Capturing Historic Architectural Detail in SketchUp

In the very first Connecticut houses, architectural detail was minimalistic and strictly utilitarian. But even the earliest colonists wanted their homes to look good, so in time, both interior and exterior detailing began to take hold. Much of this elaboration incorporated both Classical and Jacobean forms. And even prior to the middle of the eighteenth century, arriving English carpenters had begun infusing colonial architecture with the prevailing nuances of Georgian England, and the teachings of Christopher Wren.

Historic detailing in the front entry of the Curtis House, Stratford, Connecticut.

A beautiful example of exterior architectural detailing surrounds the front entry of the Edward Curtis House (c. 1745) of Stratford, Connecticut. It features fluted pilasters supporting a cornice with a dentil band. Carved Tudor (6-petaled) roses decorate their capitals. The very thick lights at the top of the paneled doors are known as "bulls eye" glass, and are also found in the front door of the nearby Judson House.

Colonial carpenters sometimes added their own unique flourishes, and often you’ll find variations of the same basic architectural theme in different locations. For example, the fireplace paneling in the parlor chamber of the Rev. Richard Mansfield House (c. 1700), about fifteen miles away in Ansonia, Connecticut, includes elements nearly identical to those detailing the entrance of the Curtis home:

Fireplace paneling of the Mansfield House parlor chamber with pilasters and Tudor Roses.

The fireplace paneling of the Mansfield House parlor chamber likewise features fluted pilasters, Tudor Roses, and breaks in the upper bed molding similar to the Curtis home entrance. The central composition of panels, rails, and stiles, situated between two pilasters as it is, is reminiscent of paneled doors. Whether this was done intentionally, or not, is probably impossible to say.

In recent times, I’ve become obsessed with colonial architectural detail, and its evolution within the Connecticut and New Haven colonies, and their surrounding regions. In particular, I’m determined to capture as many surviving examples as possible, both in photographs, as well as in three dimensional models drawn using Trimble SketchUp. I’d also like to establish an online archive of architectural models unique to our region.

To this end, I’ve selected another example from the Mansfield House for an initial survey project — the fireplace paneling of the hall chamber, which is rather nicely executed, but also sufficiently straight-forward to make for a reasonable first attempt:

Mansfield house hall chamber fireplace paneling.

Fireplace paneling of the Mansfield House hall chamber.

As often was the case in early Connecticut homes, the fireplace paneling here is integrated with the chimney girt and rear post, stylistically “supporting” the girt as a simple cornice or entablature, via a bed molding. This particular fireplace paneling sports a number of interesting architectural features, including this rather elaborately built-up mantel shelf:

Mantel shelf of the Mansfield House hall chamber fireplace.

Mantel shelf.

Also of interest is the heavy bolection (sometimes called Italian) molding surrounding the fireplace opening, while the panels themselves are beveled, and rabbeted into beaded rails and stiles:

Bolection molding surround the fireplace opening of the Mansfield House hall chamber.

Heavy bolection molding and raised, beveled panels.

So, to start off as simply as possible, I decided to initially model the bed molding beneath the chimney girt (excluding, just for now, the small cove supporting it), which is of classical cyma recta contour, and includes a mitered return at the end opposite the post:

Cyma recta bed molding supporting the cased chimney girt.

Cyma recta bed molding "supporting" the cased chimney girt.

The other end of the molding terminates flat against the rear post’s casing:

Cyma recta bed molding of the Mansfield House hall chamber fireplace.

Left end of the bed molding.

I collected contours from three different locations along the bed molding (all were slightly different), and standardized on what I’d hoped was a reasonable interpretation, on my part, of what the original craftsman had intended:

View of the cyma recta molding profile.

A head-on view of the profile of the bed molding, revealing its slightly distorted shape.

I did so using a standard contour gauge:

Contour gauge and notebook.

My contour gauge and notebook.

And transferred them as best I could to my engineering notebook. I also measured and recorded all of the lineal dimensions of the molding as accurately as I could (a pair of very long dividers comes in handy when measuring irregularly shaped or obstructed features):

Page of my engineering notebook with captured contours and dimensions.

Some of the contours and dimensions captured in my notes.

Once I felt reasonably confident in my measurements, I set about building an initial SketchUp model of the molding, by first drawing the rectilinear segments of the molding contour in two dimensions, and adding guidelines corresponding to the vertical graph lines of my notebook:

Initial SketchUp model of molding in two dimensions, with guidelines.

Initial model in two dimensions: Rectilinear profile segments and guidelines.

Next, I added horizontal guidelines corresponding to the points where my captured cyma recta curve intersected with the vertical lines. I then used the SketchUp arc drawing tool to fit as smooth a curve as possible between these intersections:

Initial model in two dimensions: Horizontal guidelines added.

Initial model in two dimensions: Horizontal guidelines delineating cyma recta contour intersections with the vertical guidelines.

The final, two-dimensional representation of the contour looked like this:

Two-dimensional model: Molding contour.

Initial model in two dimensions: Molding profile.

Using SketchUp’s pull tool, I then extruded the two-dimensional contour upward along the third dimension:

Initial model in three dimensions: The molding contour extruded upward.

Initial model in three dimensions, with the molding contour extruded upwards. The vertical lines are a side effect of how SketchUp manages curved surfaces, and are easy enough to hide.

Then, I “flipped over” and rotated this three dimensional shape so as to properly align it with the standard axes defined by SketchUp. Doing this ensures that modeled components are correctly oriented when combined together to build more complex models. I also lengthened it a bit. Here’s what the resulting molding section looked like:

Cyma recta bed molding section in three dimensions.

Cyma recta bed molding section in three dimensions.

Now that a basic molding section had been created, my next big step was to figure out how to miter either end. Unlike real molding, I couldn’t take a double-bevel compound miter saw and simply cut it — that would’ve be too easy! Instead, I had to figure out how to “cut” a 45 degree miter in SketchUp. SketchUp is a bit rigorous about what you can and can’t do when altering irregular shapes. Admittedly, I had to try this a few times before I finally got it right. What follows are screen shots of the steps I performed, in the event this is useful to others attempting to do the same thing (if you’re not, feel free to skip over the impending tedium).

The first step was to rotate the molding section so as to view its back side, and draw a 45 degree guideline across its top:

Molding section with 45 degree miter line.

Molding section with 45 degree guideline.

Then, I “scored” a vertical line down the backside of the molding section, beginning at the miter line:

Vertical line drawn from miter line down.

Vertical line drawn from miter line down.

Next, I selected the near vertical edge, and, making sure that nothing else in the model was also selected, attached the SketchUp move tool to the top corner of that vertical edge, and “swung” this vertical edge over to meet the miter line. The end result looked like this:

Result of moving the closes vertical edge to the miter line.

Result of moving the near vertical edge to the miter line.

The resulting white appendage seen above is the projection of the other side of the contour into the three-dimensional solid, and it now needed to be carefully removed by “intersecting” it with the remaining solid, and then “subtracting” it away. To accomplish this, I first drew a solid line along the bottom edge of the white geometry:

Drawing a solid line.

Solid line drawn along bottom edge.

Then, using ctrl-left-click, successively selected each of the curved contour sections (remember those vertical lines I needed to hide earlier, after I’d first pulled the two-dimensional contour upwards into the third dimension?). In the screen capture shown below, the top two or three contour sections have been selected (indicated by the slightly greyed-out areas):

Several selected contour sections.

Contour sections in the process of being selected.

Next, I used SketchUp’s intersect faces with model operation to effectively divide this section from the main model. Once this operation is actually performed, the curved line where the contour meets the mitered wall goes from transparent to solid:

Intersecting the faces of the contoured section with the rest of the model.

Intersecting the faces of the contoured section with the rest of the model.

Now that the model had effectively been divided, the unwanted portion needed to be deleted. To do this, I rotated the section back the other way, selected the main edges defining the separated contour, and then performed an erase operation:

Selecting and deleting the separated contour section.

Selecting and deleting the separated contour section.

The end result of this was a cyma recta section with a 45 degree mitered end:

Cyma recta section with mitered end.

Cyma recta section with mitered end. The final step is to erase the remaining guideline.

I then repeated the same steps in creating another molding section, but one with a 45 degree miter on the opposite end:

Cyma recta molding section with other end mitered.

Cyma recta molding section with other end mitered.

As a result, I now had both “left-hand” and “right-hand” mitered sections, saved as SketchUp components that I could readily import into a model and join together to form corners:

Corner formed by joining two oppositely mitered ends of molding sections

Corner formed by joining two oppositely mitered ends of molding sections.

Finally, by extending the non-mitered end of a “left-hand” section out to full length (in this case, 89-3/4″), and appropriately shortening a “right-hand” section to model the return, and then joining them together, I created an accurate model of the bed molding beneath the chimney girt in the Mansfield House’s hall chamber:

Mansfield House chimney girt bed molding.

View of the modeled bed molding from below.

This second view of the same model reveals more clearly how the return had been cut from a separate piece of wood, and simply joined to the mitered end of the main piece:

Mansfield house fireplace bed molding.

View of the modeled bed molding from above and behind.


There’s no doubt that modeling historic architectural detail in this manner is a lot of effort. But it’s time worth spent for anyone serious about capturing this information and making it readily accessible to others. The educational advantages of three-dimensional, digital models are significant: one can readily view, explore, rotate, and deconstruct such models to learn more about them. Also, if arbitrary two-dimensional plans or sections are desired, they can always be produced directly from the same three-dimensional model, without the need to create additional diagrams.

Furthermore, once a library of standard components has been established, new models can readily be created by piecing existing components together, and creating customized versions of those components wherever necessary. Models formulated using Trimble SketchUp can easily be published on the Internet via the Trimble 3D Warehouse. For example, both the left and right cyma recta sections I’ve created here may readily be downloaded from my own Trimble 3D Warehouse page. They can then be viewed using either Trimble SketchUp or Trimble SketchUp Viewer.

Finally, yet another advantage to publishing archives of models of historic artifacts online is that well-established SEO techniques can be leveraged to ensure that these model catalogs are found by those searching for them, while social media can likewise be used to publicize the existence of these archives to their intended audiences and communities.


This modeling exercise of mine was (very gently) criticized, recently, via Twitter, on the claim that there was no obvious, practical need for three-dimensional models of historic architectural millwork. While I don’t agree with that claim, I do understand the basis for it.

If I were creating a collection of SketchUp components representing well-known classical forms, or even standard millwork, then I’d happily concede that my critic had a point, as these forms are widely understood, and a great many examples of them have already been published in the SketchUp 3D Warehouse. But what I’m doing here is capturing the architectural details of specific historic buildings, and as such, I consider each modeled element to be fundamentally unique, even if it expresses some well-known shape.

For example, there’s nothing particularly profound (in a more general sense) about the model of the bed molding that I’d developed and illustrated through out the course of this article. But this small component will soon become part of a larger model of the entire paneled composition, which itself is quite unique, and of considerable historical significance. In that sense, even a trivial piece of molding needs to be accurately represented here. So I’m not inclined to search the 3D Warehouse for close equivalents, but rather model these pieces myself, and directly from my own measurements of their real world prototypes.

I should also point out that the models I’m constructing and publishing are primarily of regional historic interest. Some one researching the habits of early Connecticut carpenters might find them invaluable; but general architectural historians, perhaps somewhat less so (or maybe not). These are points I didn’t make completely clear earlier, especially in the above Summary, which seems to suggest more general intentions.

And finally, a secondary objective of the article itself is simply to share my own experiences using SketchUp with others who are undertaking similar efforts.


Here’s a photo of another cyma recta bed molding from the Mansfield House, this one from the hall fireplace. A small lower section missing from the return reveals that the molding is shaped from an angled board, as initially suggested in a comment posted by Jane Radocchia, and subsequently discussed by Sebastian Eggert:

Opened cyma recta bed molding from the hall fireplace of the Mansfield house.

Opened cyma recta bed molding from the hall fireplace of the Mansfield house. The small supporting cove also appears to have been shaped from a separate piece of wood.

This molding is of the same contour and dimensions as its counter part from the hall chamber, and I have no reason to believe them to have been constructed differently. So as soon as I’ve had a chance to measure the section, I’ll revise my earlier model to reflect this shape. And that same model will be used to represent either bed molding. So much thanks to both Jane and Sebastian for encouraging me to consider this.

Also of interest is the contour shown below, which was recorded by famed New Haven, Connecticut restoration architect and historian J. Frederick Kelly, on p. 192 of his “Early Domestic Architecture of Connecticut” (published in 1924). Kelly cited it as an example of a non-Classical contour that was indigenous to Connecticut, and often found in later period (Revolutionary to Greek Rival) compositions through out the state. So I’ll be keeping an eye out for this one in my travels, as well.

Indigenous Connecticut molding reported by J. Frederick Kelly.

About John Poole

My interests include historic homes, architectural preservation and restoration, improving the energy performance of old houses, and traditional timber frames.
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21 Responses to Capturing Historic Architectural Detail in SketchUp

  1. yehuditfish says:

    fasinating. i’d fancy this kind of house with a big fireplace like this.

  2. Daniel L. Bosques says:

    Very nice. Amazing that modern tech helps with ancient, beautiful craftsmanship. Well done!

    • John Poole says:

      Thanks, Dan!

      As you’ll soon learn all too well, I enjoy thoughtfully combining the best of the present day with the best of the past. I especially like the idea of bringing modern technology to bear on the particular problems facing historic and vintage structures, as long as it’s done in non-disruptive, non-destructive ways.

      ~ John

  3. A TERRIFIC article John. Very, very good work.

  4. Hi John;
    Excellent step by step. I’ve been trying as similar thing with Revit in the context of a school project, using it to create an as-is model of a historic local church. There is a steep learning curve, mostly due to the fact that if there are others are doing this sort of thing, they may be being proprietary about it. I have had to do some workarounds, such as going into Inventor to model the gothic arched mullions, but it’s really allowing me to stretch both my Revit skills and the rigor of my architectural surveying methods.

    Still very much a work in progress.

    • John Poole says:

      Hi Michael,

      Thanks very much for visiting and commenting.

      I’m generally familiar with AutoDesk/Revit/Inventor, and their application in building information modeling, but only to the extent that I’ve experimented with trial versions of the software, and never seriously. I think this is the first time anyone told me they were using those tools to model historic structures.

      I understand what you mean about the proprietary thing, which I feel, in the end, kind of defeats the purpose of doing this stuff in the first place. What I like about SketchUp is the spirit of sharing that seems to be fundamental to its culture/community. And this also is why I publish my designs with fairly liberal Creative Commons licensing wording attached to them, so as to make them maximally useful to others with similar interests and objectives.

      And your comment about stretching both your proficiency with the tools and the rigor of your surveying is painfully felt here, as well! There are many times when I find myself perplexed and even aggravated by what I’m trying to get SketchUp to do. But I usually figure it out with some persistence. And my appreciation for doing highly accurate survey work has also evolved considerably by undertaking a number of projects like these.

      Hope you decide to publish your project when it’s finally complete. If so, would love to see it; please keep us posted!

      ~ John

  5. Thank you for recording these moldings, and for the clear photographs. I think they will be a welcome resource for research and restoration just as the White Pine Series is.

    When I have repaired moldings such as these, I have found that the moldings are not made from a solid block as you have shown them on Sketch Up but cut from a board wide enough to accommodate the curves, and then set at an angle. Perhaps you might show that as well.

    • John Poole says:

      Hi Jane!

      Thanks very much for the good words! I hope this work ultimately is found useful by many interested parties. Although I’d cautioned in my (newly added) Postscript above that this exercise is intended primarily to express the historic carpentry peculiar to my own locale, I certainly hope that a broader audience of historians and restoration folks do indeed find it useful and interesting.

      Your point is well taken. There are numerous examples here of moldings being formed out of simpler sections, and when I eventually get to modeling them, I’ll be sure to include exploded perspectives, wherever possible.

      And, as a result of your comment, BTW, I’ve also just included a second perspective of the bed molding (see the final image above), which shows how the return was cut separately and joined to the main piece. Perhaps not exactly what you’re referring to, but the closest example I have thus far.

      Thanks again!

      ~ John

  6. Sebastian Eggert says:

    Dear John,
    Thanks for your articulate explanation of your drawing in SketchUp. From my perspective as a craftsman who has been called upon to make many restoration quality mouldings, please know that the original mouldings may have been based on a published classical pattern but the moulding planes that the carpenters used were hand made and often resharpened, thus through time the crossections of the shapes changed making each installation unique. I have drawers full of casing and crown knives that are close but not exactly the same shape, yet match their original models precisely.

    Ms. Radocchia comments that the moulding you describe may have been made of a thinner board set at an angle. This is correct, particularly with wider profiles such as crown mouldings (it allows for a less expensive piece of wood and easier fabrication), but smaller profiles are often made as a solid block of wood with a square corner referencing the horizontal and vertical planes and a moulded face just like John’s drawing. I try to follow the lead of the original carpenter and reproduce their work exactly. For the sake of a drawing the profile shape is probably enough, but for a true restoration quality recording of fact the entire shape should be reproduced as originally done, including the back angle if present. The White Pine series did that in the crossections, one of the many reasons this was such an important contribution to our understanding of early American architecture.
    Excellent discussion, and terrific work, all of you! Thank you.
    Sebastian Eggert
    Rain Shadow Woodworks, Inc.
    Washington State

    • John Poole says:

      Hi Sebastian,

      Thanks very much for this comment. Jane’s previous comment and yours have both contributed substantially to the material content of this post, for which I am extremely grateful!

      I am indeed aware that the hand made nature of molding planes, together with their patterns of wear and sharpening, made particular examples unique, and that was partly what motivated my comment in the Postscript above about the need to model the original pieces as found. Another motivation is that carpenters in my own region (and undoubtedly elsewhere, as well) often combined otherwise standard contours together in specific, unique ways, and, as such, the work of one individual can sometimes be discovered and traced throughout different homes in the same immediate locale (and sometimes even at some distance apart). I didn’t state all this in so many words in my Postscript, but I’ll probably go back now and work it in, along with a reference to your comment here, because I think it’s important that readers understand this.

      Regarding moldings constructed from thinner, angled boards, as previously pointed out by Jane, I completely agree with your position that any models intended to be used in guiding restoration would need to capture the manner of construction, as well. In my own case, I am of the mindset that as much historical detail as possible should be included in my models. So, generally, I’d include such detail if it were immediately obvious, or could at least be reliably inferred, but only to the extent I don’t have to damage anything of historical worth to get that information. There are many examples here that I have no intention of deconstructing in any manner, so external profiles will have to suffice. On the other hand, there’s much here also badly in need of repair, so such pieces might be good candidates for more detailed recording, since they need to be worked on, anyway.

      Thanks again for all the good words, Sebastian, and I hope you continue to read about my efforts here and provide feedback from your own experiences. Such feedback is invaluable to me, as it expands my own knowledge, but more importantly, helps me produce a much better end-product for my readers.

      Best always,

  7. Will Truax says:

    John -

    Good stuff.

    Isn’t it fun that it is on the verge of antithetical that we can bring the best of tooling in both the old and the new to what we do!

    Thanks for sharing.

    • John Poole says:

      Hi Will,

      Yes, it is! And I hope that this article has inspired you to begin recording and publishing historic timber bridges in SketchUp (that is, if you’re not doing so already; I see there are many interesting bridge models published in the 3D Warehouse and Google Earth).

      Thanks for visiting and commenting!

      - John

  8. Bill Smith says:

    John, I’m glad I finally had some time to look at this.

    1st, some great photos, particularly the bulls eye glass, a favorite of mine.

    You mention variations in the profile, one likely reason is that rather than a dedicated molder the carpenter was using hollows and rounds. I’ve seen some work done with these planes that is very consistent, if not quite perfect.

    Keep those sketchUp chops in shape!

  9. Great work John. As I’m sure you are only too aware of, we are in no danger of over documenting our architectural treasures. Whether it be photographs, measured drawings, observations or now sketch ups, the resulting documentation will prove invaluable as a research tool and for a permanent record at such time that we might lose that monument.
    I would like to make a couple of observations on your post. I think it very important to develop a chronology of modifications to the original fabric. Without seeing the parlor wall in person, I would note that the mantle shelf was a later addition. Also the bed moulding you are working on would appear to be a newer addition. A ogee w/ cove would be untypical of the period with an ogee/reverse ogee, coma/cyma reversa, being more probable. The cove of the bed moulding doesn’t match up with the vertical moulding. And last but not least, the rails and stiles of the raised paneling are not beaded but rather have a quarter round moulding. More affectionately known as a thumbnail moulding.
    Please accept my notes as constructive and intended to increase the accuracy of your very important endeavor. The Mansfield House is fortunate to have you as its steward. Keep up the good work.
    Wade I. Treadway

    • John Poole says:

      Hi Wade,

      Thanks very much for all the good words. I’m glad you found this article and have commented here…I’ve been a fan of your blog for some time now, and even listed it in the blog role of an earlier blog of mine (

      Part of my effort here is indeed to ultimately map a chronology to the inventory of things found. For now, I’m more concerned with establishing that inventory, but in the end, I want nothing less than a complete material history of the home. Also, either late spring or summer, I’ll be commissioning a dendrochronological survey of the frame, so as to at least establish a much more reliable baseline period of initial construction (I’ve found no evidence of a conversion from an older 2/2 home, for example, so it seems likely that the Mansfield house was constructed mostly from whole cloth, so to speak).

      I very much appreciate your comments on various combinations of mouldings and their probable periods. If you have any suggestions for good sources of information that specifically map moulding contours used here in colonial New England to probable periods, and their evolution over time, as well, I’d be extremely grateful. And if you don’t mind my throwing a particular question your way once in a while (without making a nuisance of myself!), that’d be very helpful, as well.

      One point regarding the thumbnail moulding: I’d used the terminology of one of my main historical sources, J. Frederick Kelly, who frequently referred to beveled panels with quarter round rails & stiles as “bead and bevel”, but am of the opinion that the term “bead” is perhaps better applied to something with sinkage on one or both sides (like a quirk, for example). So, I’ll perhaps just stick to thumbnail when referring to this.

      Oh, and one more thing: Philosophically, my documentation objectives are not to produce drawn or digital representations of these places so that there will be some record of them once they’re gone (although that certainly is a side effect that at least benefits history). But rather, to spread appreciation and awareness of just how rare these structures are, and what went into making them, and how these homes and their styles of construction will never appear again. Hopefully, that will motivate more folks to treasure them, just as they are, and want to keep them around, rather than deriding them as simply being old and of no use, or a priori in need to radical renovation or overhaul to be usable again, opinions that I hear so frequently they make me instantly cringe, every time…

      Thanks again, Wade! Hope to hear from you again sometime soon….

      ~ John

  10. John Leeke says:


    Another technique for transferring a moulding profile into SketchUp would be to photograph the profile gauge, import the photo into SketchUp and then develop the curves directly over the photo. This could result in greater accuracy in recreating the profile. If the photo remains in the SketchUp file then it contributes to the documentation.

    • John Poole says:

      Hey John,

      Yes, you’re absolutely right. Doing that would dispense of that intermediate step of transferring the shape and then “measuring” it, which is bound to produce errors, even if somewhat small ones.

      Perhaps photographing the profile directly would yield an even more accurate result, assuming, of course, that you were confident that the photographic plane of the camera and the corresponding, intended “spatial plane” or intersection of the moulding profile (if that concocted bit of terminology makes sense) were as close to being co-planar as possible. In my opinion, anything that eliminates intermediate steps is good.

      On the other hand, I personally tend to be a bit of a tinkerer, and enjoy the tactile nature of using a notebook and ruler, as much as I enjoy the 3D modeling. So, if there are three possible ways of doing something (anything), I’ll often try all three, multiple times, and compare results, and then finally settle on just one (or two). Just the way I am :-) .

      So, in future posts, I’ll show some examples of photographic import to SketchUp, and maybe try to compare its relative accuracy to the hand-drawn/transfer approach, on the same shapes.

      Thanks much for visiting and commenting!

      ~ John

  11. John Poole says:

    Hello, Princess Darling.

    OK. That’s what I’m here for — to do the heavy lifting (mathematical, or otherwise). And open jars. So just sit back, relax, and enjoy the Ozzy molding. ;-)


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