Drafting Service Files: How to Produce Shop Drawings for Historical Buildings

How to Produce Shop Drawings for Historical Buildings

The process of creating a set of shop drawings involves a great number of people.

From the material supplier, to the customer, to the fabricator, to the engineer, and the architect, each pair of eyes that scrutinize the drawings have a different take. And often each person adds their own notations and revisions to the drawings.

Needless to say, the process of producing accurate shop drawings is complicated.

But when you’re dealing with a historic district or a landmark preservation area, it gets ever more complicated.

Normally, when validating shop drawings, you have a series of questions you have to ask yourself:

  • Do they match the intent in the architectural plans?
  • Can the frames be constructed and installed?
  • Are all parts and pieces called out for assembly?
  • Will all systems function under the design load?

These questions are pretty straightforward and easy to answer.

However, when you’re working with an historic building, you have to consider all of the questions above while also matching the original style of the building. Depending on the building’s age, this task will range from extremely difficult to virtually impossible.

One of the biggest problems you’ll face is this: You might have no idea what was originally installed because complete construction documents for historic buildings are hard to come by.

What’s more, there’s a good chance the building has been remodeled before, so you have to decipher what’s original and what’s an upgrade.

What often happens with these projects is you’ll submit your drawings to a Landmark Preservation Committee (LPC), and they’ll compare them to a 3×5 black-and-white photo of the building that was taken from across the street 80 years ago. This makes it very easy for reviewers to find issues with your drawings.

For instance, one of the comments I’ve received from such a review is “I feel like the original windows had thinner mullions”. And I get feedback like this all the time. They might very well be correct, but without accurate detailed drawings, there’s no way to know for sure.

There’s also a chance the original drawings are in fact available.

This might sound like a great thing for the project, clearing up most design uncertainties, but it can also open the door to other problems. One of the biggest problems stems from the fact that building materials have changed (a lot) over the decades.

Single pane wooden windows have been replaced with highly engineered systems that architects could only dream of 100 years ago. So should you install an inferior, historically accurate product, or an advanced system with a similar aesthetic?

Luckily, there are material suppliers in the market with product lines designed to mimic historic designs, but with modern performance. Wood veneered engineered materials or wood multi-pane systems are two examples commonly used to replace traditional constructions.

The most important thing I’ve learned from experience:

Patience is key.

No matter how challenging the task, you need to get approval from LPCs before starting construction. They want to ensure the new construction is done in the spirit of the old design. But building owners, understandably, want to improve the performance of their property. Both goals are in the best interest of the community.

Clear communications (especially with the LPC) from the beginning to the end of the project will help avoid any snags along the way, keeping everyone happy.

Jon Gura
Engineering Manager

Primary keyword: shop drawings for historical buildings
Secondary keywords: historical building designs