Sustainable Building Design

Sustainable building design incorporates design elements, materials, construction methods and energy efficient technologies into a building environment. It considers environments both inside and outside the home, and the activities to be performed by the homes inhabitants.

To ensure a building meets the guidelines of sustainability, a designer must ensure that wherever possible, resources used in the construction are made from renewable resources, rather than those limited in worldwide supply. This includes materials utilizing fossil fuels used to create gas and electricity, and ensuring that any emissions from the building are minimised, aiming for a low or non-carbon contribution.

Sustainability of any home considers:

• Location
• Space Utilisation
• Materials
• Construction
• Insulation
• Lighting
• Water Management
• Waste Management

Many of these sustainable systems are combined in tandem with modern technology to provide a hybrid home environment.

Location

Location refers to both geographic regional and seasonal environmental factors as well as sun and noise exposure.

The most sustainable supporting locations:

• Have a good aspect to capture all day sun
• Are surrounded by deciduous vegetation - to provide shade in summer and sun in winter. Vegetation also filters the air and helps create a noise barrier.
• Have amenities nearby - a safe 10 minute walk to transport systems. shopping, parks, schools, to reduce the reliance on transportation
• Are not close to industrial areas or major transport routes - where hazards of noise and toxic pollution are higher

Spatial Design

Sustainable design of spaces ensures that activities are supported in the most natural environment within the building envelope. Activities that require heat are separated from those requiring cooling and integrated into the use of renewable resources, such as bio-fuel or solar power. This ensures the buidling is planned in an environmentally and energy-efficient way. Even small elements, such as placement of the refrigerator on a cool wall in the kitchen contribute to the overall energy efficiency.

In the design plan, consideration is given to both internal and external space. Energy efficiency is not the only factor, with health impact on the inhabitants playing the major role in sustainable design. Studies have shown that ventilation and air circulation affect buildings users, hence how will air be refreshed and cleansed is a critical element. Extraction of any toxic fumes resulting from activities is also paramount.

A well designed sustainable home appears spacious, open plan, and energised, providing maximum health sustenance for its users. Consideration is given to:

• Space requirements for activities performed within the home
• Aggregation of activities that require similar environments and/or have similar outputs of noise, odors, heat, cooling, etc
• Egress to and from each space to support the free flow of people and objects
• Division and privacy - both physical and audible
• Storage and amenities

Aesthetics also play a role in sustainable design. The Japanese are masters of eco-friendly spatial design, with every element of the interior and exterior contributing to the physical, mental and spiritual well being of its inhabitants. Concepts such as Feng Shui ensure that a building harnesses the best from its environment, and voids and negative elements.

Materials

The materials used in a home contribute not only to its contribution to energy sustainability, but also to the ecology.

Timber - a very durable, sustainable resource often wasted in construction. wasted. In the UK, an estimated 2.5 million tonnes of wood is wasted from construction each year, being either burnt or put in landfills. This wastage is largely driven by the relatively low cost of timber. The ecological impact of devastation of forests is largely ignored in many regions. Forests act as carbon sinks - they take more CO2 from the atmosphere than they give back. Timber used in construction stores that carbon ttypically 28.5 tonnes in a 215 sq. m wood-fame house]. Reducing wasteage, reduces the extraction rate from the forests, giving them a greater chance to regenerate.

Insulation - there are many different types of sustainable insulation.

• Natural wool
• Rockwool - steel slag heated together with volcanic rock at high temperatures
• Cellulose - from recycled newspapers. Note: printer's ink can leak formaldehyde.
• Agricultural fibre - available in batts treated with a non-toxic fire retardant
• Isonet - a mix of hemp fibres and recycled cotton, with a favourable u-value.
• Cementitious foam - a natural product made from magnesium extracted from sea water. The foam product is blown into wall spaces.

Energy-Efficient Materials

Material energy efficiency derives from either its inherent properties, and/or its recycling elements. For instance, the following materials are often incorporated into sustainable design:

• Materials produced in harmony with the environment
• Recycled flooring and gypsum wall boards
• Ecologically-friendly finishing and cleaning materials
• Energy efficient light bulbs and appliances
• A green 'living' roof - a turf-based garden upon the roof

Construction Methods

Advanced Framing - sustainable building methodologies include "advanced framing", where unnecessary framing elements are omitted, and sizing of structures are minimised. Smarter design ensures that windows and doors are are properly aligned with the frame, avoiding additional framing elements.

Waste Recovery - recovery of waste wood is improving. Generally, only around 35% of demolition wood is reusable. Improved methods of deconstruction are increasing this percentage.

Lighting

Light access and control is a major element of design. Where possible, natural light is the only or main source of lighting. Natural lighting has also proven beneficial to human productivity - both in terms of physical benefits and also in mental benefits gained from feeling more connected to our external surroundings.

More on sustainable lighting.

Insulation & Heating

Ambient temperature control is an integrated design element of any buidling. It considers not only the temperature, but also the intrusion element of any heating appliance, and any adverse health impacts of the heating method. Typical heating examples include:

• Under floor heating & cooling system - although when used with carpeted rooms, underfloor heating does increase the irritation to those with breathing difficulties.
• Radiators and heat pumps - can be intrusive and space-consuming
• Solar heating systems - should definitely be considered, either alone or in combination with other heating technologies.
• Wood burning fire places and boxes - are more difficult to control in temperature and emit toxins from the wood to both the internal and external air.

More on sustainable heating.

There are many elements of sustainable design that can be incorporated not only into new construction, but also in remodeling and renovations.

Next: Energy Efficient Appliances

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