Although green building and energy performance rating systems have been implemented and firmly established in most of the world, researchers and practitioners are today still finding that building performance is not at the standard that it needs be to avoid the potential disastrous effect of climate change over the next few decades.  Unfortunately, it is clear that currently Green, Sustainable and High Performance Buildings are not going far enough, quickly enough to reduce their impact on the environment and achieve government carbon goals.

This article aims to discuss the radical changes that need to be undertaken to the design process, what changes in mindset are required and the important role Building Performance Analysis software plays in all this – “if you can’t measure it you can’t improve it” Lord Kelvin.

Sustainable design is a holistic way of designing buildings to minimize their environmental impact through:

• Reduced dependency on non-renewable resources
• A regional response to climate and site
• Increased efficiency in the design of the building envelope and energy systems
• Environmentally sensitive use of materials
• A focus on healthy interior environments
• Environmentally sensitive construction
• Meeting the needs of the present without compromising the ability of future generations to meet their own needs

A specific part of this, zero-carbon building design, is all about energy – reducing demand (loads) through climate responsive design, meeting those needs efficiently and effectively, and using renewables to deliver on reduced energy needs.  However, it must be ensured that the building offers a healthy, comfortable internal environment.  To achieve this, the industry needs to start thinking about the design process in an entirely new way, not just modify current practices.  This is what I refer to as the Lean, Clean, Green approach.

LEAN – using good design to make passive and hybrid strategies part of the solution

CLEAN – applying low-carbon technologies

GREEN – leveraging renewable technologies to a higher degree because the energy requirements of the building are now greatly reduced.

Climate needs to be the starting point - basic building design must be climate responsive, or the passive systems won’t work, and the mechanical systems won’t be small enough to be powered by renewable energy.

Performance analysis is a vital component in designing truly sustainable buildings – creating understanding of the impact of different strategies on energy consumption and other environmental metrics. Building performance analysis software allows designers to ‘virtually’ test the feasibility of different energy saving strategies and new technologies and facilitate low-energy/low-carbon designs.

This allows companies to achieve cost effective and increasingly more efficient environmental performance, while also enhancing competitive advantage, through a shift from the conventional linear building design and delivery processes to a multi-disciplinary practice of interrelated systems integration at the whole building level.

This year California in the US stepped up a gear by introducing the CALGREEN building code, mandating many green building practices that were previously voluntary.  The new regulatory code, implemented on 1^st January 2011, is the nation’s first state-wide green building code and compliance will be inspected and verified by local and state building departments as part of general building code enforcement.  It is a fairly small step on a worldwide scale but with the aim to achieve substantial reductions in greenhouse gas emissions, energy consumption and water use it is definitely a step in the right direction.

“An integrated design approach is required to ensure that the architectural elements and the engineering systems work effectively together.” IPCC report ‘Climate Change 2007’

You will have probably noticed that integrated design is a recurring theme at the moment; across BIM, other CAD tools, and processes such as Integrated Project Delivery (IPD).  This integrated information sharing approach to design teamwork is one of the key changes to current thought processes that needs to take place.  This in conjunction with a greater understanding of climate-responsive Lean, Clean, Green design makes it possible to achieve significant energy and carbon emission reductions in buildings.

Many key decisions that affect developments sustainability credentials, such as orientation, layout, form, envelope and potential passive strategies, are taken right at the very early stages of the project.  As a consequence designs are often fully developed architecturally before the impact on sustainability issues are even considered, by which time the opportunity to make a difference has passed.  Addressing these issues and getting sustainability on the agenda right from the word go has to be a key priority if the industry really wants to embrace sustainable design.

Unfortunately, the same is also often true of Building Performance Analysis – too often modelling is undertaken at the later stages of design as part of compliance and not incorporated into the process right from the start where it can make the biggest impact.

A change in mindset is required; performance analysis needs to come out of the back room and into the forefront of sustainable design – from the hands of a few into the hands of many.  It needs to be incorporated at the right level across the whole design process.  From comparative ballpark, apple with apple comparison right at the earliest stages, through to more detailed analysis and compliance at later stages.

Comparative analysis of climate, building metrics, solar, energy/carbon, light and natural resources at the early stage, using ballpark figures, can be useful to check feasibility, quantify and inform design team decision making.  It can help with those all-important master planning, orientation, massing and form decisions; justifying choices and differentiating project proposals.  Results can be used to explain and quantify to clients the sustainable impact of different decisions and tradeoffs, offering a competitive advantage.  While, feasibility conversations with engineers can easily be started early on before key decisions are set in stone.

Detailed analysis, of these and other elements such as airflow, thermal comfort, heating/cooling loads, egress and value/cost at later stages provides more accurate figures and results for system sizing, fine tuning, compliance, costing and documentation.  Again competitive advantage is achieved as results and analysis can be presented to clients and building control, justifying design decisions and providing data for effective commissioning and in-use operation.

Such a holistic approach requires the greater collaboration / integration between all parties that we touched on earlier.  As the word ‘holistic’ implies, there are a number of areas involved, and I would encourage you to look at a document that was the result of a national group of different stakeholders who spent 2 years plus developing a framework for enabling a holistic approach, which resulted in an ANSI standard (ANSI/MTS 1.0 WSIP Guide-2007, Whole Systems Integration Process).  In addition to the standard, a book titled The Integrative Design Guide to Green Building: Redefining the Practice of Sustainability was developed by some of the participants on this committee as well, and carries the discussion further.

A great example of best practice integration of performance analysis for sustainable building design is a project undertaken by our client HGA, where they integrated the IES Virtual Environment (VE) analysis and simulation to achieve LEED platinum status on the Harbour College Science Complex in Long Beach, California.  A video case study[1] looks at the process they followed to achieve such a high-performing, low energy building.

The original presentation was given at Greenbuild 2010 and a series of questions and answers follow at the end. Results track for net zero energy; with a 44% reduction in energy consumption compared to ASHRAE 90.1-2004 with 1/3 supplied by the building integrated PV system and the remainder from the campus system. There is an estimated 50% reduction in energy cost.

The analysis undertaken covered many aspects including climate consideration, building mass & orientation, room layout, mixed-mode hybrid HVAC system, natural ventilation, wind energy, solar shading, PV solar panels, energy analysis and natural daylighting.

Carbon neutral cannot be achieved without the highest level of early and continued cooperation amongst the client, architect and engineers. The ‘good design is sustainable design’ ethos promoted by quantitative analysis can make a great impact.  Architects get quick environmental feedback on design iterations and environmental engineers can input more into the design.  Achieving this kind of effective collaboration and cross-discipline understanding in my opinion is core to achieving truly sustainable, energy-efficient building design.

Stephen Choi, sustainable design coordinator at Broadway Malyan, one of our customers trialling some recent developments noticed that: “on pilot projects when the architects knew that their designs were being tested in a tangible quantitative method, the way they thought about the design started to change.  This and the analysis feedback was a learning catalyst for them.  A greater understanding of the non-visual effect the lines they were drawing started to grow and over time a better ballpark appreciation of what design elements mean in terms of energy use, solar and daylight performance developed.”

According to much of the media coverage surrounding green building, the future is beginning to look brighter.  Predicted trends for 2011 show that: the worldwide green building movement will continue to accelerate; energy codes will get even more aggressive with third party verification systems, with states and local jurisdictions making much needed changes; mandatory disclosure rules will encourage owners to invest in energy efficiency and more buildings will begin to use solar power.  These are just a few of the predictions for 2011, but if correct and the trends continue over the years we should start to see a much higher percentage of energy efficient buildings being built and refurbished across the world which will result in a much leaner, cleaner and greener future for us all.

[1] http://www.youtube.com/iesve

About the Author
Dr Don McLean is the Founder and CEO of Integrated Environmental Solutions (IES).  He has 35 years experience in the use and development of building simulation analysis tools, including involvement in many landmark building simulation projects across the UK and Europe, such as Heathrow Terminal 5.  In 1994 he founded IES for the development of the Virtual Environment platform with the objective to overcome many of the commercial barriers to the uptake of energy efficient simulation practices within design firms.  Offering an integrated suite of performance analysis tools within one platform, IES continues to develop its tools making them more and more accessible to architects and the mainstream building sector.  Don holds a BSc in Environmental Engineering from the University of Strathclyde, and also spent nine years in the ABACUS unit, at the Department of Architecture in the University of Strathclyde, undertaking a PhD and Post Doctoral research.  During this time ABACUS was one of the foremost departments in the application of computers in the building design process.