How to prevent your ARCHICAD model from becoming detached from Sea Level.

The relevance of Project Zero, Sea Level / Altitude / AHD, Reference Levels & Home Story Settings

Looking at how to get a building to relate to sea level in ARCHICAD is an interesting topic for discussion and in my opinion has been prone to interpretation. I have had many a debate with other ARCHICAD users over these past few years regarding the “correct” way to use it. My take on the subject is that I use it the way GRAPHISOFT intended it to be used. A big game changer was one of the new features of ARCHICAD 16.

Better Project Location/Project North Definition > Define a Project Altitude relative to Project North; optionally use the Altitude value as a fixed Reference Level in Project Preferences, available in all dialogues that refer to a Reference Level

The relevance of this is that the field “Altitude” found in Project Preferences > Project Location sets the “Elevation” field for “Sea Level” found in Project Preferences > Reference Levels. In other words, they are directly correlated.

Project Location to Project Preferences.png

The most important part to note is that the actual elevation values of any model elements are always calculated from Project Zero and that reference levels are for display and input aids. Another way to put it is Project Zero never moves up or down; it is a fixed reference point. Changing the value Altitude (Sea Level) does not affect Project Zero. In other words, the building related to Project Zero does not move, but Sea Level does.

project zero & sea level

Let us look at the term or definition of “Project Zero” before continuing.
When teaching ARCHICAD to new users, I like to explain that Project Zero = Reduced Level in surveying terms.

In other words, Project Zero is the adopted datum plane for the start of the building model; it is horizontal and commonly assigned to the top elevation of the Ground Floor slab, placed on Story No. 0 – Ground Floor (street level).project zero - GF

For those American readers of this blog, I would like to point out that the localized version of ARCHICAD USA; Story settings start with story No. 1 – 1st Floor. It is of course due to the difference in British and American English: the naming of floors in buildings.

In British English, the floor of a building at street level is called the ground floor. The floor above it is the first floor, and the floor below is known as the basement.

In American English, however, the floor at street level is usually called the first floor. Go up one floor and you are on the second floor (which, of course, is the first floor for the British). The floor below street level is called the basement, the same as in British English.

In other words for America, Project Zero is assigned to story No. 1 – 1st Floor (street level).

ARCHICAD USA Story Settings

Just to reiterate the use of “Altitude” has been with us since it was introduced in ARCHICAD 16. Which was announced on May 2, 2012, more than 4 years ago

A functionality improvement for ARCHICAD 19, was the inclusion of “Altitude (Sea Level).” My thanks go out to James Badcock, who is a Product Designer at GRAPHISOFT HQ, who advised me that he was responsible for putting in the request to the Product Team to insert the words “Sea Level” after Altitude.

Altitude (Sea Level)

Reference Levels Preferences

Note: You cannot rename the Project Zero or Altitude reference levels.
Note: Reference Levels are display and input aids only. Changing their value has no effect on placed elements, whose actual elevation is always calculated from Project Zero. The exception is Grid lines in Section view, whose position changes with the Reference Level.

But you can rename the 2 provided Reference Levels and change their Elevation value. This is especially useful when working on a building that has split levels.

Project preferences 1st Ref

Reference levels can also be used as reference levels for showing elevation (Z) values in the Tracker. When entering a distance using Tracker, keep pushing Tab to get to Z Coordinate and click on the small arrow to show “Elevation Value Origin”.



What does this mean for the user, and how did GRAPHISOFT envisage that it should be used? The answer lies in the simple fact that when looking at Story Settings, there is no need to insert any value into Story Settings to get the model to relate to Sea Level.

Looking at it from an Australian perspective and the use of AHD or Australian Height Datum. According to:

Wikipedia – Australian Height Datum

The Australian Height Datum is a geodetic datum for altitude measurement in Australia. According to Geoscience Australia, “In 1971 the mean sea level for 1966-1968 was assigned the value of 0.000m on the Australian Height Datum at thirty tide gauges around the coast of the Australian continent. The resulting datum surface, with minor modifications in two metropolitan areas, has been termed the Australian Height Datum (AHD) and was adopted by the National Mapping Council as the datum to which all vertical control for mapping (and other surveying functions) is to be referred.

It is my opinion that “Australian Height Datum” or AHD for short is just another way to say “sea level”. And that in ARCHICAD, the use of the value field for “Altitude (Sea Level) is the same as AHD as it was assigned the value of 0.000m.

The use of “Story Settings” in ARCHICAD INT is to represent the logical story structure of the building starting with story 0 = Ground Floor = Project Zero. Then Story 1 = First Floor, Story 2 = Second Floor etc. Therefore when looking at Story Level Lines, they follow the same logical progression. Inserting a story below Story 0, results in Story -1 which can be used for Basement / footings / foundation.

-1 Basement story setting.png

Looking back, to before “Altitude” was introduced in ARCHICAD 16, namely versions 15, 14, 13, etc. there was still one of the two Reference levels (1st or 2nd) that could be substituted and renamed to AHD or Sea Level.

AC15 Levels & Project North.png

ARCHICON / RTC Hunter Valley 2016


I am very excited to have been asked to present one of my favourite features, namely CineRender in ARCHICAD at this years ARCHICON / RTC Hunter Valley 2016. The event is to be held 12-13th May 2016, with RTC Australasia running a day longer. For more information and to Register click here!

The focus of my presentation will be to highlight how ARCHICAD provides enhanced, more realistic rendering capabilities out of the box! In practice, this means, that anyone can create state-of the art, professionally rendered visualizations of their projects without the need to buy, install and learn any additional software applications!

For example one of the topics I talk about will be Surfaces, and how Cinema 4D Textures capabilities were integrated into ARCHICAD. Including an expose of Textures / Channels / Procedural Shaders etc.

Then there will be an opportunity to showcase the fact that the CineRender engine was updated. Here is the details as per the GRAPHISOFT ARCHICAD 20 announcement that was made yesterday the 3rd May 2016:

ARCHICAD 20 runs the latest CineRender version, based on the Cinema 4D R16 engine. The result is a major enhancement concerning surface settings.

This ensures even more realistic surfaces, while rendering improvements reduce render times and enable highly-realistic contact shadows.

A new Reflectance Channel allows multiple reflection layers and control over blurriness and distance dim. Perfect for architectural materials like metals. A “turbo boost” to render times is possible thanks to the Irradiance Cache and the Physical Renderer, which features a new ray-tracing solution and faster grass calculation.

I look forward to seeing all those attending ARCHICON 2016. Including the opportunity to be there to participate and learn from the other Presenters.

Gideon Taljaard is the ARCHICAD Manager at Plus Architecture. Plus Architecture is an award-winning, integrated architecture and interior design practice founded in 1997. With offices in Melbourne, Sydney, Brisbane and New Zealand, its capabilities extend to multi-residential, master-planned, commercial, aged care and mixed use developments.

Gideon’s previous experience saw him working for the ARCHICAD reseller in South Africa from 2000 to 2012, and from 2013 to 2015 for the ARCHICAD reseller in Australia. He has 20 years’ experience using ARCHICAD starting with ARCHICAD 4.5.

Corner Windows (Butt Joint Glazed) – What happened to “Ribbon Window 17”?

Corner Window Banner

I was recently asked to update an older article I posted ‘HOW TO: BUTT JOINTED GLASS WINDOWS IN ARCHICAD’.

The request was, “Gideon Any chance you could update this for version 18 onward? The ribbon window is no longer standard in the libraries…”

The good news is that it is still possible to achieve this. So for the release of ARCHICAD 18, GRAPHISOFT advised us that they had made Window Improvements. This included two New Multi-Sash Windows, namely:

  • Horizontal Multi-Sash Window
  • Vertical Multi-Sash Window

Horizontal Multi-Sash Window 18

So basically the “Horizontal Multi-Sash Window” has replaced the Ribbon Window. It has the same option “Custom Corner”.

Custom Corner

And under the option ‘Corner Connection Type’ there is the option for ‘Glass’.

Corner Connection Type

Then just to point out the position of the button for ‘Custom Corner…’ in ARCHICAD 19 with the new overhauled Graphical Interface for the controls of Door / Window Settings.

ARCHICAD 19 Horizontal Multi-Sash Window 19

Note: the ‘Vertical Multi-Sash Window’ does not have the option for Custom Corner > Corner Connection Type = Glass. But it is possible to create a ‘Vertical’ looking butt jointed glass window using Horizontal Multi-Sash Window.

H-V GridVertical divisions

ArchiCAD 17 INT New Feature – “BIM pen sets” by Material

The assigning of pens to an element for the  ArchiCAD INT version has been around for some time. In fact it was introduced in ArchiCAD 10 INT for the very first time. ArchiCAD 10 was released in 2006, so it has been with us for 7 years with very minor changes in its workflow.

ArchiCAD 9 INT to ArchiCAD 10 INT

That was until the release of ArchiCAD 17 INT and the introduction of “assigning pens to a material”. This functionality change of course was due to the introduction of “Building Materials…”.

“A Building Material is a “super attribute”, a combination of multiple attributes having defined properties. Starting with ArchiCAD 17, all model elements use Building Materials instead of Cut Fills.” The most important part about this statement would be the part I highlighted in bold.

I am trying to seek simplicity in emphasizing this. Previously model elements had a cross sectional representational Cut Fill, but this has been replaced by skins of composite structures. Each skin of a composite structures are assigned with their own building material, and building materials have their own surface definitions.

This means that “Composites…” in ArchiCAD are no longer represented by 2D fills but are in fact “solid” which is now evident in both 2D plan, elevations/ sections and of course 3D. This change in functionality has brought about a change in how pens are assigned to both Building materials & Composites in ArchiCAD 17. We now have Pen Index Number Assigned by ‘Material’ in addition to Pen Index Number Assigned by Element.

Pen Index Number Assigned by 'Material'

The strangest thing is there does not appear to be any documentation or reference to this change in functionality by GRAPHISOFT. The only reference I could find is to the subject of ‘Pen Sets”, the new Help Center refers to Pen Sets with its related subtopics. But I could not find any reference to Pen Index Number Assigned by ‘Material’. So herewith my explanation for:

ArchiCAD 17 New Features – Pen Index Number Assigned by ‘Material’.

ArchiCAD 17 - 03 Architectural 100

Changing the Pen Set from ’03 Architectural 100′ to ’04 Building plans 50.

ArchiCAD 17 - 04 Building plans 50

For more information on Pen Index Number Assigned by Element in ArchiCAD, please refer to the ARCHICAD WIKI article > Pen Sets

I don’t want to appear to be “reinventing the wheel” when looking at this subject. The easiest way that I can think of describing how Pen Index Number Assigned by Element works, is to change the way you look at the pen table. That is to say “look at it sideways” (by column) instead of horizontal (by row). Each column represents an element in ArchiCAD. And the most important thing to note is don’t change the pen position to change its Pen Weight, but change the Pen Set. Changing the pen set re-assigns the Pen Weight to the Pen Position.

For example, walls are assigned a default cut line pen with index 27 (column 07 Walls / Curtain Walls, which corresponds to the function “Walls – Cut Structural.”

Pen 27 (column - 07 Walls : Curtain Walls = Walls - Cut Structural

But maybe a little “history” will not hurt.

ArchiCAD 9

255 Pens with Pen Weight assigned to each but no description

ArchiCAD 9 Pens & Colors

ArchiCAD 10 New Feature – Named Pen Sets

In ArchiCAD 10, named Pen Sets are available as a new feature, and the matrix “Pen Index  Number Assigned by Element is introduced. All Pen Sets have 255 pens which are arranged in 20 columns and 14 rows.

ArchiCAD 10 Pens and Colors

ArchiCAD 11 New Feature – Pen Sets in Views

Pen Sets are assigned to the views (as a result model views will be WYSYWYG). Pen Set selection is available from View Settings and can be varied for placed drawings in Drawing Settings. Pen Sets can be edited directly from Drawing Settings.

ArchiCAD 11 New Feature - Pen Sets in Views

ArchiCAD 11 to ArchiCAD 16 Pens & Colors (Model views) functionality:

ArchiCAD 16 - 03 Architectural 100

Changing the Pen Set from ’03 Architectural 100′ to ’04 Building plans 50

ArchiCAD 16 - 04 Building plans 50

Last but not least, to better understand ArchiCAD 17 New Features – Pen Index Number Assigned by ‘Material’ I produced the following table from ArchiCAD that I saved in PDF format for printing out to A3 for reference purposes.

AC17 Pen Sets

Bon Voyage! User Group Meeting this Monday


Join me, this coming Monday! For a Bon Voyage User Group Meeting. The subject that we will be covering will be the use of EcoDesigner & Green Building Design Analysis.

ArchiCAD Usergroup Meeting, limited to SSA clients only

Venue: GRAPHISOFT SA Office, 500 Esther Roberts Road (formerly Frere), Glenwood, Durban.

Monday, 29 October 2012, 2pm – 4pm

face to face training, booking essential, send booking request here

How to: Butt Jointed Glass Windows in ArchiCAD

I recently received an e-mail requesting help to make a corner window with butt jointed glass. This has been possible since ArchiCAD 14 but apparently not all users are aware of this.

Go to the Corner-Window tool and open up the “Corner-Window Settings” dialogue. Select “Ribbon Window 16” from the Special Windows 16 Folder. Then from the “Special Windows Settings” tab enable the tick for “Custom Corner Right”, and in the drop down change the option to “Glass”. Then set all the other parameters for the size, frame, materials, sill etc… Click “OK” to close the window.

Now click on the wall close to the corner (but not on the corner), this will generate the corner window to both adjoining walls.

As seen in the 3D Window.

Another example is the requirement for a curved wall with segmented butt jointed glass window.

Please note: one needs to establish the angle between the walls.

Insert this into both “Custom Corner Left” & “Custom Corner Right”.

As seen in the 3D Window