Creating 4 window bays around Tower design (Caprian Monestary)


Hey guys,

So it’s been a while (2months gap) since I last used SketchUp, been busy with other things.

I seem to remember most methods, but that also include my usual clumsy inefficient methods too!

I started this model about 6months ago.

Im just looking for some advice really on how to go about creating what I’m trying to achieve.

Basically I have a tower design (rounded).

I’ve got a ‘column-archway’ design of which I need 4 (north east south west) around the tower.

Ideally there would be 6 but I’ve badly-modeled the size of the original tower… in short, im doing this from a 2d reference photo and just estimating the size of each tower (there;s 5 or 6 in all).

This is a bit of a chicken-egg situation you might say?
-if I choose to upscale the tower im working on, then the other towers I’ve already modeled have to upscale too. And 1 or 2 of those are connected by other gemoetry and it could all end up quite messy basically.

this is what i have so far…

And now, about the window(s) themselves.
To create what I have so far, you can see that the towers are all pretty similar. So I’ve obviously duplicated them to save remodeling etc, just adding little changes to each one where necessary.

So my basic tower template is a tall cylinder which various ridges and extensions plus a roof on top.
they’re hollow inside.

So to add this window area, I modeled the archway/columns/window area, dragged it on top of the tower (in correct place) and INTERSECT with model. I then was able to ERASE the middle area inside the columns/archway, create a flat panel (where there used to be the surface of round tower) and sketched the window design on top of it.

But that was definitely a laborious process.

The method has always been like this, just rotating/duping a group (eg the church cross motifs) around 90degrees etc. to get them in place.

But not until now have I needed to create windows around the cylinder.

So obviously I’ve needed to erase surfaces where the windows would go to slot in a window.

Hope im not over-explaining this, or stating the obvious!
I find when i’ve spent 6 hours modeling, my expression declines!

So that’s been my method.
going forward, I’d rather not have to do all that intersect, erase etc. etc. again

can anyone recommend a good or quicker approach?

many kind regards.


If all the towers have four-, six- or eight-way symmetry (identical segments) you could make one segment into a component, make your intersections once only, then copy/rotate round the central vertical axis enough times to get the whole circular part of the tower. You would probably need to hide the edges and delete the faces at the joins.

Are you making components as you draw parts of the geometry? If not, you are making things too connected and hard to edit.

After making one tower into a component (I hope), and scaling it, did you make each one unique? If so, re-scaling one won’t change the others.

And I rarely find it useful to make groups, which are only a simpler form of component. There’s almost NO reason to make groups, instead of components, except if (a) there’s only one in the model, and (b) you don’t want to clutter up the Component Browser with components you never intend to use more than one of.

Make (or remake if you need to) your ‘columns, arch, slope and window’ group into a component, or better, a composite of mirrored half-components, so you can take advantage of symmetry.

And indeed, make a column as one component, half the arch top another component, and the slope and middle either into two half components, or a third full component. Mirror the columns and arch top, to get a full set of elements, then make all into one combined component. Though (I now realise) that may make using Intersect Faces more complex. You would have to explode the subcomponents before using it, or else do the intersection one subcomponent at a time.

Can you upload the model so far, for the possibility of more detailed and constructive comment? If it is too big to upload directly to the forum (>3MB) try uploading it to Dropbox, the 3Dwarehouse, or another file sharing site, and provide a link to enable others to download it.

PS. Forgot to say - it’s a beautiful building to be modelling, and a challenging one for SU. Good going so far!


Thanks for such a detailed response!
I got a bit confused with the suggestions, but I will give it a proper read again soon, I’m sure it all made sense, I was just a bit busy at the time.

Generally speaking, I am heeding the advice and using groups and components logically.
But in my early days making this model, I wasn’t , so all those early parts are still a bit tangled up and connected (with various silly little hovering lines I’d added as extras, to mask over a gap for example). – and those silly individual lines would have been just drawn any old place, whether in a group, or not! — so then stretching the main bulk of a tower to scale it up… im leaving all these little niggly bits behind and it’s just messy.

I know what I’m doing now in terms of components and groups,I’ve learned my lesson.

I understood what you said about getting one segment done, rotating it around a centre a number of times to create 4,6,8 segments. And that’s what I’ll do. But for now, I’m trying to build out a part of the segment and having a new problem.

I’m trying to create what you can see on the right side of the picture:
The ‘shelf’ of the window area “1” only ever came down as far as being in line with the extent of the pillar/columns… I coldn’t think of how to extend it? so I drew a continuing line (along the surface of the slope) out into the ether and then just drew lines left and right off of that, to create the extent of the new slope bit “2”. It was painful and probably not the best way of doing it.

Because i also then had to draw those angled lines you see coming up from the ends of that front line, up to the back of the pillar bit. really cack-handed.

Doing it manally this way seems to have created a problem for me now that I’ve come to adding a ‘follow me’ profile shape at the edge (as you can see in the pic). —it doesn’t follow-me correctly around the entire edge, and I think it’s because there are multiple ‘silly’ ‘fix-it’ lines which I’ve added to try and make this shape manually.

Long story short, if I created that entire bank piece (bits 1 and 2) in a single shelf shape obviously it would follow around the edge perfectly. -but I just didn’t approach it correctly.

Would anyone mind taking a look at the skp file and see what I could do different?

kind regards.setup.skp (855.2 KB)


One of my favorite quotes is by Henry Ford, who said “Failure is an opportunity to begin again more intelligently”.
I’d recommend you take what you have and use that to convert everything to groups and components. Taking care to make things symmetrical a to even dimensions where possible. You may not need as much intersecting as you think.
Take a look at the re do using your model.
Some time ago I started a group of townhouses the third time before I got what I was looking for.
Don’t be discouraged, just keep sketching.
arch window shep.skp (1.0 MB)



#1 Do not get “stove piped” aka stuck on one idea, consider drawing the surface and the " box" joint and just push them in the appropriate distance;
#2 There are many issues with that model you should spend time correcting before going further or even start over. I found one group and one component( Lisa). Quit using groups and max use of components. A model this complex I would anticipate you will use 10 to 20?;
#3 Get rid of all the stray lines I found 21 of them. You can remove them all in one step by using the stray line plugin;
Some of the correction will probably break model in areas you will have to correct;
#4 ThomThom hsa a clean up plugin you should consider using. Continuing forward with out correction errors will just exponentially get worse


I second that - errors compound. Better to go back and redraw cleanly using components, than to try to continue using the equivalent of shaky foundations for a building.


I’ve just run the CleanUp3 plugin on your model of one arch.

It reported:

Cleanup Statistics:
Edges Reduced: 3232
Faces Reduced: 12
Hidden Entities Erased: 1
Skipped Locked Definitions: 0
Total Elapsed Time: 1m 10s

Where did all those redundant edges come from?

And you have a few reversed faces. They show in blue-grey in the left hand arch

The right hand arch still has some loose geometry - showing as selected in the image below. Make it a component, and make all the groups in your model into components too.

It’s going to be a lovely model when done. And a fine original building to be modelling.

Thank you for showing it ‘in progress’.

PS. In case it might be of use, here’s the cleaned up model. But I haven’t changed the group or component structure.
arch window shep (1).skp (1.1 MB)


There is a multitude of model errors and that in combination of the use of the fractional units display resolution is not accurate enough and leads to a major source of those to the extent I doubt the model is repairable in a reasonable time. Look where the actual columns intersect with the vertical walls. The OP has chosen to intersect at a very high slope point which makes it very difficult. The sloped over hang back toward vertical wall is not one a reasonable designer would do IMHO. They are misplaced by the OP and will continue to facilitate errors.
Suggestion : Move the col. back so they intersect at point like the actual design: Get rid of the fractional display and use at least 3 digit decimal: neutral_face; make use of symmetry to reduce model effort: make max. use of components…
Good Luck!


Thank you for trying to fix my model issue. I’m sorry I forgot to say thanks!
I tried to use it, but unfortunately I’m still using 2016 and your work was done in 2017. But thank you anyway! (I should probably upgrade!)


Thanks for the tips. I’ve started using groups and components a hell of a lot more now.

Regarding moving the columns back (as you suggested), on some of the towers, the columns are further back, on some they aren’t.


One more thing I’d like to ask. If I change the fractional display, and go instead to using 3dig decimal as you suggest, would that mess up any modeling done so far or are you simply just changing the value?

Here’s how it currently stands, I seem to be at 6 digit decimal?

Lastly, I’d like to show everyone what I’ve made so far, I know there’s a lot of problems with it, but I’ve put a lot of hours in and took advantage of to add a few effects:

Caprian Monestary WIP on SketchFab


All the model units setting does is alter the format by which values are displayed. It does nothing to the actual values stored in the model.


ok thanks.

Just so I have this right; if I have 6 digits after the decimal point, I’m basically on ‘6-digit’ right?

So this is MORE accurate than 3? I would presume so.


Not more accurate. The displayed dimension is more precise. It doesn’t make your model more accurate when using higher precision. It makes it easier for you to see specific dimensions and slight differences between them. Keep in mind that a human hair is on average about 0.004 inches thick. Showing dimensions to six places right of the decimal in your model is fine and in some cases useful but the thing you are modeling wasn’t built with anywhere close to that precision. That does not mean it isn’t accurate, though.

Using fractional units isn’t a problem, either. At best it will show your dimensions to the nearest 64th of an inch. 1/64 is 0.015625 in.

As @slbaumgartner wrote, Precision only determines how precisely dimensions are displayed to you. The setting makes no difference to the program.


This topic was automatically closed 91 days after the last reply. New replies are no longer allowed.