Energy Efficient Buildings Design: The Undeniable Truths

Energy efficient buildings are now more of an industry catchphrase.

Using it sounds modern, and projects get the tag of “green construction.”

However, the real question is,

Does the design reduce your electricity bills?

Calling a building energy-efficient really does not quantify in numbers when it's about bills.

Today, the market wants to see the “efficiency” in action, rather than witness it as a passive effort.

Against the current backdrop, a developer can tag a building “green” with LED lights and solar panels.

They do this to attract investors, marketing, and charge more without reducing any real numbers. The industry is currently torn between the perception of green being expensive and trendy, with green being smart and cost-saving.

This has led to green designs often costing more upfront, without lowering the energy usage of the structure.

Green Designs Often Increase Capex without Lowering Opex

Most of the green designs today seem to be sustainable, but barely have any impact on the bills.

Existing buildings and construction projects in pursuit of LEED points often install green upgrades, like glass walls, fancy facades, or designer solar panels.

This leads them to overspend in the initial phase, while the ROI is not that pleasing within a few years. Owners realize that things did not work out the way they thought and believed. And, there is no turning back; the only thing is to replan the sustainability elements in the structure, or bear the bills.

For instance, a building may have expensive double-glazed glass, but if the HVAC design is oversized, the bills will still stay high. Hence, fancy installations only sound and look sustainable, without any real-world, measurable impact.

Now, in the above situation, what many might have missed is the additional scope behind the scenes.

Have you guessed it?

It is there in HVAC sizing, which, if optimized beforehand, would also have added to energy savings.

With the advancements that technology has brought to the construction industry, nearly 80% of the energy costs are decided in the early design phases.

Importance of Early Design Optimization for Energy Efficiency

When designs are optimized thoughtfully, considering all the parameters and data available, they create a huge impact on your electricity bills.

Different energy-consuming systems can be optimized and coordinated to run with efficient usage of resources.

Thinking of sustainability as installing various gadgets later on would not be of much benefit today. The real solution lies in the fundamentals of architecture, structural, and most importantly, MEP designs.

Installing ACs that are branded with energy-saving features never adds up to an impactful, sustainable measure.

Even though energy-efficient lights are widely available, they do not reduce your electricity bills. This may hit hard, but what we are going to reveal in a few seconds will hit harder.

Uncovering the AECO’s Uncomfortable Design-Stage Realities

By the time handover is complete and the building is in operation, the cost curve is already set.

Here are the hard truths that make the industry squirm,

Building Orientation Mistakes

Inefficiencies get baked into the early stages of planning the building’s orientation.

The position your building is in substantially affects how much is absorbed during the daytime.

Controlling the amount of heat absorbed is the key here to lighten the load on HVAC systems. For instance, if the building faces have expansions in the east-west direction, and then if there are long facades installed, that is a concerning situation.

The orientation itself is forcing the building to fight the direct heat, which in turn increases energy consumption.

Errors in HVAC Sizing

HVAC sizing should be optimized during MEP designs, and even in the modeling phase, for better outcomes.

There are advanced integrations available today that use machine learning and AI insights to predict the HVAC performance over time.

Additionally, unnecessary glazing areas in the building add up to heat gains. Zoning of the AC outlets should be well-thought-out, as any gaps there would lead to over-conditioning or under-conditioning. Sustainable materials with good insulation, in walls, roofs, foundations, and windows, reduce the required tonnage that is caused due to poor envelope insulation.

Window Placement

While placing windows, people often have a focus on the looks.

However, most of the time, larger windows, especially if facing east or west, and wrong head heights also kill heat distribution.

These are the mistakes that increase the requirement for artificial lighting, heating, and cooling of the building. Also, it impacts the interior aesthetic of the building negatively, which causes the experience of the residents to be unsatisfactory.

Inefficient Space Planning

While planning the interior architecture of a building, the various spaces and their functions need to be placed thoughtfully.

When that is not done, systems inside the building do not operate cohesively. For example, if heat-generating areas, like kitchens and server rooms, should not be clustered.

Further, the zoning of ACs, if done logically ,can result in efficient cooling of the floor. If ACs are placed at places where the cooling is max effective, it will result in savings of electricity directly.

So, these were the hard truths that the industry is still avoiding. If these mistakes are avoided and the points are thoughtfully considered, buildings can be truly energy efficient.

While these were the fundamental things to be considered, there are several interesting actions that enhance energy efficiency naturally. These are:

Passive Cooling and Shading

These things protect the building on a daily basis and form an integral part of its resilience over time.

For example, roof overhangs work great as a shield for the windows and walls. It protects from direct sunlight, snow, or rain, which helps prevent damage from moisture, enhancing durability and aesthetics.

Cross ventilation is also a widely used measure for naturally conditioning the air and heat transfer inside the floor. It acts on the smart flow of air from one side of the building to the other side, where the fresh air comes and pushes out the stale air from the other side.

As the fresh air goes out from one window, more fresh air comes naturally to fill that void. This happens in microseconds, but creates an all-day-long flow of fresh air and natural ventilation.

Building Courtyards

Courtyards create not only aesthetic but functional green spaces in your buildings.

It becomes a central spot for natural ventilation and removes greenhouse gas emissions, a great and relaxing spot for social connections, etc. While mostly suitable for commercial buildings, these bring vivid greenery, like flowers and shrubs that are native to the place, along with water features, etc.

Placing these also creates microclimates inside the building, with cooling air in hot/arid regions and refreshing air in humid climates.

Adding sensors to lights

This measure is perfect for corporate settings, as lights are not often switched off after every use.

When energy efficient appliances, like LED lights, are equipped with sensors, there will be zero loss of energy. This means the use of natural lighting and over lighting will also be reduced, which will result in savings in bills, without compromising brightness, and have energy efficient lighting.

Till now, we have seen various methods to reduce energy usage. To summarize:

Early design-stage optimization,

Use sustainable materials but not just for aesthetics, but also for functional purposes,

Natural lighting and intelligent insulation, and many more.

The real thing that can fuel all these things is Building Information Modeling (BIM).

BIM in Action to Reduce AECO Energy Usage

It is because of BIM that all these optimizations and strategic placements of things are no more guesswork.

If these were done without accurate calculation and technical confidence, they would have failed to deliver their purpose.

How does BIM actually help?

Intelligent BIM-driven energy modeling systems use 3D BIM models to simulate the energy flow in a building. The flow is not just for visualization, but also holds precise technical accuracy.

This enables BIM professionals to understand the real-world situation closely, even when the construction phase is far away. Realization of the energy flow and inefficiencies in the design affecting the usage gives designers a huge advantage.

BIM software and tools from recognized entities offer material optimization for sustainability during, right from the procurement process and help buildings achieve the "Energy Star."

It suggests the best sustainable building materials alternatives for each and every corner of a building. This gives a great advantage during early phase optimization for sustainability.

Without BIM, energy efficient buildings today would not have been possible to this extent, as the industry is looking forward to a greener future and processes.

Now, everything that we have known till now aims to save money on bills. So, there is the actual deal. The processes, strategies, and hacks mentioned reduce operational costs and keep upfront costs in control.

However, if we arrange them in order, based on their effectiveness, here is the order.

The Ones that Save Money the Fastest

While all of the measures are effective, some serve faster than the other ones which are more focused on long-term benefits. Here is the clear order, so you can choose the best ones:

• Optimized HVAC sizing for lower-energy usage
• Proper zoning of ACs
• Strategic orientation
• Passive cooling and shading techniques
• Envelope enhancements
• Solar panels

Why aren’t solar panels the first step towards energy efficiency?

We explored that building architecture, orientation, and window placement, and wall insulation are very critical to energy efficiency.

But if a building is designed without considering orientation or has improper HVAC sizing, it would not be fixable with solar panels. That building might have been designed five or ten years ago, and now adding solar panels would not make it “green”

If there is already a load on the building’s heating and cooling systems, solar panels would not reduce that load, despite using one of the most abundant renewable energy sources.

Additionally, the climate also greatly influences the efficiency of solar panels.

Hence, solar panels are like the last 20% addition to the 80% measures you have taken first.

Window-to-wall ratio, envelope decisions, shading strategy, courtyard creation; these things bring the most amount of energy savings.

Final Thoughts

The industry is still not considering the energy efficient upgrades that give rise to energy efficient homes.

The reason behind this is that most of these measures lie in the foundation.

Hence, they are of low appeal in the market, and investors are not attracted to presentations mentioning those measures. The change needs to come from the root, where people should understand that rooftop gadgets and fancy facades do not reduce energy bills.

Instead, a structural orientation, HVAC sizings, window placements, and a lot of architectural and structural aspects determine whether a building's energy use is efficient or not.

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