due to over-consumption of water resources and global climate changes. In countries reliant on glacial melt run off to supply dams, future drinking water may have to come from rainwater capture as the glaciers disappear. Careful choice of roof material, gutter design, initial water bypass and filtration system are needed to ensure safe, potable water. Dependent upon location, a typical North American household roof captures almost 100,000 litres or water per year.