To show you how easy it is to make an energy model, we will use a napkin sketch to build a project in cove.tool. This is a capability unique to cove.tool; by automating the simulation inputs and reworking the energy modeling experience to be intuitive and streamlined, cove.tool has reduced the time to understand building performance from 20 hours to just 30 minutes.

Answer these two questions to get started.

• What will be the building’s function?
• Where will this project be located?

Answering these questions is the first step towards setting up your energy model. For those who need a refresher, an energy model is a series of equations that simulate the heat flow into and out of a building. You set up the conditions of your simulation by first identifying the building type and climate zone of your anticipated project. A building type is a template used to pre-load your project with relevant consumption+expenditure data, control strategies, and envelope & mechanical system properties. Cove.tool uses your building location to find and use the nearest and most recent weather file and energy code. By identifying these parameters before you even start to sketch, you are 90% of the way there.

Now that the conditions required for the energy-portion of an energy model, let’s return to the napkin sketch and identify the model-part.

Make the first pass at your building sketch. Consider these prompts as you do:

• Does the building have a compact massing?
• Is the project large, flat, tall, or thin? I-shaped or more like a U?
• What part of the project is inside and what is outside?
• What is your façade configuration? Are you ball-parking a Window-to-Wall Ratio (%WWR), or do you have a glazing design/placement strategy in mind?

Next, use the napkin sketch to make estimations of your building’s geometry:

• How tall is the building? (building height article)
• What's the total square footage? make sure you only count the area of conditioned space (i.e. what's inside the thermal envelope).
• Can you break it down the surface area of the envelope by cardinal directions (N, NW, W, SW, S, SE, E, NE)?
Use either %WWR or total surface area by direction.
• Do you include any skylights? If so, how large is the skylight area?

Example sketch+breakdown of a simple 4 story office building with 60% WWR (below).

A sketch is more than enough to start approximating the configuration, size, contextual details of your building. These estimates are the key to making the leap from daydreaming and doodling to data driven investigation.