Best Practices for blueprinting legacy homes


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I am just completing a plan on an as-built 70's two story house for a kitchen remodel and two first floor additions with roof modifications. There was an existing print but there were at least two undocumented additions/modifications from the original blueprint. Typical for the era and area. 

 

I am looking for best practices on handling a scenario like this. What I learned from this from a CA perspective is:

  1. Forget any existing blueprints unless the customer agrees to it being the bible. Nice for a visual reference, but so many things could be off. Leading with the existing blueprint is trouble.
  2. Normal CAD work normally defines the external reference points (i.e. Datums) as the constraints, and you work from the outside to the inside. This led to trouble for me in several areas, especially using the blueprint as the initial reference point.  I now believe the best practise to be the opposite and the interior wall layout is the holy grail.
  3. Using walls type baselines can create surprises unless you check every wall. The definition can affect your core measurements. There can be cases where some walls are shimmed, built-up, or what to make things match up on modifications. Best to measure all interior walls dimensions as best you can to set the baseline wall type options.
  4. Standard measure practice, find the longest dimensions to eliminate accumulative error using a reference wall. These become the critical measurements.
  5. Set any dimension defaults for internal measurements to the surface.
  6. Set any dimension defaults for structural/truss work to the main layer.
  7. Mixing an interior kitchen mod with structural changes in other areas on one plan requires different dimensioning defaults (i.e. 5 and 6)

 

I could see how creating a new plan view could assist in this mixture, etc. Also, set the snap settings very tight? Any experiences that might tighten this up?

 

 

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16 minutes ago, PMMully said:

I am just completing a plan on an as-built 70's two story house for a kitchen remodel and two first floor additions with roof modifications. There was an existing print but there were at least two undocumented additions/modifications from the original blueprint. Typical for the era and area. 

 

I am looking for best practices on handling a scenario like this. What I learned from this from a CA perspective is:

  1. Forget any existing blueprints unless the customer agrees to it being the bible. Nice for a visual reference, but so many things could be off. Leading with the existing blueprint is trouble.
  2. Normal CAD work normally defines the external reference points (i.e. Datums) as the constraints, and you work from the outside to the inside. This led to trouble for me in several areas, especially using the blueprint as the initial reference point.  I now believe the best practise to be the opposite and the interior wall layout is the holy grail.
  3. Using walls type baselines can create surprises unless you check every wall. The definition can affect your core measurements. There can be cases where some walls are shimmed, built-up, or what to make things match up on modifications. Best to measure all interior walls dimensions as best you can to set the baseline wall type options.
  4. Standard measure practice, find the longest dimensions to eliminate accumulative error using a reference wall. These become the critical measurements.
  5. Set any dimension defaults for internal measurements to the surface.
  6. Set any dimension defaults for structural/truss work to the main layer.
  7. Mixing an interior kitchen mod with structural changes in other areas on one plan requires different dimensioning defaults (i.e. 5 and 6)

 

I could see how creating a new plan view could assist in this mixture, etc. Also, set the snap settings very tight? Any experiences that might tighten this up?

 

 

That's a really good summary in my opinion and very close to practices I've adopted over many years of measuring 'legacy' as built properties. As to #1 I will use existing blue prints as a starting place for the initial measure but never rely on them as I have never measured a house that was actually built to that legacy blue print. Difficult for some clients to understand as they sometimes feel half the work is already complete but I make sure they understand before beginning.

 

I don't measure exteriors any more and find #4 to be one of the most important tips to getting at least close to the existing floor plan. With #5 a close second. Internal walls with drywall on a standard 2 x 4? Or older construction with plaster on a true 2 x 4?

 

The one thing that I've never resolved in any legacy measure is the 1/8's, 1/4's, and 1/2's that get eaten when measuring. Round up? Round down? Measure to the 1/8 of an inch? As those roundings accumulate there always seems to be an inch that goes missing. It's an art as to where that missing or additional inch should go and placing it in the wrong location can be a lot of no fun.

 

I think that last comment regarding any measure as an art instead of a dead on science might the most appropriate and knowing a bit about construction and what comes next allows for that art to create a set of plan that won't sabotage the builder.

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I measure interior walls. And same as you, I try to shoot long distances with the laser to get overall dimensions so I can check that against my wall thickness determined measurements of a series of rooms. There will be a few areas on the outside that need a measurement to help with the start of the drawing. Then, this varies based on the who I am on a job. If I am a the general contractor, I can draw without a high level of CYA since I will be on the job site. If I am a building designer and someone else is going to build. Almost every string of dimensions has a "V.I.F." in the string.

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I have now built a plan view that I call "Internal Working Set" that has the default set & dimensions set correctly. So far it seems I can switch between the two allowing for the measurements the interior dimensions to alternate based on the work I am doing on a single plan. I have learned to not use the kitchen/bath plan view unless it is strictly that in a plan, which I do about 30% of my time.

 

@Gawdzirayou got that right, as I am moving in a direction to support multiple builders and moving away from field work eventually, I need to set up for "lowest common denominator" of field worker. In all new construction its simple, in the mixed mode not so much. I can see the need for a Note to call that out. In my layout border I have the VIF so its on every page.

 

I have one PE that says I put too much detail in, "our plans are for GCs, not Ikea buyers". I have another that likes the detail core correct. I pick between the four of them now depending on the job complexity and customer. It is mostly the old school hand draw guys that are the the former. Most cad guys like the detail. But in all cases, too much detail can be detrimental.

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16 minutes ago, PMMully said:

But in all cases, too much detail can be detrimental.

Matches my experience as well and any good builder will not want details to get in his way to 'build it right' or exceed any detail that may be an actual bare minimum and only code compliant. I have not added any V.I.F notes to dims on an 'as built' but will start today. Will probably add a general note instead of adding to the dim string but will add something.

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The danger with the general note "V.I.F." is that the general notes are where the donut is placed when reading the drawings. Put the critical info where it is going to be read. 

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3 minutes ago, Gawdzira said:

The danger with the general note "V.I.F." is that the general notes are where the donut is placed when reading the drawings. Put the critical info where it is going to be read. 

Understood and agree but for me the string location may clutter things up a bit. I'll try both and try not to hide a general note under the donut.

 

Maybe like this?

 

 

DONUT 1.png

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always measure walls in at least two places

 

my house was renovated by prior homeowners 

bedroom wall off the living room was 2" off from one end to the other

 

Lew

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The one thing that I've never resolved in any legacy measure is the 1/8's, 1/4's, and 1/2's that get eaten when measuring.

 

Using a Disto I measure and model to 1/16 and enter all numbers as 16th's 

so 3/4 is entered as 12/16 - makes doing math so much easier

 

unless its in a critical area I accept a few 2" discrepancy's - but note measured dim as a reference

 

at the end I set all dims to 1/2" rounding or to 1" rounding

 

Lew

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15 minutes ago, HumbleChief said:

Understood and agree but for me the string location may clutter things up a bit. I'll try both and try not to hide a general note under the donut.

 

Maybe like this?

 

 

DONUT 1.png

Know your audience.

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3 hours ago, PMMully said:

Standard measure practice, find the longest dimensions to eliminate accumulative error using a reference wall. These become the critical measurements.

 

This is key. I will verify internal measurements to the survey plan, to ensure they are "reasonably close" typically less than 2". I try as much as possible to have verification dimensions from an outside wall, after measuring internal rooms, as a double check.

 

I dim to the stud on plans and leave the room label to the surface, unless requested otherwise. It ensures a couple things get built correctly, framing for a tub,shower, calculations for beams. This requires a little cheating in CA because CA will bump objects to the drywall/finished surface. A purchased 5' shower base is typically 59-1/2 or 59-3/4". So you need to adjust the shower base in CA to be 59 instead of 60 to fit within the drywall. I noticed this when the framing dimension was coming out at 61" instead of 60".

 

As well, I dimension typically at hip level. More often than not, houses are not plumb. I notice kitchen cabinet guys measure at multiple heights to avoid this problem presumably. My own 1970's house has one outside wall off 1" over the 8'

 

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3 hours ago, HumbleChief said:

 

DONUT 1.png

 

 

Thanks for the laugh Larry :) 

 

And to Allan for a reminder to add V.I.F to As-Built Drawings....

 

Mick.

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