Green building was developed in the 1970s, during the energy crisis, when people finally realised that they needed to save energy and alleviate environmental problems.
The idea originated on the United States, as they were one of the largest contributors of pollution in the world.
Due to the fact that Buildings account for a large amount of land, energy and water consumption, and also contribute hugely to air pollution, green building aims to reduce the environmental impact buildings have on the environment.
Practices and technologies used in green building are constantly improving. Many are different from region to region, however there are fundamental principles that must be followed.
Green building is an outcome of a design philosophy, which focuses on increasing the efficiency of 4 main resources:
Along with increasing efficiency, green buildings also aim to reduce the impact buildings have on human health and the environment during the building’s lifecycle.
This is achieved by improved design, construction, operation, maintenance, and removal of waste materials.
It is generally agreed that green buildings are structures that are sited, designed, built, renovated and operated to energy-efficient guidelines, and that they will have a positive environmental, economic and social impact over their life cycle. Green specifications provide a good set of guidelines for the building industry, but these are still in the process of being formalised into UK regulation and many are open to interpretation.”
Green building requires a holistic approach that looks at each component of a building and how it relates in context with the whole building. This allows us to look at the impact the building will have on the wider environment and community around it.
Green Building is a difficult approach, which needs builders, architects and engineers to think creatively, and increase the level of integration throughout the project.
There are several resources and published guides that can help builders with the green building process, such as BREEAM (Building and Research Establishment Environmental Assessment Method), the Code for Sustainable Homes, and EcoHomes.
“Green Building is not simply about protecting the biosphere and natural resources from over-exploitation or over-consumption, nor is it simply about saving energy to reduce our heating bills. It considers the impact of buildings and materials on occupants and the impact of our lives on the future environment.”
(Source – Tom Woolley, Sam Kimmins, Paul Harrison and Rob Harrison 1997. Green Building Handbook. Oxford: Spon Press . 5.)
Green Building Essentials
There are four main criteria that need to be considered in green building.
The materials used in Green Building projects need to be:
- From a natural, renewable source that has been managed and harvested in a sustainable way.
- Obtained locally in order to reduce the embedded energy costs of transportation.
- Sourced from reclaimed materials at nearby sites.
Materials are graded using green specifications which look at their life cycle and analyse them in terms of their embodied energy, durability, recycled content, waste minimisation, and their ability to be reused or recycled.
Some examples of building materials that are considered ‘green’ include:
- Renewable plant materials such as straw.
- Timber from sustainably managed forests.
- Recycled stone
- Recycled metal.
- Products that are non-toxic, reusable, renewable, and/or recyclable eg. linoleum, sheep wool, compressed earth blocks, rammed earth, clay, flax linen, cork, sand stone, and concrete.
Building materials should be sourced and manufactured locally to the building site where possible in order to minimise the energy used through transportation.
It is also desireable for building elements to be manufactured off-site, then delivered when needed. The benefits of this include minimising waste and maximising recycling as manufacturing is in a set location.
Energy consumption is a major issue, which green building principles aim to address.
Nearly all UK houses are extremely inefficient when it comes to heating and lighting consumption.
One method of reducing heating and ventilation costs for a building is to incorporate Passive Solar Design. This is when the suns energy is used for heating and cooling various living spaces. These passive systems are extremely simple in design, having very few moving parts and usually require no mechanical systems therefore they have a minimal maintenance issue.
Common features of passive solar heating include windows that can be opened and closed. Passive solar design incorporates the use of thermal mass also. This is when materials such as masonry, concrete and water actually store heat for a period of time this can prevent rapid fluctuations in temperature.
High levels of insulation and energy-efficient windows can help to conserve a lot of energy from escaping through the buildings envelope.
In regards to lighting a building, natural daylight design reduces the need for electricity in a building while improving the occupants health and productivity.
Green buildings also incorporate energy-efficient lighting, low energy appliances, and renewable energy technologies such as wind turbines and solar panels.
Reducing water consumption in a ‘Green’ House is an important aspect in many of the green building rating systems. It is therefore essential that water can be recycled around the house. This can be achieved by installing greywater and rainwater harvesting systems which will re-use water for tasks like watering plants or toilet flushing. Incorporating water-efficient appliances in kitchens and bathrooms, such as low flow showerheads, self-closing or spray taps, low-flush toilets, or waterless composting toilets, will all aid in reducing the amount of water required for the day to day running of the house.
This aspect of Green Building refers to the health of the buildings occupants.
Using non-toxic materials in construction will help to improve indoor air quality, which can reduce the rate of respiratory illnesses such as asthma. The materials and products used in a green design need to be emission-free and have very little or no VOC (Volatile organic compound) content. They also need to be moisture resistant in order to prevent moulds, spores from growing inside the house.
Indoor air quality can be improved through ventilation systems and using materials in the construction of the house that control humidity and allow a building to breathe.
A major factor which isnt included in the main four topics I have discussed above is what happens after the construction of the building has been completed.
It wont matter how sustainable the design and construction stage of the project was if the building is not maintained responsibly. This needs to be considered at the planning stage of construction and the occupant must be briefed on the green building concept. They should also be informed that in order to keep the ‘green’ status the building will have, careful and considerate maintenance methods will need to be employed, with the possibility of the need to upgrade aspects of the building to keep up to date with changing regulations and standards.
It is also important that the occupier continues green practices such as recycling throughout the life-cycle of the building.
A green building should provide cost savings to both the builder and occupant. It should also benefit the community through the use of local labour.
Advantages and Disadvantages of Green Building
I am going to first outline some of the disadvantages of green building, as most people tend to focus only on the positive aspects. Considerations such as cost, funding, material availability and location restrictions must be taken into account when planning a green build project.
One of the most common disadvantages of Green Building is the additional cost incurred. This is due to the increase in the quality of construction methods and materials used. Although energy savings can balance the extra costs out, it is still seen as a disadvantage the fact that extra money needs to be spent at the construction stage.
Eco-friendly building materials are often difficult to find in many areas of the UK, which can lead to prices being much higher than standard building materials. While projects close to larger cities may have no difficulty finding green building materials, suppliers may be scarce in other areas.
Many materials require special ordering, which could increase costs. Some other materials may only be available through Internet orders, which will increase the cost due to shipping and handling. The green building market is becoming much more competitive due to the increase in demand for this type of construction, and Green Building costs are predicted to decrease in the near future.
Apart from the initial cost of green building, finding a mortgage company or bank that offers loans for a building that is not built in the traditional way may be difficult.
The time taken to complete a green building can also be viewed as a disadvantage. Green building projects encourage the use of recycled materials and trying to source these can add to the time to complete a certain stage of the build that the contractor and client haven’t allowed for in the project.
One overlooked disadvantage is the fact that in recent years houses have become more airtight, which has added to the problem of indoor air quality. Houses have become so sealed that there is now an increase in indoor pollution.
An example of how this can occur is if a builder decides to use some recycled material but is unaware of any chemicals that may be contained in it. The chemicals may give off volatile organic compounds, which have in fact been found toxic to humans.
Most green building guides have a section on Indoor Air Quality, ventilation, filtration systems, and suggestions for low or no VOC products in the building process to address this issue.
The benefits of green building are what most people want to know nowadays, and below are some of these advantages. They have been categorised into three main areas, Environmental, Economic and Social Benefits.
Reduction of Emissions:
Using green building techniques such as solar power and daylighting increase the energy efficiency of the building, and also cut down harmful emissions released by fossil fuels. This can help reduce air quality issues such as smog and acid rain.
Conservation of Water:
Significant water savings can be created by introducing methods such as rainwater and greywater harvesting. These methods use and recycle various water sources, which can then be used for irrigation in gardening and for flushing toilets. Stormwater management can also be helpful to the environment by reducing localised flooding, which can carry pollution into water sources, and erosion. Rainwater harvesting and using building materials that are permeable for driveways can help reduce this risk.
Green building promotes increased efficiency both during and after the construction phase. Recycling and reusing waste materials will lead to a decrease in the amount of waste that needs to be dumped in landfills.
As I mentioned above, some people believe green building to be too expensive. Previous studies have shown that costs are not substantially higher than traditional developments.
As long as the designer and client have decided to go down the route of green building, the high construction costs can usually be avoided.
Although the costs may be higher at the beginning of a projects life cycle, they can be recouped throughout the life of the building.
Due to the increased efficiency from green design and new technology, operation costs from heating, electricity and water can all be reduced dramatically, resulting in a low payback time on the money invested at the beginning of the project.
Green buildings can also be sold or rented quicker, and at a premium rate because of the low maintenance and utility bills. This will prove to be a unique selling point if the cost of fuel continues to rise.
Another very impressive advantage of a green building is its ability to improve the occupier’s health. Conditions such as respiratory problems, skin rashes, nausea and allergies, which can result from insufficient air circulation, poor lighting, mould, toxic adhesives and paints, can be significantly reduced in a green built house. This is because green building emphasises the need for proper ventilation and the reduction in use of toxic material, which will create a healthier living environment.
Another key element of green building is the need to preserve the natural environment. This can provide a variety of recreation and exercise opportunities. Green buildings also seek to facilitate alternatives to driving, such as bicycling by awarding points for providing bike docks (In the Code for Sustainable Homes), which eases local traffic while increasing personal health and fitness.
Summary of Advantages and Disadvantages of Green Building
Below are the disadvantages and advantages summarised in point form.
- Initial cost.
- Funding for projects from banks hard to get.
- Location Factor.
- Availability of Materials.
- Implications on air quality due to the use of some recycled materials.
- Environmental Benefits.
- Reduction of Emissions.
- Conservation of Water.
- Reduced localised flooding.
- Waste reduction.
- Economic benefits.
- Low utility bills.
- Increase in likelihood for the property to be sold or let.
- Social Benefits.
- Improvement to the occupant’s health.
- Preservation of the natural environment.
- Increased recreation and exercise opportunities.
As you can see there are significantly more Advantages than Disadvantages of Green Building.
Green Building Rating Systems
In this section of my report I am going to give a brief introduction to the main Green Building rating systems used in the UK.
These systems review a building or construction project, and score it on different sections. Points are usually awarded for issues addressed and an accreditation is awarded depending on the amount of points scored when the project is completed.
Although I have focused on Green building in houses, I will look at some systems that are used for commercial building and civil engineering works.
Below are some of the systems I will be discussing:
BREEAM is an abbreviation for the ‘BRE Environmental Assessment Method’.
BREEAM is the leading and most widely used environmental assessment method for buildings. It sets the standard for best practice in sustainable design and has become the primary measure used to describe a building’s environmental performance.”
(Cited from the BREEAM website – www.breeam.org)
BREEAM was established by the BRE in the UK in 1990 as and aid to help measure the sustainability of new buildings.
BREEAM has grown since then with reular updates according to changes in building regulations and government legislation.
The BREEAM guidelines cover many different types of building, including Industrial, Residential, Education, Healthcare and Retail.
The BREEAM guidelines were last updated in 2008. In this upgrade, a new two stage assesment process was introduced. This means that the building will be assesed at the design stage and also after the completion of construction.
Mandatory scoring credits were introduced and a new rating level of BREEAM Outstanding was created.
The BREEAM standard is not only being used in the UK, it is fast turning into a global accreditation.
The BRE have set up a new division called BREEAM International. This division has already created versions of BREEAM for Europe and the Gulf, adapting them in accordance to local regulations.
The information below is also from the BREEAM website. This information outlines the reasons why BREEAM should be used:
BREEAM provides clients, developers, designers and others with:
* Market recognition for low environmental impact buildings.
* Assurance that best environmental practice is incorporated into a building.
* Inspiration to find innovative solutions that minimise the environmental impact.
* A benchmark that is higher than regulation.
* A tool to help reduce running costs, improve working and living environments.
* A standard that demonstrates progress towards corporate and organisational environmental objectives.”
(Cited from – www.breeam.org)
BREEAM addresses wide-ranging environmental and sustainability issues and enables developers and designers to prove the environmental credentials of their buildings to planners and clients.
* BREEAM uses a straightforward scoring system that is transparent, easy to understand and supported by evidence-based research
* BREEAM has a positive influence on the design, construction and management of buildings
* BREEAM sets and maintains a robust technical standard with rigorous quality assurance and certification”
(Information sourced from the BREEAM website – www.breeam.org)
CEEQUAL stands for, The Civil Engineering Environmental Awards Scheme.
It is a scheme for improving the sustainability of civil engineering and public sector projects, in the UK.
The aim of CEEQUAL is to encourage civil engineering companies to achieve improved environmental and social performance in the specification, design and construction areas of their projects. Launched in September 2003, CEEQUAL was mainly developed by the ICE (Institute of Civil Engineers) and various government departments and agencies also gave their support to the idea and helped to finance the initiative.
Since 2003, CEEQUAL has grown to be the main scheme for assesing the sustainability of civil engineering works. In 2008 CEEQUAL was included in the Government report “Strategy for Sustainable Construction” as a scheme to be used that can comply with the governments design agenda for civil engineering works.
Just like the BREEAM assessment, CEEQUAL uses a credits or points to score various aspects of a civil engineering project, including environmental aspects such as, water, energy and land usage, as well as other categories such as nuisance to neighbours, waste minimisation and management, archaeology, community amenity and ecology.
A project that has achieved an award from CEEQUAL will show the public that the designers, contractors and clients, have completed a project that is above the minimum environmental standards, which will portray that they care about sustainability in the construction industry.
Benefits of CEEQUAL:
* Provides a benchmark standard for environmental performance;
* Demonstrates the commitment of the civil engineering industry to environmental quality; and celebrates the achievement of high environmental standards in civil engineering projects
A CEEQUAL Award for a civil engineering project identifies an organisation that:
* Measures and compares standards of performance;
* Respects people and the society in which it operates;
* Undertakes its work in an ethical and sustainable manner;
* Acts in a socially and environmentally responsible way;
* Protects and enhances the environment; and
* Is concerned about the major impacts of construction on the environment and the earth’s resources.
Source – http://www.cpdni.gov.uk/index/guidance-for-suppliers/ceequal.htm
There are several different CEEQUAL Award levels that a project can achieve, depending on the percentage number of points scored against the scoped-out question set. These are:
* more than 25% – Pass
* more than 40% – Good
* more than 60% – Very Good
* more than 75% – Excellent
Five types of award can be applied:
* Whole Project Award, which is normally applied for jointly by or on behalf of the client, designer and principal contractor(s)
* Client & Design Award
* Design Only Award, applied for by the principal designer(s) only
* Construction Only Award, applied for by the principal contractor(s) only
* Design & Build Award, applied for the designer(s) and constructor(s) of a project.
Irish CEEQUAL Certified Projects
Below are some examples of the Civil Engineering projects that have achieved CEEQUAL Awards in Ireland in the last few years:
2008 – 2009 Awards:
* Custom House Square, Belfast
§ Derry City Centre Public Realm
§ Armagh Environmental Improvement Scheme
Award: Very Good
§ Downshire to Whitehead Sea Defences Boneybefore to Edenhalt (section 3)
§ Balloo Waste Transfer Station and Recycling Centre, Bangor
Award: Very Good
§ Moneymore Flood Protection Scheme
§ N229 Newtownards Road Environmental Improvements
§ Belfast City Centre Streets Ahead
§ Knockmore – Lurgan Track Upgrade
2006 – 2007 Awards
§ N7 Naas Road Widening & Interchange Scheme
Award: Very Good
§ Carran Hill water treatment works
* abbey & Kircubbin Wastewater Treatment Works
* Newtownstewart Bypass
Award: Very Good
(Source – http://www.ceequal.com/all_awards.htm)
LEED stands for ‘Leadership in Energy and Environmental Design’.
The United States Green Building Council (USGBC) developed LEED in 1998. The scheme was created to offer an American equivalent to BREEAM, a green building scheme that was created in 1990 in the UK.
Aswell as being a US equivelant to BREEAM, LEED was invented to help define what green building was, by recognising environment leadership in the construction industry. By doing this LEED also hoped to raise awareness of the benefits of green building and try to create some competition in the green building market.
The LEED evaluation method is voluntary and covers all types of buildings such as, homes, offices and retail space.
The main division of the LEED initiative is ‘LEED for New Construction’.
This LEED assessment is also used on some international building projects.
LEED has eight key categories where LEED points can be achieved.
1. Location and Planning
2. Sustainable Sites
3. Water Efficiency
4. Energy & Atmosphere
5. Materials & Resources
6. Indoor Environmental Quality
7. Innovation in Design
8. Regional Priority
In each of these six categories, multiple points can be achieved when specific needs have been met. The more points achieved, the higher the LEED rating will be. LEED has also introduced certain criteria, which is mandatory in each level of LEED.
The LEED assessment is a two-part process, involving a design phase review and also a construction phase review. After these reviews, a LEED certificate can be presented if the project is up to standard.
This table compares the old LEED v2.2 points system with the new LEED v3 system.
|LEED Ratings LEED v2.2 LEED v3|
|Certified 26-32 points 40-49 points|
|Silver 33-38 points 50-59 points|
|Gold 39-51 points 60-79 points|
|Platinum 52-69 points 80+ points|
(Table has been sourced from the Reed Construction Data website – http://www.reedconstructiondata.com/articles/read/leed-rating-system/)
Below is a table showing the nine different rating systems and also the five overarching categories to correspond with the specialities available through LEED.
|Green Building Design & Construction|
|· LEED for New Construction and Major Renovations
· LEED for Core & Shell Development
· LEED for Schools
· LEED for Retail New Construction (planned 2010)
|Green Interior Design & Construction|
|· LEED for Commercial Interiors
· LEED for Retail Interiors (planned 2010)
|Green Building Operations & Maintenance|
|· LEED for Existing Buildings: Operations & Maintenance|
|Green Neighborhood Development|
|· LEED for Neighborhood Development|
|Green Home Design and Construction|
|· LEED for Homes|
A comparison between BREEAM and LEED
More and more organisations are realising that having green credentials is a must in todays society.
This is because the public are more sustainably aware thanks to the increased coverage for the subject of sustainability in the news and papers.
Having a Green Building as part of your companies assets will show that you want to reduce the impact you have on the environment, as well as cutting utility bills and increasing the occupants health.
With this increase in green buildings, there is now competition between the method of assement.
For years, BREEAM has been the main environmental assessment method for UK buildings. Now with the expansion of LEED out of America there is increased competition.
The principles of BREEAM have also spread worldwide, and while similar assesment methods have been created for other countries, BREEAM and LEED are the main methods used today.
The way in which projects are assesed is the main difference between BREEAM and LEED.
BREEAM uses assessors that have been trained by the BRE, who check for evidence in the building and score it against the specified criteria. The BRE then check the assesors report and award a BREEAM certificate.
LEED on the other hand does not require a trained assesor, however points are awarded if a LEED Accredited Professional is used. Evidence from the project is gathered and submitted to the USGBC who will review it and award the appropriate certificate.
Both BREEAM and LEED help to keep the market to improve building design. Both also regularly update their scoring criteria to keep up with changing regulations.
BREEAM will more than likely be the favoured system in the UK, as it has backing from the government as they require BREEAM ratings for all of their buildings.
Below is a table that compares the similarities of BREEAM and LEED:
(Table sourced from – http://www.bsria.co.uk/news/breeam-or-leed/)
Code for Sustainable Homes
The ‘Code for Sustainable Homes’ is an environmental impact rating system for houses in the UK. The Code was launched in December 2006, and addresses new standards, above current building regulations, for energy usage and sustainability issues.
The aim of this new code is to try and decrease the impact that housing has on the environment.
The code was created to try and help relieve the problems we have brought upon ourselves through climate change. Buildings contribute nearly half of the UK’s carbon emissions. In order to reduce these emissions by 80% by 2050, housing needs to become more sustainable.
Following this code can help minimise the environmental damage that has occurred during the construction process in the past.
It also gives homebuilders the chance to create a revolutionary design for new homes to be put on the housing market, promoting a more sustainable lifestyle.
Adopting the code for sustainable homes is a major step in reaching the Government target of all new homes being zero carbon from 2016.
A house that is built in accordance to the code for sustainable homes will be more energy efficient, use less water and create less carbon emissions. This in turn is better for the environment.
Houses that follow the code are built in a more efficient way as they use materials that are from sustainable sources. Because they are built in a more efficient manner, less waste is created, and the use of recycled materials is promoted. Due to the increase in quality and efficiency, running costs will be lower than that of a traditional build.
This way of sustainable building also encourages the occupier of the house to try to live a more sustainable lifestyle.
The Code for Sustainable homes has 9 separate categories with set scoring points covering:
3. Materials used in the home.
4. Surface water run-off.
7. Health and Well-being.
When the client incorporates a specific feature they are awarded points. At the end of the build these points are added together, and the total score forms the basis of a 1-6 star rating system.
The code for sustainable homes uses a ‘star’ rating system, which ranges from 1 to 6. Level 1 equates to a 10% improvement over current Building Regulations energy standards, Level 3 is a 25% improvement on building regulations, and level 6 is a Zero Carbon house.
A home rated as 6 stars will have achieved the highest sustainability rating.
Diagram showing the points scoring to achieve each code level:
(Source – The Code for Sustainable Homes)
In February 2008, the Government decided that all new homes must have a rating against the Code for Sustainable Homes by May 2008. Also whenever houses are sold it has been made madatory that they have an Energy Performance Certificate (EPC). If a house has not been assessed for an EPC then it will receive a rating of zero.
This was brought in as an incentive for builders and developers to aim to score higher ratings in the Code for Sustainable Homes as home buyers could now easily see a house’s performance from the EPC.
Below is an copy of the EPC carried out for my house:
Diagram explaining 1*, 3* and 6* energy requirements:
Diagram sourced from – “Greener Homes for the Future”.
In 2006 the Government made publ