Sustainability Week on WCN: Certifying buildings

Vania Goncalves 21 Oct 2016 GLOBAL ENERGY & UTILITIES

Whether buildings are comprised of commercial, residential or office space, they can be assessed, rated and certified according to their green and sustainable features.

There are several certifications that honour projects and buildings designed and built to be environmental-friendly and resource-efficient.

As part of WCN’s sustainability week we present three internationally recognised certifications — BREEAM, LEED and Passivhaus standard — worth knowing about.

Passivhaus standard

The Passivhaus Standard or Passive House is a comprehensive low energy standard developed in 1990 by physicist Wolfgang Feist.

Six years after, the Passive House Institute (PHI) was created to further develop, promote and control the standard.

The first pilot project to achieve Passive House standard was constructed in 1990 by Dr Feist in Darmstadt, Germany. The Kranichstein Passive House was Europe’s first inhabited multi-family house to achieve a documented heating energy consumption of below 10 kWh/(m²a).

Zeno Bastian, PHI’s head of the department of building certification, says: “High quality of planning and construction is a key for achieving such a low energy demand.”

For a building project to be considered a Passive House it has to meet a set of criteria. These include:

•    the Space Heating Energy Demand is not to exceed 15kWh per square metre of net living space (treated floor area) per year or 10W per square metre peak demand;
•    the Renewable Primary Energy Demand, the total energy to be used for all domestic applications — heating, hot water and domestic electricity — must not exceed 60kWh per square metre of treated floor area per year for Passive House Classic;
•    airtightness has to have a maximum of 0.6 air changes per hour at 50 Pascals pressure (ACH50), verified with an onsite pressure test;
•    thermal comfort must be met for all living areas during winter as well as in summer, with not more than 10% of the hours in a given year over 25°C.

“Passive House has only one set of criteria and these have to be met — if they are not, it’s not a Passive House,” says Bastian.

The criteria are achieved through the design and implementation of five Passive House principles: thermal bridge free design; superior windows; ventilation with heat recovery; quality insulation; and airtight construction.

Last year, the Passive House Institute introduced new classes, which focus on ‘primary energy renewable’ (PER). In addition to the Passive House Classic, there is now the Passive House Plus and Passive House Premium.

Bastian says: “The building quality, insulation, heating and cooling demand is the same for all classes, only the technical systems and renewable energy usage is different in different classes. But in all three classes you have a full Passive House that it’s very energy efficient.”     

Buildings and projects wanting to obtain the certification have to go through an application process. The first step is to contact a certifier, says Bastian. He adds: “There is a large number of certifiers in many countries all over the world. You ask a certifier for an offer for certification and then you decide whether to accept.”

The certifier, then, carries out a first check about basic certification boundary conditions, followed by a main check, which is generally done shortly before the construction starts. Bastian says: “When the planning is more or less finished and all the systems are checked and the Passive House Planning Package is checked, this is the most thorough check in the certification process, and if everything is fine construction can start.”

“If there’s something to be changed there’s a note by the certifier stating what has to be changed to achieve Passive House standard.”

After the building is complete, an airtightness test report has to be submitted, along with the ventilation system commissioning test report.

He adds: “We also need a declaration by the construction site supervisor saying that all the planning submitted has been implemented on site and if there have been any changes to the planning during the construction process.

“If the criteria are complied with then the certificate can be issued.”

Any type of building can be certified — even pools and supermarkets, says Bastian. “For very special types of buildings like swimming pools the criteria has to be adapted and that can be clarified with the Passive House Institute at the beginning of the certification process. There’s not really a limit to which type of buildings can be certified. It’s also possible to certify a building which has already been constructed and completed, but then if there’s anything wrong with it, it will be more difficult to fix.”      

He adds: “Passive standard can be applied worldwide in any climate, so the requirements are made in a way that they fit in any climate, from Dubai to the Arctic.”

Besides having a building that is energy-efficient and comfortable to live, the certification also adds value to it, according to Bastian.  

“The certificate adds to the value of the building, if it is a certified Passive House then potential buyers will be made more confident to buy,” he says.

Looking into the future, Bastian is certain that the Passive House basic principles are so effective that there is not a necessity to change. “The basic principles will probably not change, what will change even more are the products and components for building Passive Houses. And they will be cheaper than now, making it even more economic to build Passive Houses.”

Eldorado Crescent, a two storey detached single family house, has achieved Passive House standard. Image by Samuel Ashfield.

BREEAM Certification

BREEAM — Building Research Establishment Environmental Assessment Method — was created 25 years ago by the Building Research Establishment (BRE) in the UK.

Its creation was based on the need to assess the sustainability of buildings.

Martin Townsend, BRE director of sustainability, says: “We were the first scheme that was created to measure the sustainability of buildings. It started by a number of well-informed developers saying to us, we really want to demonstrate that our buildings are better than the ones that are being created in the marketplace. Lots of people 25 years ago were making claims that their buildings were green or more sustainable and actually there was no real way of measuring that success.

“That process of measuring performance was very much around energy, but now we’ve got a scheme that covers much more than energy, it looks at healthy wellbeing, performance, waste, a number of much wider factors. It really rewards people for going beyond regulation just not in the UK but worldwide.”

BREEAM has evolved in other ways as well. Now, it not only focuses on individual new buildings at the construction stage, but incorporates the whole life-cycle of buildings from planning to in-use and refurbishment.

It runs the following schemes: BREEAM New Construction, BREEAM International New Construction, BREEAM In-Use, BREEAM Refurbishment and BREEAM Communities.
Townsend says: “What we are keen to ensure is that every phase of the life-cycle of a building has a way of measuring improvement. So, we are always trying to promote people to do better than the regular minimum and that process is basically how all the other BREEAM schemes came to be.”

Assessments are carried out by independent and licensed assessors that rate buildings on a scale of five levels: pass; good; very good; excellent; and outstanding. The final score is achieved by the awarding of points — called credits — to buildings or projects in several categories, including energy, health and wellbeing, innovation, land use, materials, management, pollution, transport, and waste and water.

Townsend says: “We don’t reward people for what they should be doing because that would be negative. We reward people through the award of credits when they go beyond the regulation minimum and you start to see some great consequences. You see all sorts of mechanisms to drive sustainability where design engineers and architects get inspired to do more.”   

He adds: “We don’t restrict people, so some clients might decide that they are going to make their building very energy-efficient so what we have is a structure within the BREEAM standard where there are certain minimum criteria you have to go through.”

The certification process starts when an assessor is asked to register a building project. Once registered, assessors will work with the client on its design.

Townsend adds: “In that process the assessor will be advising, supporting and explaining what is best practice, they will probably do a pre-assessment calculation of what that means. Once the design is finalised, it is submitted in terms of design stage certification.

“When that building then gets designed and constructed, we then do a post-construction review. The post-construction review is to make sure that what was designed or specified has been built and if there has been changes what the impact of those changes are in the overall certification process.”

In the certification process the assessor has also to submit the BRE evidence — photographs, invoices, or testing results — to demonstrate that everything that was agreed has actually been done.

After, credits are awarded and certification given. Even though it’s not advisable that a completed building applies for certification, it can be done, according to Townsend. “[A building when complete] can apply, a number of buildings do, but because there is a large amount of information that is required and because generally you are looking to go beyond regulation there is a chance that you might not achieve a very good score, because what we are looking to do is make sure that we’ve got evidence that that building is really achieving the credits that are required,” he says.

According to Townsend, the requirement and criteria set to achieve BREEAM are expected to change in the future. “As regulation constantly changes we update our schemes, so we go through a two-year cycle where we research, review, and talk to the industry and as regulation moves forward our standards move forward.”

With the standard already in 77 different countries, Townsend believes that each country has something to offer in terms of sustainable and eco-friendly features.

“Every country has something to offer in terms of best practice. So if you look at what is going on in some parts of Scandinavia there is great work on materials, if you look at what is going on in Germany there is a great work in terms of energy efficiency and passive design. If you can pick that best practice and share it easily between different countries you are creating a great way of sharing that knowledge to help the industry accelerate best practice and knowledge transfer as quickly as possible.”

The Hub, Broadgate Estates headquarters, is BREEAM Outstanding certified.

LEED Certification

U.S. Green Building Council (USGBC) was established in 1993 by Rick Fedrizzi, David Gottfried and Mike Italiano to promote sustainable practices in the construction industry. It was then that the idea for the creation of a green building rating system, which would later become LEED or Leadership in Energy and Environmental Design, came to life.  

The rating system was unveiled in 2000 and since then it has become an international standard in certifying environmentally-friendly buildings and projects.

Leticia McCadden, media relations manager at the USGBC, says: “LEED provides building owners and operators with a framework for identifying and implementing practical and measurable green building strategies for all building types from commercial buildings to entire neighbourhood communities. LEED certification promotes electricity cost savings, lower carbon emissions and healthier environments for the places we live, work, learn, play and worship.”

Projects applying for LEED certification earn points across several categories that address sustainability issues. Each category in the rating system consists of prerequisites, required elements or green building strategies that must be included in any LEED certified project, and credits, optional elements or strategies that projects can elect to pursue to gain points toward LEED.

McCadden says: “LEED prerequisites and credits work together to provide a common foundation of performance and a flexible set of tools and strategies to accommodate the circumstances of individual projects.”

She adds: “LEED rating systems generally have 100 base points plus six innovation in design points and four regional priority points, for a total of 110 points. Each credit is allocated points based on the environmental impacts and human benefits of the building-related impacts that it addresses.”

Projects are then given a certification classification of either silver, gold or platinum, based on their points total.

To ensure that the LEED criteria are met, the Green Business Certification Inc. reviews and verifies the project or building quality. The standard provides resource and utility savings, lower carbon emissions and healthier environments.

According to the USGBC’s 2015 Green Building Economic Impact report, between 2015 and 2018, LEED-certified buildings in the United States are estimated to achieve $1.2bn in energy savings, $149.5M in water savings, $715.2M in maintenance savings and $54.2M in waste savings.

LEED certifies all type of buildings — from homes to corporate headquarters — at all phases of its lifecycle. There are five rating systems: the Building Design and Construction, the Building Operations and Maintenance, LEED Homes and Neighbourhood Development.

McCadden says: “While there are different requirements for each rating system and each LEED project team has a different set of goals, LEED credit categories focus on: location, sustainable sites, water efficiency, materials and resources, indoor air quality and innovation.”

According to McCadden, one of the most frequently achieved LEED credits is related to the recycled content. “LEED project teams are finding useful ways to recycle and reuse both water and material. In addition, the sale of low-flow water fixtures and waterless urinals have dramatically increased over the last ten years,” she says.

LEED v4 is the newest version of the standard and was created to be accessible to a wider range of building and space types so they can achieve higher levels of environmental sustainability, while also being flexible for projects outside the US.

Changes included:
•    a focus on materials that goes beyond how much is used to get to a better understanding of what is in the materials, and the effect these components have on human health and the environment;
•    a more performance-based approach to indoor environmental quality to ensure improved occupant comfort;
•    bringing the benefits of smart-grid thinking to the forefront with a credit that rewards projects for participating in demand response programs;
•    providing a clearer picture of water efficiency by evaluating total building water use.

The rating system has evolved over time and McCadden is certain that this will continue to happen: “Performance scoring through LEED on platform is the next wave in integrated design and operations, helping building owners and operators measure the sustainability performance of assets in their portfolio, and compare their portfolio against other portfolio owners globally.

The U.S. Green Building Council headquarters is LEED Platinum certified. © Eric Laignel

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