New Look

The blog needed a refresh. Hope you like it, its still work-in-progress, so the images & layout might yet still change.

Curtain Wall icon – speed green - 2014

Was testing some Revit 2014 things today & suddenly my Curtain Wall icon went funny? Not sure why, but after a restart it sorted itself out. I do find if you do get these sort of glitches in graphics, a restart typically solves the problem. Neither less, it was a surprise & colourful addition to the Revit 2014 interface!

PAS1192-2: new BIM standards - NBS TV video

The NBS have produced a useful video which explains BIM in the UK, especially around the COBie, PAS1192-2, RIBA BIM overlay requirements. It makes interesting viewing, with interviews with Nick Nesbit (BuildingSMART UK), John Eynon (architect) as well as Dale Sinclair (Dyer). The interviewer does an excellent job at questioning the interviewees, pushing them to demystify the whole thing. I found it slightly amusing that technology seemed to get side stepped, but then remember I am a technology geek. This is what fires me up. Whilst people & process along with collaborative working are essential to BIM, I like to understand how the technology integrates with the process to drive efficiencies at a fundamental level for collaborative benefits.

Do I believe the UK will be ready for the 2016 BIM requirement? Nope, sadly I don’t. It’s going in the right direction with a massive push & it’s refreshing that the discussion is being had. There is also some great Project work already being done or completed using a BIM methodology. HOK’s BP2, Barts Royal London hospital or Crossrail, Francis Crick to name but a few. The big game changer is the data requirements.

But right now I still see many that are confused by much of the new generation BIM requirements, if you can call it new generation. This is not me being negative at all, it’s just what I observe day to day. When you still have people concerned about the quality of the drawing output from say (insert preferred BIM authoring application), then there is no way they are ready for this next step. There is so much to learn & a fundamental mind shift required.

I hope I am proven wrong, I really do. But with so much going on, so many new terms, so many acronyms I wonder the average construction individual is confused. Our industry is complex enough as it is, please let’s not make it even more confusing. Feel free to challenge me if you think I am wrong, but when I speak to other likeminded experts, whilst they are not necessarily speaking out, secretly they have some reservations as well. It’s just that I’m stupid enough to say it publically.

PAS1192-2: new BIM standards - NBS TV video

Auditing Walls

After my recent blog post about Location Line consistency, Luke Johnson asked…..

“Dave, when auditing a project (and trying to fix inconsistent location lines), do you have any tips on the most reliable way to do this?
If a wall is oriented incorrectly and needs to be flipped, do you recommend switching to 'Wall Centreline' and then using the flip control?”

When you audit a file you can’t schedule the wall Location line which is an annoyance. The only obvious way is to select the wall & observe the constraint set in the properties palette then change it. Like you are going to go through each wall in your project one by one???!!! It’s just not going to happen.

However, this parameter is exposed via the API. So once again CASE Exceler8 comes to the rescue!

If you export all your walls from your project via Exceler8 you will see the Location Line parameter listed in the resulting Excel workbook for every wall. However, it does not provide you with the actually location name, instead it’s defined as a number from 0 to 5. The values equate to the following:-

• Wall Centerline = 0
• Core Centerline = 1
• Finish Face: Exterior = 2
• Finish Face: Interior = 3
• Core Face: Exterior = 4
• Core Face: Interior = 5

Therefore, even though this is not visible in the project, you can start to review the data in Excel & with some filtering of headings, you can isolate which walls have which location lines. With an appropriate strategy & the fact you now have the element ID of the walls you can tweak the walls in Revit. Or if you are feeling adventurous, change the parameter value in the Excel workbook for any walls which you think “might” cause problems & then drive the updated data back into the model using Exceler8. In this simple video example, I have 10 walls, with differing Location Lines set. For each wall, as a double check I have included a comment of the location in the comment parameter. I export using Exceler8, review the changes, tweak the Location Line, back to Finish Face: Exterior, value 2. Then update the walls, by sync’in the data back into Revit. Job done.

 

Be Consistent – Wall Location Line:

This is going to seem an obvious, but being consistent with the management of the wall Location Line constraint is essential when laying out walls in your project. When I dig around users projects, I often find inconsistent strategies, which “can” lead to issues with wall joins. You can set the wall location line parameter when you first place a wall, this is available from options bar.

 

New users often don’t know what all these different parameters are or what they even do. They merrily go away & place walls with different Location Lines set, only to find that walls are not cleaning up as expected. Let me show what each of these parameters are referring when you place a wall. The diagram below shows what each parameter alignment does.

The Core boundary is set in the wall type itself. All wall system families have a core Boundary, internal & external. Observe that its the “green” lines in the screen grab above.

Now whilst this might be a slight sweeping statement, but I advice users to be as consistent as they can. If you are placing your external facade walls, typically ensure they are all set to the same location line. Also, watch the location you choose. If you choose Wall Centreline & you have to flip the direction of the wall, there are no differences, as you are mirroring the wall around its centre line, on which you placed it. If on the other hand you choose Finish Face: Exterior, when you flip the wall, you are flipping the whole wall width, this can impact areas, so be mindful of this.But if you have to change the wall makeup, then Finish Face: Interior may be preferable as you might not want to impact areas within the building.

“Ok!'” What do you recommend then? To play safe, I either make all my external walls be Finish Face: Exterior or Finish Face Interior. What I choose very much depends on the project stage & whether I know the wall build up. As for internal walls, I try very hard to always make internal partition be wall centreline. This strategy has worked for me, I hope you have similar success. But do remember you can change the wall Location Line at any time if you need to, by selecting the wall & changing the Location Line parameter from the properties dialogue box.

Shared Coordinates

Shared coordinates seems to be one of those subject areas which causes a mental block. Not actually sure why, but it does. I know others including Steve Stafford having documented & shared this with people time & time again. I even posted something a few years back which defined the process. Anyway, this is my quick step guide to setting up shared coordinates by “specifying a coordinate” at a point. I am 100% confident with this process, a bold statement I know, but I have helped setup some mega projects using these steps & it works every time for me.

Start by opening the survey drawing in AutoCAD; as good practise check the unit of the DWG, this is achieved by select or typing “DDUNITS”. It’s also worth Auditing the DWG for any errors using the “AUDIT” command in AutoCAD. Next using the “ID” command, ID a point, this may be a benchmark or a survey pin on the survey plan. In the example below, it is an Easting & Northing of 100000,100000, with the units of the DWG set to millimetres.

In Revit, start a new project. Next go to the Site view & notice the Survey Base Point & the Project Base Point. Do not move them right now.

Next import the DWG survey, but it is essential to import “centre to centre”. Do this by going to the Insert tab > link CAD this will open up the Import CAD dialogue. Locate the DWG & ensure the units are set & that you are importing centre to centre.

Once you have everything setup, click the Open button & the DWG will be imported. If you zoom all, you should see the DWG imported & the elevation symbols, very small. Resolve this by changing the scale of the view. If for any reason the DWG is not imported centre to centre, you need to go back into AutoCAD & check the DWG file as there may be an ordinate dimensions setup which can mess with the result. Remove the ordinate dimensions from the CAD file & go back a step to import again.

Next we need to align the coordinate system of Revit with the imported DWG file. Start by upclipping both the Survey Base Point & the Project Base Point.

Next we will move them to a location of 100000,100000 which is on the bottom left hand corner of the DWG. You may want to put the view into thin line mode to help with the line weights, as this can be distracting. Ignore the Northings & Eastings, we will resolve this in a moment. Place the Survey Base Point as below. Do NOT clip the Survey Base Point yet.

Next go to the Manage tab & the Coordinates. Choose the Specify Coordinates at Point command.

Pick the intersection. If this is problematic, draw a model line from the intersection & pick the end of the line where it intersects with the DWG.

In the Specify Shared Coordinates, type in the Northing & Easting to match the DWG file. You may also want to address the elevation level if you know this.

Once you have done this, click OK, to set the shared coordinates. Select the Survey Base Point & now click the paper clip, this will lock the Survey Base Point in place.

With the Project Base Point still unclipped you can then move this either to the Survey Point or to another reference location on the linked CAD file, if you know another survey coordinate or even a grid intersection, place it there. Once you have chosen a suitable location, clip the Project Base Point.

So as a double check, its good practice to save the file & then export the survey view as a DWG by shared coordinates back to CAD to see if everything has been setup correctly. To do this, go to Application Menu, big R>Export>CAD Formats> DWG files

This will open the export DWG dialogue; next go to button with 3 dots which is the Modify Export Setup.

Go to Units & Coordinates & ensure the Coordinate system basis is set to Shared. Select OK.

This will return you to the export dialogue, choose Next.

Name the export ; then Export the DWG to a suitable location. Ensure Export views & sheet links as external references is NOT ticked.

Next open the resulting DWG in AutoCAD. Use the ID command to double check the coordinates have been passed back correctly.

In this example we have zoomed into the location of the Survey base point & used ID in AutoCAD to check the coordinates. We can see from the example that they are spot on in the resulting DWG export.

As an extra check, you can always Xref in the original Survey CAD plan. If they drop in correctly on top of one another, you can be confident that the shared coordinates between AutoCAD & anything you export from Revit are correct.