Susan Smith has worked as an editor and writer in the technology industry for over 16 years. As an editor she has been responsible for the launch of a number of technology trade publications, both in print and online. Currently, Susan is the Editor of GISCafe and AECCafe, as well as those sites’ … More »
Sefaira’s performance based design platform now includes daylighting analysis
February 19th, 2014 by Susan Smith
Sefaira today announced that its performance based design platform includes daylighting analysis in their Sefaira for SketchUp product. With the addition of daylighting, Sefaira combines two critical design metrics in the same tool.
Architects can assess trade-offs between energy and daylighting to create aesthetically pleasing and high performing building designs in the conceptual design stage.
Sefaira for SketchUp is a plugin that already provides architects with real-time energy analysis without leaving their native design environment. By integrating industry leading and widely trusted daylighting engines, Radiance and DAYSIM, into this plugin, Sefaira can now deliver solid real-time daylighting and energy metrics within one single tool. Sefaira plans to add daylighting analysis to other design platforms later this year.
In an interview with Varun Singh, SVP Engineering and Development, he responded to the following questions about the new release:
What have architects done about daylighting up until this release?
Architects have relied on a wide variety of rules of thumb to improve daylighting in their building designs. These ranged from window height to floor depth based rules, and rules based on orientation of facades. However, these rules have been proven to be inadequate in informing design decisions as daylighting is a complex phenomena governed by building form, climate, space requirements, glazing design, shading design, amongst others, which can simply not be accounted for by rules of thumb. This, and the accompanying complexity of interaction between daylighting and energy use, makes it difficult for the architect’s to make performance based decisions based on rules of thumb. When architects do use sophisticated daylighting analysis, it was often to validate that their decisions were correct which is often too late to fundamentally improve the design.
Will architects be able to incorporate daylighting requirements sooner in the conceptual design phase than they were with previous methods?
Absolutely. From the very first pen stroke of when an architect starts the design process, Sefaira’s real time daylighting analysis service – Sunspot (based on Radiance & DaySIM), gives them feedback on annual daylighting performance as well as glare characteristics of their design. This allows designers to explore the daylighting implications on the fly, and unleash their creativity in order to improve daylight performance.
Are you using weather data and geographic information the determination of daylighting needs? If so, what sources are being implemented?
Sefaira’s real time daylighting analysis capabilities leans on well established rendering engines, like the US Department of Energy’s Radiance software. As part of this, we use the US DOE’s standard weather files as well as a user specified location for their building.
Can you talk a little about the tradeoffs between energy and daylight architects have made as they study form, orientation and facade design, as mentioned in your letter?
A very simple example is shading design. If an architect applies shading on a building, it often provides the benefit of reducing solar gain in the summers, which results in a reduction in cooling energy use. However, shading devices also block light from penetrating the building, thereby increasing the need for electric lighting. So the energy use reduction in cooling energy use is offset by an increase in lighting energy use, as well as an indirect increase in cooling energy because lighting itself adds heat to the building. It is easy to see that the tight coupling between energy use & daylighting in this example, where a seemingly good decision to reduce energy use, results in an increase in energy use made worse by reduced access to daylight.
If architects are doing this much analysis within SketchUp, what CAD and BIM programs are they usually transitioning to to continue on with the lifecycle, and what integration tools does SketchUp, Sefaira and the receiving CAD/BIM system have in place for making this part of the building lifecycle?
While architects prefer SketchUp as a design environment, once the design is in place, they document the model in a variety of BIM programs including Revit, ArchiCAD, etc. However, design never really stops, only the nature and scale of decisions changes. That’s why at Sefaira we have plans to provide real time analysis for our Revit users as well, to ensure continuity in performance based design throughout their design process – independent of software designers use.