Energy efficiency in BIM – the iceberg under the sugar cube

Who would have thought that the construction industry has hardly changed in the last fifty years? It was building information modeling that was the biggest stone to hit this stagnant water – and as an extra effect, the energy efficiency of BIM may make a more brutal contribution to sustainable development than ever before.

The article is based on a business talk between Dr. Attila Breznay, business strategist and coach, and Csaba Livják, founder and CEO of BuildEXT. The whole conversation can be listened to on this page or on the most popular podcast apps.

How? The construction industry has a huge role to play in achieving at least five of the 17 global sustainability goals:

Photo credit: UN

But how does this translate into daily practice? Where is the kind of utilitarianism without which long-term benefits can be immediately lost in a tender for short-term interests?

Before joining the BCSDH we did a kind of self-examination – do we really meet the aims of the organization, are we really “worthy” to join? From the inside, we have been moving towards keeping our operations on a sustainable path for some time now, so today we work under Loxone-controlled lighting, sitting in ergonomic chairs and sipping purified water, working to supplier certification regulations in a near paperless and plastic-free office environment. It’s actually where we feel comfortable, the company culture is rooted in an appreciation for the environment and people, and frankly, we don’t find it difficult to work like this.

But that is far from the point.

We work in an industry where these steps are not even the tip of the iceberg, but the sugar cube at the top.

In fact, we don’t score good points in the sustainability league table as an organization, but with the buildings, we design as an engineering office. Why?

What is BIM energy efficiency?

There is a saying in the construction industry that if you spot a mistake earlier, it costs less to fix it – the early bird gets the worm.

This means that if you notice the problem on sketch paper, you can just crumple up the paper and throw it in the bin, then redraw the concept in minutes. If the mistake is discovered at the end of the permit design, it means an extra week’s work for 20-30 engineers, and a month’s work at the end of the design. And if the problems occur in the field, during construction, that’s the real loss: the wasted workpieces, the extra work for engineers and workers, the 2-3 weeks of delays, the penalties, and the stress. If the story can be fixed at all.

When a clash is detected during construction (photo: BuildEXT)

We are all familiar with the phenomenon because that’s how construction works, right? We have to plan well in advance for errors, for which we need to set aside at least 15-20% in terms of time and money. OK, we plan like this, there we go, nothing to see here.

But there is. And it is very spectacular.

With BIM methodology, the building is not only constructed in virtual space, but also “activated”, i.e. its operation is simulated: it is operated, ventilated, loaded, illuminated, and its emissions are measured under various conditions. In this way, we ensure that faults are detected not at the construction stage, but six months or a year earlier. It is much easier, less hassle, and cheaper to modify a technical solution in the virtual space – a technician can fix in half a day what would take 20-30 engineers and contractors 2 months to do on-site.

Simple and logical, that’s pretty much how it should be:

Clash detection demonstrated using 3D simulation (BuildEXT, 2020)

How to count on technology?

We have been working with the BIM methodology for 3 years, and our experience is in line with international studies, so we can now share the following rule of thumb. The design cost for a ten billion HUF facility is traditionally around 500 million HUF; with BIM it is roughly double that, close to 1 billion HUF. The difference is huge, yet at the end of the day, surprisingly, we come out much cheaper. In fact, you don’t even have to wait until the end of the day.

What is not to be expected in the case of BIM is the HUF 1-2 billion of extra work resulting from errors and the delays and stresses that go with it. In the case of building information modeling, this phase is simply omitted. We have had the experience of comparing two very similar projects, and the difference is staggering.

This means that the extra design cost is recouped during the construction phase, i.e. within a year, by a factor of 2-3. The methodology also simulates the designed systems and the operation of the entire facility, allowing us to optimise the building’s energy consumption, use of materials and much more. This not only means that less is needed to be built in during construction, but also – and here comes the most important argument – that energy consumption is reduced by 10-15%, which effectively recoups the total construction cost over the 25-30 year lifetime of the building, not to mention the higher comfort level and the much higher value of the property.

Solar analysis of the ZenGarden office building, also home to the BuildEXT headquarter (BuildEXT, 2020)

If we look at the cost? The energy consumption of a building worth 10 billion is roughly the same as a smaller part of a city, so a 15% reduction can bring back the total construction cost. The ecological impact? Up to 50% less harmful emissions across the entire building vertical. Quality of life? A much safer construction, a better quality built environment, and a reduction in stress are invaluable.

This is the reason why in Western Europe and the Nordic region, North America, the Middle East, and the Far East, BIM is now increasingly a regulated, mandatory methodology for all attributes of major projects.

Over this lifetime, a project can save around HUF 2-4 billion in wasted energy, hidden costs, unnecessary building materials, heat loads, demolished buildings, and waste.

Of course, this is not worth it for everyone – in the case of a property built for sale, the property developer will have a very different business and development strategy than the manufacturing owner who will be producing in the plant for the next 20 years.

Is the die cast?

The added value of BIM towards sustainable development is brutal. As private individuals we would prefer to build a straw house and live in a passive house, as an office we think about the smallest ecological footprint and the quality of life of our employees, and as a responsible architectural company, we are working on a project to save the energy of an entire Budapest district. All three aspects are important, but it is the last one that really shapes reality, even for our children.

And this is no longer the level of sugar cubes, but a value-added in global terms.

The same article is also available on the BCSDH website.

Csaba Melovics

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