This is one of the major challenges Rambøll is facing together with the other companies in involved in the consortium. They are responsible for providing solutions for what presently on the drawing board looks like the largest hospital complex in Europe, namely the new Århus University Hospital. If political and financial possibilities allow so, the hospital shall bring together all present hospitals in Århus under one roof.

Sustainability in a project will always be defined by the nature of the actual project and its surroundings/framework, whether for instance physical, natural, infrastructural, supply-technical framework.

In the hospital project we have chosen to work with the conception of sustainability in the original definition comprising an environmental as well as an economic and social aspect for the evaluations, where the climate like the other conditions will be evaluated on the effects in the three aspects.

Sustainability will be evaluated and planned as part of the master plan for the project. The master plan will be in preparation until mid-2009 and it includes technical, infrastructural, medico-technical and environmental design guidelines for how to perform the design. Sustainability will result in actually formulated sustainability goals for many environmental and planning conditions, based on minimum goals in observation of the legal requirements on environmental, working environmental, building as well as other legal areas. The decisions in the master plan will indicate where and on which terms project-specific sustainability goals shall be determined and decided.

The work includes technical analyses, hedging of alternatives and new technologies and legislation and economic considerations for the individual conditions. We aim to pick the bulk of the low-hanging fruits and visualise the investments/prioritisations contributing to the sustainability of the hospital. The master plan will suggest the limitation of the sustainability of the project and the potential represented by the sustainability for the project.

First of all the understanding of ‘green building’ mentioned in this quotation is purely focused on the energy consumption in buildings. This understanding of green building differs from other understandings of the term green building, which aside from energy also focus on biodiversity and materials [2-3].  

The EU GreenBuilding programme focuses on ensuring commitment from building owners and developers to become a GreenBuilding partner, as well as, endorsement from actors in the building industry.
 

This commitment to energy-efficient design is a positive contribution to the range of schemes available to building owners and developers. However, this commitment falls short if the building owner or developer aims at a holistic approach to tackling climate change or even sustainable building.  

If this is the case he or she should consider using one of the internationally acclaimed certification schemes for sustainable buildings, e.g. BREEAM (Building Research Establishment Environmental Assessment Method) or LEED (Leadership in Energy-Efficient Design), which provide sustainability assessment schemes with a wider range of issues related to sustainable building design. These schemes provide a frame by which the building owner or developer can set his/her targets and they provide designers of buildings with a tool to achieve this target.

 Lastly, the schemes ensure third-party verification of the achieved score for the project, which means that the sustainability strategy taken in the building design is subjected to a benchmarked scheme by which other sustainable building designs are also measured.   The BREEAM and LEED schemes do not in their current form (2008 versions) cover all issues relating to the sustainability of buildings, but they do cover a majority of these, and the schemes are significantly different from one another in their approach to sustainability – i.e. which issues of sustainability are weighted and scored in the schemes. Building owners and developers should therefore consider which scheme fulfils their specific approach to sustainability, whether they want to set a specific target that all their buildings have to abide by, and how this target fits into their ‘sustainable’ business strategy.  

Feel free to contact me for more information about the different schemes mentioned here (and others), and how the schemes fit your specific profile as a building owner, developer or designer. 

 References:

1.     www.eu-greenbuilding.org/ 

2.     Edwards 2003: Green Buildings Pay, by Brian Edwards,Spon Press, New York

3.     Wines 2000: ‘Green Architecture’ by James Wines, Taschen, Köln

But are passive houses really sustainable? And are they always the right answer to the climate challenge?

 

The fact, that the passive house standard purely focuses on the energy demand for peration, and in some cases, the embodied energy of the materials used in the building, does withdraw from the status of passive houses being sustainable by default (see table 1).

Sustainable buildings need not address all the themes listed in table 1, but the more themes a project considers the more holistic the approach to sustainability is.

The fact that the passive house standard does not consider whether the house is located in an area with Combined Heat and Power (CHP) with a low Carbon emission footprint (e.g. straw), is a major weakness one has to be aware of when choosing to do a passive house.

A study carried out at the University College in Dublin [3] shows that seen in a 50 year life cycle perspective, the embodied energy of the materials used for the last kWh/m  reduction needed to achieve the passive house standard, actually increased the energy consumption for the building to such an extend, that the energy reduction achieved for operation was balanced out by the increase in embodied energy.In other words – the last kWh/ m2 needed to achieve the passive house standard, actually increased the energy consumption for the building to such an extend, that the energy reduction achieved for operation was balanced out by the increase in embodied energy.

In other words – the last kWh/m2 energy savings for operation do not necessarily lead to an overall lower impact on the environment. Actually it might increase the increase the impact considering the fact that the energy consumption for operation might be changed to a fuel with lower Carbon emission than today or if the fuel for the CHP plant already has a low carbon footprint.

Based on this, the proper answer to the question posed in this blog would be that: passive houses can be a sustainable choice if the project considers the production of the house, as well as, other issues of sustainability (e.g. water consumption, waste handling, site selection and impact, procurement of materials, goods and services, and user and community interaction etc).

Basically, a passive house design should always be assessed as a possibility of reducing the energy demand for building operation in relation to the specific context that the building is located in, as well as, the other issues of sustainability. Thereby, establishing whether a passive house is the most economically, socially, environmentally and climatically sustainable solution for that specific project.

References:1.  www.passiv.de  2.   Hansen (2007): SENSITIVITY ANALYSIS as a Methodical Approach to the Development of Design Strategies for environmentally sustainable buildings. PhD thesis,

For a long time the term ‘green’ has been associated with sustainable development in the built environment and in general.
There is, however, no consensus about what the term ‘Green Building’ covers. Some actors use it for buildings with green elements or facades (with vegetation), whilst others use it for buildings which focus on low energy consumption. This is an unavoidable fact one is faced with upon a study of the literature available about green buildings (e.g. Edwards 2003, Owen Lewis 1999, Steele 2005 and Wines 2000)

As a result of this the term ‘Green Building’ is used for anything to such an extend that the term ‘Greenwash’ was invented as a label for buildings and companies which claim to be sustainable through green association but really are not.
The big question today is; ‘How do we protect the term “sustainable” from suffering the same fate as the term “green”?’For starters, the term ‘sustainable’ relates to the definition of ‘sustainable development’ introduced in the Brundtland Report from 1987: (www.worldinbalance.net/agreements/1987-brundtland.php), which states that:

‘Sustainable development seeks to meet the needs and aspirations of the present without compromising the ability to meet those of the future’  (Brundtland et.al. 1987:51)

Based on the Brundtland Report consensus has been reached about three types of sustainable development; economic, social and environmental. This is also reflected in the ISO 15392 for sustainable construction.

These days a new type of sustainability is making an outbreak from ‘environmental sustainability’. This has happened as a result of the large focus on energy-efficiency and global warming during the past decades, and the name for the new type of sustainability is suitably ‘climatic sustainability’.

In other words; sustainability is now a foursome rather than a threesome which adds to the complexity of the understanding of sustainable buildings. It does, however, also make it easier to label low-energy buildings, which until now have been kind of a naughty child in comparison with true/idealistic sustainability, as ‘climatically sustainable’.A lot of effort has been made to develop ISO standards for sustainable construction (e.g. ISO/TS 21929-1 and ISO 15392), which attempt to define what sustainability should be in the built environment. So far, the standards only provide poor explanations of how to translate the aim set in the Brundtland Report into practice. There is, thus, still an ever present threat that the term sustainable can be misused for spin in the building sector.This means that it is up to us – the practitioners and builders – to take responsibility for how we apply the term to our projects. E.g. by:

I think yes, we just recently got a mail from a big software vendor in the construction industry that informed us about they had acquired another company. The other company is developing the FEM (Structural Analytic tools) that we are using. The big vendor informed us about a 1000% increase in maintenance cost. This just happened after we have paid an upgrade fee for another product from the same big vendors, despite the fact that we already have paid maintenance for the product for years. In situations like this it is very important to be able choose product from a different vendor, and still be able to work in an interoperable way. This is one of the reasons, seen from a user’s point of view, why we need open interfaces and standard.

A global temperature rise of e.g. 2 °C will affect the energy needed to cool a space in summer negatively. If the temperature rises 1 °C the effect will be less so, but more so if the temperature rises 5 °C. The golden question therefore is: “How much can temperatures rise before my office needs to have its HVAC systems upgraded?”

To give the best answer a dynamic thermal simulation must be run and analysed.

Unfortunately, most computer programmes for thermal simulation do not include options to vary the external temperatures but offers only choices of historical weather data.

One exception to this is the programme package Virtual Environment from IES Ltd. which Ramboll has been using since January 2008.

In IES-VE historical temperatures for external air can be offset by any positive or negative value and results from different simulations can easily be compared – both with the relation to internal room temperatures and comfort parameters such as PMV. This means that the correct answer to the golden question is now only a simulation away.

As the first consultancy engineers in Scandinavia Ramboll has fully incorporated IES-VE as our general simulation tool.

The advantages and new possibilities of IES-VE are numerous e.g.:

• Full 3D modelling of simulation models
• Better analysis of concept building designs
• Complete modelling of the surroundings
• Detailed calculations of the shading of buildings (can also be animated)
• Simulation with customized HVAC plants
• Output results which include
  • Comfort parameters such as PMV and PPD (%)
  • CO2 levels in rooms (ppm)
  • Daylight factors (%)
  • Green house gas emissions (kgCO2)

If you drew a line through southern Denmark and along the same latitude all the way around the globe, the Nordic countries would be the most densely populated region north of the line. The Gulf Stream is what has made it possible for Scandinavians to live as far north and in such numbers as we do.

The extraordinary variety of changing light scenes here is unparalleled in the rest of Europe, and is something that we feel intensely and closely. While the bright summer nights of June may seem endless, we also know that light will be in short supply in winter. Daylight is a precious thing, but it is a lack we all experience. Daylight brings people together. If we do not have enough daylight, we feel cheated and robbed. Our working routines mean that in winter we rarely spend time out of doors. This is the reason why daylight plays such an important role in our architecture and lifestyle, and why we are among the few countries in the world where daylight requirements are written into the official building regulations.We demand daylight in all contexts, and particularly in our buildings. But Scandinavians are not afraid of the dark. We don’t have dark and gloomy corners here in the Nordic countries – we have areas especially well-suited to star-gazing! Compared with other prosperous parts of the world, Scandinavians still live in a society where there is no tradition of using lighting to monitor or create security for citizens. Enjoyment and relaxation are also associated with subdued lighting, and we just “looove” to light candles and create a cosy atmosphere, “pools of light”, warmth and security!

If not, then try and let me explain – In order to solve structural problems commercial software products today implement an elastic finite element model. If we take a look under the hood of these applications we might get closer to the answer. When passed a problem (mesh data, material data, boundary condition etc.) the software assembles a system of equation based on the problem data. A neat feature of these equations is that the number of equations matches the number of variables. When proposed in matrix form, this gives a square matrix which can easily be solved using standard algorithms and provides one unique solution for a given problem.

Unfortunately, this approach is not suitable when dealing with limit state analysis of reinforced concrete structures. Extensive research has shown that rigid plastic models are very good in their prediction of the ultimate load bearing capacity of such structures. So why is this model not implemented in the commercial products we use today? Well, when casting problems using the rigid plastic model, the square matrix from the elastic formulation is replaced with a rectangular matrix which contains more variables then equations. This problem cannot be solved using the standard methods, because no unique solution exists, which leads to some interesting optimization problems. Advanced algorithms are required to solve these optimization problems. Techniques for solving these problems has not been developed to the same extend as ‘regular’ methods, which might probably is the reason that these methods have not yet been implemented in commercial product.

In September 2007, Rambøll and The Danish University of Technology (DTU) launched a new research project aiming at refining existing and develop new methods for implementing rigid plastic models in commercial applications using general finite element formulations and specialized optimization software.

At present, the major advantage of using 3D construction models is to be able to visualise and make collision controls. The collision control itself internally in the individual discipline of a 3D construction model is carried out by the discipline’s own software programs.

But when it comes to inter-disciplinary collision control, ie between constructions, installations and architects, an external program is used. At Ramboll, we have commenced utilising Solibri Model Checker, which at present gives us what we need, ie a collision control where you are able to prepare reports and specific visualisation of the exact spot of the collision. In order to use Solibri, files have to be exchanged in IFC format, which is neutral. Hence, careful attention shall be paid to apply the newest software programs, which can use IFC for interchange.

Does anybody else have some good experience with the use of collision control on other projects? What are the disadvantages of other collision software programs?