Green Building Materials and Techniques

Green building

• Focuses on increasing the efficiency of resource use –energy, water and materials.

• While reducing impacts on human health • And environment during the Lifecycle, through better

siting, design construction and operation.

Emphasis on:• Reduced energy use – Efficient and

alternative sources which are less polluting

• Reduced waste- Reutilising our industrial and agricultural wastes

• “ The Environmental impact of building is often underestimated, while the perceived costs of green buildings are overestimated”

Why eco-friendly materials?

• Phenomenal growth in the construction industry that depends upon depletable resources.

• Production of building materials leads to irreversible environmental impacts.

What is Eco-friendly material ?

• Dictionary: describes a product that has been designed to do the least possible damage to the environment

• US EPA – EPP program defines as: “ products or services that have a lesser or reduced effect on human health and the environment when compared with competing products or services that serve the same purpose...”

SOURCES

A) Renewable source – Rapidly renewable sources e.g. wood from certified forests

B) Reuse of Waste - Salvaged products –e.g. old plumbing, door frames

C) Recycled contents – agriculture/ industrial waste e.g. Firbreboard Board

Reclaimed materials• Construction materials account for:

• 420 million tonnes of material consumption (7 tonnes per person)

• 20% of the UK’s total ecological footprint

• 19% of the UK’s total greenhouse gas emissions

• 30% of all UK road freight

UK’s total greenhouse gas emissions

Greenspec ® Reclaimed Materials Article - http://www.greenspec.co.uk/reclaimed-materials.php

Why Use Reclaimed Materials

• Substitution of reclaimed materials for new will radically reduce the environmental impact of that particular item.

• It removes the need to extract more raw materials and it largely removes the need for processing and manufacture.

• Transportation impacts are usually reduced too as reclaimed materials tend to be sourced locally (although not always). 

BRE life cycle analyses comparing new with reclaimed

Greenspec ® Reclaimed Materials Article - http://www.greenspec.co.uk/reclaimed-materials.php

Greenspec ® Reclaimed Materials Article - http://www.greenspec.co.uk/reclaimed-materials.php

Potential for reclaimed

• Waste from construction and demolition produces a massive, virtually untapped, sustainable resource. Salvo estimate that only 1% of building materials are currently from reclaimed sources. Whereas some 5-10% of the building materials demand could potentially be met from reclaimed. (Salvo, A Reclamation Protocol, 1995). 

 Diverting and re-using salvaged materials from the waste stream maintains them as a high grade resource instead of down grading them by crushing or chipping.

Embodied Energy

• Total energy input required to produce the product including transporting them to the building site .

• Aluminum and steel has the most embodied energy because to the high energy required to produce them. Compared to timber that requires very less energy for production.

This shows relative carbon emissions for three common building materials. Please note that emissions data are based on metric tons (1000 Kg) of each material.

Reduce Pollution

• Air Pollution - Use of materials with low VOC emissions e.g. Cement Paints

• Water Pollution – Materials that prevent leaching.

• Land Pollution - Materials that reuse waste that would otherwise have resulted in landfill e.g. Fly ash Bricks .

Energy Conservation

• Materials that require less energy during construction e.g. precast slabs . Materials that help reduce the cooling loads- e.g – aerated concrete blocks.

• Products that conserve energy – e. g. CF lamps. (compact fluorescent lamps)

• Fixtures & equipments that help conserve water e.g. Dual flush

cisterns

Performance

• Materials can be eco-friendly based on how they perform. Use of certain material or techniques can reduce the amount of material required.

• Durability – The longer the life of a material the lesser it is required to replace and thus reduces the quantity required to produce.

Advantages of GREEN Buildings vs. Conventional Buildings

• Cost Savings (Ongoing Operating Expense Reductions)

• Minimize Impact on Environment • Enhanced Health & Productivity of

Occupants • Increased Value & Lease-Up Rates • Community & Social Benefits • Other Owner Benefits (Lender Incentives;

Tax Abatements; Etc.)

Myths Surrounding Green Buildings

• They are too complicated • “We're not already building green!”• Over hyping benefits and performance • Cost Perceptions • Too expensive and has no ROI • Initial costs not recaptured in long term • Costs too high to warrant

Myths Surrounding Green Buildings Performance Expectations

• Green automatically reduce expenses • It costs less to build and maintain • More green, more operating problems

LIMITATIONS OF GREEN BUILDING

• Initial Cost- Some materials costs are higher

• Funding –Some lenders will not offer loan • Availability of materials• Location • Time frame needed – Materials take more

time

Nanotechnologies and Green Buildings

• A study commissioned by the nanotechnology group of the UK's Department for Environment Food and Rural Affairs (Defra) looked into the policy implications of nanotechnologies that will benefit the environment.

• Five nanotechnology applications were subject to detailed investigation: fuel additives, solar cells, the hydrogen economy, batteries and insulation.

Fuel additives

• Nanoparticle additives increase the fuel efficiency of diesel engines by approximately 5% which could result in a maximum saving of 2-3 millions of tonnes (Mte) per annum of CO2 in the UK.

• Concerns about the health impact of free nanoparticles in diesel exhaust gases.

Solar cells

• Nanotechnology may deliver benefits in significantly decreasing the cost of production of solar cells.

• Conservatively, if a distributed solar generation grid met 1% of the UK's electricity demand, approximately 1.5 Mte per annum of CO2 could be saved.

• The major barrier to this technology is the incorporation of the nanotechnology into the solar cell, not the nanotechnology itself. Lack of skills to transfer the science base into workable prototypes.

Batteries and Supercapacitors

• Nanotechnology may provide a remedy to the charge time problem by allowing electric vehicles to be recharged in much more quickly.

• If low carbon electricity generation techniques are used, CO2 from private transport could be eliminated (resulting in a maximum potential saving of 64 Mte per annum) or, using the current energy mix, maximum savings of 42 Mte per annum of carbon dioxide could be made.

• Without nanotechnology, electric vehicles are likely to remain a niche market due to the issues of charge time

Insulation • No easy methods for insulating solid walled buildings, which

currently make up approximately one third of the UK’s housing stock.

• Nanotechnology may provide a solution which, if an effective insulation could be found with similar properties to standard cavity insulation, could result in emission reductions equivalent to a maxim potential of 3 Mte per year.

• Ultra thin films on windows to reduce heat loss already exist on the market. There are claims that nano-enabled windows are up to twice as efficient as required by current building standards.

• However, industry believes that significant further insulative savings in glass maybe made instead using aerogels, which themselves are nanostructures.

ISSE Green Products

• The ISSE is evaluating and commissioning research via nanotechnology and reclaimed materials technologies for a solution to the increasing level of environmental damage caused by the construction industry

• As the information and concept is commercially sensitive no information can be provided here.

• http://www.nanowerk.com/spotlight/spotid=2225.php

• http://www.greenspec.co.uk/reclaimed-materials.php