Drawing Units: Decimal vs. Architectural

[Michael Lynskey]

I come from a surveying/civil engineering background where we worked almost exclusively in decimal feet units, except for occasional detail callouts.  Landscape Architects do much more custom detailing, which appears to be mostly in architectural units (inches).  What is the cutoff point between using decimal units and architectural?  Is it simply a question of scale, where larger plans, intended to be interpreted by surveyors, would use decimal whereas details at the “craftsman” level are more likely to be measured using inches?  Do residential or small design/build projects still use decimal or are they in inches?  Does it just depend on who you are collaborating with, be it architects vs. civil engineers? 

It would seem that any information that references a larger system of organization, such as coordinate systems or any type of elevation reference would need to be in decimal units, whereas more self-contained design areas might be okay in inches.  What are the current protocols out there, or how do you current professionals handle the fundamental differences in drawing units? 

Thanks.

[Trace One]

I work for a state department of transportation that spent 5 to ten years transforming everything they had to metric, in the nineties, because we had a mandate from our federal government to change with the times! We then discovered that no-one else had changed to metric, and we had a really hard time with contractors bidding in metric, they just didn’t get it, or something, and so we now have gone back to what they call ‘english’ …hee!
I like english – I think the divisions are more natural.. But man the engineers all want metric..English seems basically indefensible, in the overall scheme..

[nca]

I generally work in decimal for plan layout as most of the work is being done in conjunction with engineers/surveyors. Vertical construction I generally use architectural.

[Anonymous]

I think and work in decimal foot units then convert to architectural units on layout plans and details for presentations or final drawings. It’s easier for me work in decimal units, but I convert to architectural units to be consistent with the architectural drawings.

I use to work with a designer at a landscape design/build firm who came from a construction background and he would do these small grading plans with spot elevations in architectural units. The drawings used to look so foreign to me.

[Thomas J. Johnson]

Spot elevations / grading are the only thing I would do in decimal form. Everything else I’d do in architectural. I think it all depends on who is using the drawing. Surveyors are going to want to use decimals. Contractors / laborers (using tape measures) generally want to use architectural.

This discrepancy is yet another reason we should toss the whole English system (sorry Britain) and convert to metric. Metric is simple, intuitive and just plain makes sense…

[Dennis J. Jarrard, PLA, CLARB]

I think it depends mostly on who you are collaborating with. Most of my base information comes from surveyors or civil engineers and it is always in a decimal format. There is nothing worse than getting a site plan from an architect that is drawn to architectural units. You can use architectural units when working on your design details, especially those which you need to enlarge enough to show the greatest amount of detail.

[Michael Lynskey]

I’m a little surprised on how little consensus there is on something this fundamental to our practice, although this is an admittedly small sampling of opinions. I guess it’s just another aspect of our profession, being sort of an intermediary between the other more specialized fields, that we need to be fluent in either system of measurement/labeling and know when to use each accordingly.

I’m a civil technician turned MLA student and can definitely say that engineers & surveyors would scoff at a grading plan done in architectural units. Layout is more tricky and I agree with Nick that structural elements might need to be architectual, while larger-scale site work would more natually be in decimal feet. Highly structural urban plazas, etc., would be in architectual, I would think. I guess there’s no clear answer…interesting.

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