Use integrative building LCA to maximize embodied carbon reduction

Why should you learn about integrative LCA in the concept design phase?

The Life Cycle Assessment (LCA) of a building involves data collection and input, sufficient knowledge of the methodology, reliable software and optimization of results. The main data inputs are material specification and quantities that are used to calculate environmental impacts like global warming potential. With the right tool, building LCA can be performed at any stage using any integration or manual input. However, more often than not LCA is performed at the Design Development (or Developed Design) stage when structural, architectural, and interior design data is available for the professional assessor. Unfortunately, there is a downside to performing LCA only at this stage. At the Design Development stage, the ability to make bigger changes tends to gravitate towards zero. Concept design stage, however, has far more potential to change design for better.

If you look at the graph above, you have the most influence and optimization power in the earliest project stages. Despite this, sometimes LCAs are done when the overall design, including structure and material specifications, is already quite advanced with little flexibility. But how do you conduct an LCA without having all the data?

One way to conduct a preliminary LCA without a model or extensive data is to use Carbon Designer. You can use it at the conceptual modeling stage, and you can easily get preliminary LCA results by entering the area and volume of your building. Carbon Designer assigns predeveloped constructions to get baseline results, and allows you to play a range of scenarios easily using high level choices. However, if you already have a basic model with early design data, you can get even more detailed LCA results that enable you to cut embodied carbon.

Integrative design LCA: using an energy model or a concept design tool?

First, let’s consider the widespread approach to the Life Cycle Assessment analysis using Building Information Models (BIM) for material quantity take-off. The undeniable advantage of using BIM for LCA is the fact that it contains full information scope about the project with all the interior, structure, architecture, and the value of the LCA is the complete analysis across all building elements. The disadvantage, however, is that sometimes BIM is available only relatively late in the project. One Click LCA has solutions to work with early phase BIM models, but if you have none at the relevant point in time, another solution is called for. Energy modeling is one solution. One solution for conducting LCA on the early stages is to use Carbon Designer tool. The advantage of this method is that it does not require any data or material sheet to get early LCA results and optimize the project according to them. Carbon Designer enables you to get quick baseline results and create easy design variations to receive immediate feedback on your project’s embodied carbon emissions. 

Another option that you may use to make your Life Cycle Assessment actionable to bring you real carbon emissions reduction is to start using energy models with LCA since the Schematic or Concept Design stage. This allows you to tie in your design decisions with the building’s energy performance (and operational energy use), and the material definitions of the building envelope or “shell” that condition part of that performance. While energy modeling deals only with the building “shell”, BIM contains information on that “shell”, its supporting structure, and interior design. The material scope is more comprehensive with BIM. So, how can energy modeling make a difference? What does it mean for you in practice? Energy model LCA gives you power to decide in the early stages of your project.

How to optimize life cycle assessment process with energy models?

The first thing that you need to know about the energy model for your future building is that it only requires a basic 3D model, within which you assign material definitions based on the expected energy performance of the building envelope. You can do this model already at the concept planning stage, change it at any time and test how your decisions influence the life cycle impacts of your project in One Click LCA, with the final goal of achieving building life cycle impact reduction. In fact, One Click LCA has native integrations with Energy modeling tools like IES-VE and DesignBuilder, among others.  

The next step is choosing the best option that suits your requirements and supplements the missing data in your model. You can do it at any point during your LCA analysis with the energy model or, alternatively, you can complete the structure modeling separately and add it to your “shell” energy model later during the Life Cycle Assessment, through Excel import or manual data entry. You can see how the missing data input looks like on the next illustration:

This happens in the following steps:

1. In the early project stage create an energy model for your project with typical solutions for walls and other layers.
2. Upload it to One Click LCA and test different options for materials.
3. Choose the best alternative.
4. As your project develops, start supplementing missing data by exporting an Excel with the materials or by entering the definitions manually, or import them from BIM. Test different design options with the newly added data.
5. In the end, you can use the complete BIM file to do the LCA, but it is not necessary anymore.

With this smarter use of integrated LCA, you can actively address the gap from the first illustration where you have the largest opportunity for the design change and significantly reduce the life cycle carbon emissions as compared to only using a BIM file in your processes.

Do you want to know how to achieve similar results with Life Cycle Costing analyses? Read our article to find out. 

In conclusion, there are two approaches to integrative LCA process and the importance and the impact of the integrations is evident in Life Cycle Assessment analysis. The choice between the BIM and Energy model LCA can influence and determine the eventual carbon emissions impact of your project, and knowing your way around integrative LCA plays a crucial role in your final LCA results.

What is the right tool to perform integrative Building LCA?

When choosing the right tool for your building Life-cycle Assessment, you have to be confident that the software will answer all your needs and deliver reliable results or maximum Green Building credits. One Click LCA is the leading market software with an extensive list of software integrations including most popular ones like IES-VE, ArchiCAD, Revit and more, top-notch automated Life-cycle Assessment process and a large global and local database with over 10,000 construction datasets. It was approved for a wide range of Green Building schemes, and has received 100% BREEAM Mat 01 rating by BRE. Moreover, is able to support up to 10 credits in LEED v4 projects (depending on regional priorities). 

Moreover, Carbon Designer, a concept phase carbon software, is able to deliver LCA results on the early phase and allow you easy design optioneering to achieve maximum carbon reduction. Download our infographic on integrative LCA now to share it with your colleagues!