January 19, 2023

A Guide to Sustainable Building Design

Snaptrude Editorial Desk

What's in this post?

What's in the Blog

  • The Benefits of Sustainable Design
  • Factors that Affect Green Building Design
  • Thermal Comfort and Optimizing Heat Gain
  • Optimizing Daylighting and Lighting Control
  • Using Snaptrude + Cove.Tool to Analyze Building Performance

According to the UN Environment Program (UNEP), over 37% of global CO2 emissions came from the construction industry in 2021, rebounding and increasing by roughly 2% since pre-pandemic levels. Inger Andresen, the Executive Director of the UNEP, notes that if we do not decarbonize the construction industry significantly by 2050, we're in deep trouble.

Our goal at Snaptrude has always been to help AEC professionals deliver better buildings. This is why Snaptrude has partnered with Cove.Tool, to bring you LEED-compatible performance metrics right inside the design platform. Snaptrude users can design, visualize and analyze their projects in minutes. You can also iterate on your design collaboratively with your consultants to achieve performance targets.

Building construction accounts for over 40% of the energy demands in many countries worldwide. Despite heavy investments in building energy efficiency over the last decade, we continue to see rising energy demands across the board. 

As we work towards a more sustainable future, Snaptrude’s team looked at the fundamentals of green building design. More specifically, energy utilization and daylighting to launch the integration with cove.tool. This enables design teams to make more informed decisions to design more sustainable buildings.

Energy Utilization Analysis on Snaptrude with Cove.Tool

The Benefits of Sustainable Design

Green design principles review a project holistically. The entire building lifecycle is accounted for, from planning to construction and from occupancy to demolition. Hence the highest impact decisions are those made early on. Aside from the environmental impact associated with green building design, it can have the following benefits:

  1. Optimize the operational performance of the building
  2. Minimize building maintenance
  3. Improve indoor environmental quality
  4. Improve the overall well-being of the occupants
  5. Minimize the consumption of non-renewable resources
Sustainability Pyramid Demonstrating the Impact of Early Design Decisions

Various councils have created rating systems and certifications to support adopting sustainable design practices. BREEAM (Building Research Establishment's Environmental Assessment Method) and LEED (Leadership in Energy and Environmental Design) are the most well-known international benchmarks. In addition, numerous national-level organizations have adopted or modified these requirements factoring in local climate and materials.

These rating systems consider all types of projects, from residences to entire communities, and are used in greenfield and brownfield projects. Some countries even have codes to ensure a minimum level of green design standards in all construction. Certifications also apply to building materials and products, evaluating their impact based on embodied carbon (i.e., the CO2 emissions during its lifecycle from raw material sourcing to disposal).

Factors that Affect Green Building Design

Multi-attribute rating systems like LEED cover the entire gamut of sustainable design, from site selection to waste disposal and everything in between. Designing sustainably involves making inevitable trade offs between these factors. For example, in a cold country, materials like glass, with high embodied carbon, help reduce the heating requirements of a building.

Therefore, it's important to make calculated decisions that optimize building performance and environmental impact. 

Regardless of location, the most important attributes that apply to any design are

  1. Ventilation and thermal comfort
  2. Daylighting and lighting control
  3. Indoor air quality
  4. Material content and performance
  5. Material and waste management
  6. Water use and conservation

The most inexpensive way to build sustainable projects is by controlling these factors. Passive design principles can be adapted that respect the context and climate. For example, studying the sunpath at the site helps establish the daylight and solar radiation received by any building at that location. In addition, you can study the movement of the sun through the day and across seasons to better plan spaces. 

Sun Path Study on Snaptrude

Thermal Comfort and Optimizing Heat Gain

Mechanical equipment for heating and cooling accounts for a significant amount of a building's energy needs. Reducing the need for climate control goes a long way in making a project more sustainable.

Solar heat gain may or may not be desirable, depending on your site's climate. The amount of heat transmitted to the interiors of the building is dependent on the solar radiation incident on the building surface. Therefore, heat gain is dependent on the surface area of the building in each orientation and the type of construction or materials used.

The Effect of Climate on Building Design

Glazing type, placement, and size determine the direct heat gain of a building. In cooler countries, glazing is often maximized on the equator-facing side as it receives higher amounts of solar radiation. Conversely, the aim in warmer conditions is to reduce window-to-wall ratios. As a rule of thumb, it is recommended that the glazing in a passive system is at least 30% to 50% of floor area in cold regions and around 15 to 25% in hotter regions. The effect of glazing can, if needed, be regulated by coating it or using double or triple glazing.

Walls, slabs, and opaque construction mediums that are exposed to the sun contribute to indirect heat gain by collecting, storing, and radiating heat into spaces. Depending on the climate and building type, opaque materials are chosen for their high thermal mass or high insulation properties.

Greater the Window to Wall Ratio, Greater the Daylight Penetration

Optimizing Daylighting and Lighting Control

Daylighting helps reduce the dependency on artificial lights, and thereby, reduces energy requirements. However, too much daylight can lead to glare, which affects occupant comfort. Therefore, the goal should be to maximize visual comfort while minimizing glare and heat gain.

Needs vary according to the functionality of a space. For example, schools and office spaces can improve daylight accessibility during high occupancy daytime hours. On the other hand, spaces like theaters, conference rooms, and more controlled environments may need to be shielded from direct sunlight. 

Illumination Diminishes as Daylight Penetrates a Building

Building morphology is the primary factor determining the quantity and quality of daylight received by internal spaces. Floor Plate size, orientation, spacing between buildings, and self-shading are important parameters to consider during the initial design stages.

The illumination of a room tends to diminish as daylight penetrates into it. Generally taller and clearstory windows allow daylight deeper into a building. Courtyards and light wells may be used to supplement daylight in wider floorplates. 

Light Wells Distribute Daylight in Wider Floor Plates

Varying fenestration size by facade orientation helps achieve smart tradeoffs between heating and lighting. For example, south-side windows are great for heating and daylighting in the northern hemisphere. North-side openings can bring soft, diffused light devoid of excessive heat. Windows on the eastern or western facades need to be shaded to reduce glare.

Shading devices and vertical fins are typically used to reduce excessive glare. Sunshades can additionally be designed as light shelves, reflecting diffused light further into the building.

Both indoor and outdoor surfaces can reflect light. This can be helpful or detrimental to occupants. Reflective glass, aluminum surfaces, and lighter tones of paint in surrounding buildings can cause additional glare inside buildings. Depending on spatial needs and the orientation of windows, they can be coated to cut down glare.

Using Snaptrude + Cove.Tool to Analyze Building Performance

Measuring heat gain and daylighting manually can be challenging. Fine-tuning your design to account for these factors and iterating till you find an optimum solution can be tedious and time-consuming. With Cove.Tool’s simulation tools integrated with Snaptrude, you can save hours in model “clean up” and avoid the back and forth between multiple platforms. But more importantly, run analysis as you iterate through your designs and take the necessary decisions to make amends. Moreover, Snaptrude is a collaborative design tool; you can easily create options, rank them according to their performance and share the results directly with your client or sustainability consultant to get their feedback on the design options.

To better understand how building analyses help optimize your design, check out Part 2 of this blog. We walk you through the ins & outs of using this feature, along with a few examples of industry-standard passive design strategies analyzed on Snaptrude + Cove.tool. 

Check out Snaptrude and Cove.Tool in action by signing up to Snaptrude or scheduling your demo.