Goals

  1. Understand how Performance-Based Design works
  2. Learn how you can understand and influence the performance of your building
  3. Sign off for our biweekly Training Webinar.

Performance-based design is an iterative, three step process in which you continually assess how your building is performing, what is driving that performance, and what you can do to influence it.

Download a sample model to walk through the core training exercise:

1a. How is my building performing?
The Sefaira Dashboard

The Performance Dashboard is designed to give a quick snapshot of energy and daylight performance as the design evolves.

energy-use-intensity
Energy Use Intensity or EUI is a building’s annual energy use per unit area. It is typically measured in thousands of BTU per square foot per year (kBTU/ft2/yr or kWh/m2/yr). EUI is useful for compar- ing performance of buildings across sizes, types, and locations. It can help you design buildings with low energy use, and, as a likely result, lower operating costs. The color of the dial also shows whether the building is meeting 2030 Challenge targets (when it is green) or not (when it is red).

The Energy Segments dial further breaks down the EUI into four major categories of Heating (red), Cooling (blue), Lighting (yellow) and Appliances (purple). This example shows a building in which the majority of the energy use is from heating the building.

daylighting
The Daylighting dial shows the percentage of floor area that is “well lit” (Spatial Daylight Autonomy, shown in blue), “glare” (Annual Sunlight Exposure, shown in yellow), and “underlight” (shown in grey) in line with LEEDv4 metrics.

1b. Setting use type, location and baseline. How did performance change?

Setting up real time analysis so that Sefaira provides meaningful feedback on the performance of your design only requires three inputs; a use type, location/climate zone and baseline.

TIP

You can see the assumptions Sefaira is making about these use types here.

core4
  1. Choose a building type of either Office, Residential, School, Healthcare or Laboratory.
  2. Enter a location, Sefaira supports locations all over the world.
  3. Choose baseline and climate zone (climate zones are only set for ASHRAE 90.1)

core5
Setting a baseline
  1. Chose from either a Standard Baseline, including default ASHRAE 90.1 and Part L, or adjust the sliders to create your own custom baseline which can be recalled later on to quickly re-apply to other projects.
  2. Clicking on the slider will show the exact parameter value and units.
  3. Daylighting Based Controls account for the impact of good daylight on your buildings lighting energy use.
  4. Click to return to the Performance Dashboard.

core6
After setting those three inputs we can see that our school being built in San Francisco, with an ASHRAE 90.1 for 2010 energy base- line, is currently not meeting the 2030 challenge (the dial is still red). The building is cooling dominated and we would need to look at the Element Performance chart to better understand why. Lastly, this design needs some attention given to improving daylighting since there is mostly glare.

2. Element performance graph: digging deeper

The Element Performance graph shows which building elements are responsible for heating and cooling loads. Red flows indicate negative (bad) contribution towards either the heating (on the left) or cooling (on the right) loads. Green flows indicate positive contributions towards either heating or cooling loads.

TIP

Hovering the mouse over any of the elements will allow you to see the exact values of those loads, and clicking on the elements allows you to adjust the baseline proprieties which corresponded to the load.

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TIP

The element performance diagram automatically orders the largest gain at the top down to the smallest at the bottom.

core8
This Element Performance chart is showing our design has high heating loads due to our wall conduction. Reducing the building envelope area would be one solution to decrease the heating load. Alternatively we could decrease the load on heating by improving the insulation of the walls by changing the R-value or U-factor

core9
This Element Performance diagram is showing our design has large loads to the cooling system due to South and West solar heat gains. Several different strategies could be explored to lower the loads to the cooling system. Reducing the amount of glazing on these facades, effects of adding shading or changing to better performing windows (reduce Solar Heat Gain Coefficient).

3. Mitigating strategies

Depending on the building elements that mainly drive your building’s performance you need to apply the strategies that will mitigate these effects.The table below lists the main building elements and strategies you canapply to improve the performance of your building:

To affect these phenomena…
…Modify these design elements:

Wall / Roof / Floor Condition
strategies_1
  • Reduce envelope area (e.g. a more compact building form)
  • Improve insulation levels (change R-value or U-factor)

Glazing Conduction
strategies_2
  • Reduce glazing area
  • Improve window insulation (U-factor)

Solar Gain
strategies_3
  • Reduce glazing area on sun-facing facades
  • Add shading
  • Improve glazing properties (reduce Solar Heat Gain Coefficient)

Infiltration
strategies_4
  • Reduce leakage. (This is primarily an issue of detailing, and is dealt with as a single “leakage” value in Sefaira.)

Lighting
strategies_5
  • Specify more efficient lights. (Reduce Lighting Power Density)
  • Consider daylight-based lighting controls, which turn off electric lights when sufficient daylight is available.

    (See “daylighting” below.)

Appliances/Equipment
strategies_6
  • Specify more efficient equipment, or install systems that reduce “vampire loads” (power consumed when devices are in “standby” mode). (Reduce Equipment Power Density)

Ventilation
strategies_7
  • Reduce ventilation rate (if appropriate – ventilation rates are often governed by code requirements)
  • Use a mechanical heat recovery ventilator (HRV) or energy recovery ventilator (ERV), which uses exhaust air to pre-condition fresh air.

Daylighting (sDA)
strategies_8
  • Use narrow floorplates
  • Add glazing (especially high windows)
  • Improve glazing properties (T-vis, or the amount of visible light the windows let in)

Glare (ASE)
strategies_9
  • Reduce glazing area (especially on sun-facing facades)
  • Add shading

4.Sefaira Architecture BiWeekly Training Webinar

This bi-weekly training webinar is divided into two parts. The first part, from 12:00pm-12:40pm EDT is a lecture style course geared towards beginners (from firms with an active Sefaira subscription, students from a learning institution part of the Sefaira Education Program (SEP), or prospective customers considering Sefaira Architecture) who have never seen the Sefaira Real-Time Analysis for SketchUp and Revit plugins or the Sefaira Web Application. In this session attendees will learn how to:

  • Build an architectural model in SketchUp and Revit that will run smoothly in Sefaira
  • Interpret the interface within the Real-Time Analysis plugin
  • Generate a daylight visualisation
  • Set up a project in the Sefaira Web application and create different strategies

From 12:40 – 1:00pm EDT the Sefaira instructor will conduct office hours where users are encouraged to drop in and ask any questions related to Sefaira Architecture and their project.

WHAT YOU’VE LEARNED

  • You can now understand how your building is performing, both in terms of energy and daylighting
  • You have learned how to understand in more detail what is driving your building performance
  • You know what the best strategies are to overcome the most common building performance issues