The data bar (right hand side of the screen) calculates metrics about your design as you draw. Here are some details on how it's done.
The Data Tab
Which Sections (geometries) Are Used?
The data tab considers sections as Building Sections where:
- type is buildingSection
- floorToFloor is a number
- levels is a number
- geometry is a polygon
- are owned by Giraffe ie. appId is '1'
Calculating Section Area
3 types of area for each Building Section are defined:
- Gross area : The total area * the number of levels. This includes the area of the roof where:
- parkingType is "multi-deck"
- rooftopParking is true
- Net area: Gross area * efficiency
- Saleable area: Gross area * sellEfficiency
levels, floorToFloor, efficiency, sellEfficiency, parkingType, rooftopParking are defined in the sections properties, or inherited from categories such as usage.
Site Area & Barchart
Site area is the area of the project boundary. It is broken down into:
Building: The area (within the project boundary) of the footprint of all building sections
Hardscape: The area (within the project boundary) of all roads, paths/pavements, on-grade parking lots, and plaza sections.
Open Space: The remaining area within the project boundary.
The FSR is the sum of all building section net areas divided by the site area.
This includes building from outside the project/site boundary.
The maximum height of any building section.
The total gross area * levels of all sections where
- parkingType is "underground"
GBA, NFA & NSA
The total areas of all building sections. See "Calculating Section Area" above.
Area By Use & Barchart
Area by use aggregates sections' net areas by their usage property.
A section is assigned dwellings if its usage property starts with "resi" (case-insensitive), or it has all of the following 3 properties:
- dwellingSize, dwellingMix & dwellingResidents
Each of the above properties is a list of 3 numbers corresponding to 1, 2 and 3 bedroom dwellings.
Dwellings are assigned to sections based on the desired ratio specified in dwellingMix.
The size (in m2) of each type is specified in dwellingSize.
The number of residents in each type is specified in dwellingResidents.
defaults (for sections with usage starting with "Resi") are:
dwellingSize: [35, 85, 110],
dwellingMix: [0.5, 0.4, 0.1],
dwellingResidents: [2.1, 2.1, 2.1]
The sum of each building section's net area multiplied by its parkingRequired property. The unit for this property is carparks/m2. If this property is not set on a section, it defaults to 0. Hovering shows the breakdown by usage.
The sum of each parking section's gross area multiplied by its parkingProvided property. The unit for this property is carparks/m2. Hovering shows the breakdown by carpark type.
Total paved area broken down by:
- Roads - total of all roads.
- Footpath - total of all footpaths.
Roads and footpaths do not account for buildings or anything else placed on top of them. The covered area will be counted
- Parking lots: total parking lots that are not covered by roads, pavements or buildings.
- Plaza: total plaza sections that are not covered by roads, pavements or buildings.
The area of the union of all sections of with property type of landscape which is not covered by buildings, roads, pavements, on grade parking lots or plaza.
The total number of residents are calculated by the dwelling mix above.
The sum of each building section's net area multiplied by it's jobs property. The unit for this property is jobs/m2. If this property is not set on a section, it defaults to 0.
Space / Person
Landscape (as above) per Resident (as above)
Total facade area (The sum of each sections perimeter * floorToFloor * levels) of all building sections.
Floor : Facade
Gross area total / facade area
Net Present Value is defined by:
totalSalePrice / Math.pow(rate + 1, constructionTime);
Where totalSalePrice is each sections saleable area multiplied by its salePrice property. Default is $10,000/sqm
constructionTime is set in Giraffe appdata in the public.financial property. If it is not specified, it defaults to 12 months.
The sum of each sections net area multiplied by it's buildCost property. Default buildCost is $3,500/sqm.
The facade area of each section multiplied by it's facadeCost property. Default facadeCost is $1,000/sqm.
NPV - Build Cost - Facade Cost - Profit
where Profit = Margin * NPV
margin is set in Giraffe appdata in the public.financial property. If it is not specified, it defaults to 20%.