So part of my list of things to do for 2017 was to tackle a better workflow for documenting energy compliance when our designs go to the city for permit review.
The City of Seattle has a 2012 requirement to ensure buildings meet, and hopefully exceed energy performance. As Architects we work with our consultants and team mates to determine the buildings are adequately insulated, properly ventilated, heated, cooled and well lit. There is a little horse trading with design to get the space we want with the appropriate energy performance. After all, you can’t get a naturally well ventilated, day lit space without windows!
The Architect’s job is to show compliance to the Building Energy Code. They do this either by a component or prescriptive method. The component approach is by calculating all the external building envelope areas and multiply them with the U-Value. At the end of the calculation your building needs to be less than the benchmark set by the City. If this is not the case, you are in full building energy simulation and into the prescriptive approach.
Is it easy to document? The answer is no! Your building is constantly changing through design and the current process of checking compliance is time consuming and works better with a static envelope. Calculations are usually performed at milestones; but wouldn’t it be better if you could get feedback from your model in real time, really informing your design rather than complying?
The documentation in itself is time consuming. As with everything in Revit, there are multiple ways of approaching a task; but what’s the best? There is the laborious process of creating every wall assembly, adding the thermal conductivity and specific heat to all the materials, entering each components thickness to calculate the R and U values. It gets complicated when combining multiple elements into an assembly, such as a glazing and mullions. The advantage with this approach is that when the building changes, so too does the schedule. It does however mean that the team really needs to be integrated and understand what is happening to the assemblies, materials, schedules and model appropriately. A tall order when teams are scrambling to get the work done and members have varying skill sets with the tool. The other approach involves an individual to demarcate areas of building assemblies and assign the appropriate U-value – currently performed in Revit as Region Fills with scheduled material areas.
There are some that feel incumbent to create their own unique approach. This week I heard a colleague export elevations to CAD and reinsert these back into Revit within area plans to trace boundaries for the specific assemblies. I applaud the ingenuity, but to rely on a method that requires manually importing/exporting to another format and exhaustively tracing lines does not help in the workflow. Multiple area boundaries also have a tendency to hinder model performance and in turn, grind the laborious process further.
So what are our options? My current idea is to have a mass, split its face and assign the corresponding wall assemblies as painted materials with U-value parameters built-in. If the mass model could smartly update to the building envelope and somehow read the materials from the facade, projecting them onto the mass to schedule, we would be in business. I am hoping we can crack this nut as it will be a huge time saver to our Seattle teams. I believe this will start with massing, journey into Dynamo and probably end with some Rhino and Grasshopper.
If you have any bright ideas, please share as I would love to hear your thoughts. I will continue to post developments, so come back soon to how this project is progressing.