Existing Conditions Survey

Every dimension in a renovation is measured from something. When nobody wrote down which lines were measured, which came off a drawing from 1974, and which somebody assumed, the whole set inherits an accuracy nobody can state. The cost shows up at framing.

Workflow

Step 1. Fix the purpose, because it sets the effort

Ask, in one message:

1. What will these drawings be used for: a feasibility study, a permit set, a construction set, a shop drawing background?
2. What is the scope of work? A survey of the whole building for a kitchen renovation is waste; a survey of one room for a structural change is negligence.
3. What record drawings exist, from when, and were they as-built or as-issued?
4. What access is there: what rooms, what times, what is occupied, is there a ceiling to open, is there a basement and a roof hatch?
5. Who is going, with what, and how long do they have?
6. Is there a point cloud or a scan?

Record drawings are the trap. As-issued drawings show what was designed; what was built differs, and forty years of unpermitted work differs again. Establish which kind exists and treat both as unverified until measured.

Step 2. Build the capture list before going

The things people come back without, every time. Work the list and mark what this project actually needs:

• Overall dimensions taken as one continuous run, not as a chain of small ones.
• Floor-to-floor and floor-to-ceiling, in several places per floor. They differ.
• Structure: what is visible, where, what direction it spans, what is concealed.
• Every opening: width, height, head height, and which way doors swing.
• Wall thicknesses, and whether structural or not where that is visible.
• Levels: within a floor, and between floors and to grade. Old floors are not level and it matters at every threshold.
• Services: panels, meters, boilers, units, where risers run, where they enter.
• Above the ceiling: what is up there, in at least one place per area.
• Roof: assembly if visible, drains, penetrations, equipment.
• Below grade: what the basement shows about the structure and the water.
• Photographs, systematically, with a plan showing where each was taken from.
• What connects to a neighbour: party walls, shared structure, shared services.

Step 3. Measure so that errors are found on site

The method that separates a survey from a set of numbers:

• Close every loop. Measure a room's walls and check the sum against the overall dimension taken separately. A closure that does not close is found in ten seconds on site and in three weeks in the office.
• Take running dimensions, not a chain of individual ones, so errors do not accumulate.
• Take one long overall dimension per elevation and per floor to hold everything else against.
• Measure diagonals in rooms that matter. Nothing is square.
• Record the datum you used and use the same one everywhere.
• Note what you could not reach and why, at the time, on the sketch.

Step 4. Record every line with its provenance

The whole point. Every element in the resulting drawing is one of:

Mark	Means
Measured	Somebody measured it, on a date
Record	Taken from a record drawing, with its date
Assumed	Inferred, patterned from elsewhere, or guessed

Report the counts, and put them on the drawing. Anything not marked is assumed, and a set that does not distinguish these is a set where every dimension carries the accuracy of its worst line.

Concealed structure and concealed services are almost always assumed. Say so rather than drawing them confidently.

Step 5. Produce the two lists that come after

To be verified before design proceeds. Things a scheme would be built on that are currently record or assumed, ordered by what depends on them.

To be opened up, and by whom. Where a wall, a ceiling or a floor has to be opened, what would be learned, when it has to happen to be useful, and who carries the cost and the making good. A programme with no decision point after opening up is a programme that will be broken by what is found.

Then the specialist hand-offs, each named:

• Structural investigation and capacity: the structural engineer.
• Hazardous materials: a survey by a qualified party, before the scope is fixed. Point at adaptive-reuse-architect.
• Land survey and levels to a datum: a surveyor.
• Services capacity and condition: the MEP engineer.
• Building condition and defects: a condition surveyor.

Step 6. Report

• The provenance counts, first.
• What was captured and what was not, with why.
• Closures that did not close, and what was done about them.
• The verify list and the open-up list.
• The specialist hand-offs, with which have been commissioned.
• What the drawings are and are not fit for, stated plainly, so nobody uses a feasibility survey as a construction background.

Step 7. Save

Ask where. The record is a file that gets read for the life of the project, and the provenance marks have to survive into the drawing set.

Rules

• Fix the purpose before planning the visit. It sets everything.
• Every line is marked measured, record, or assumed. There is no fourth state and nothing is unmarked.
• Treat record drawings as unverified, including as-builts.
• Close every loop on site.
• State what the drawings are fit for, on the drawings.
• Never record a condition judgement. That is a specialist's.
• Name the hazardous materials survey before the scope is fixed, every run.

Anti-patterns

• Redrawing the record drawings and calling it a survey.
• Chaining small dimensions across a long wall.
• Drawing concealed structure with the same line weight as measured structure.
• Coming back without floor-to-floor heights, which is the most common omission.
• Assuming a building is square, level, or symmetrical.
• Surveying the whole building for a small scope, or one room for a large one.
• Fixing the programme before the hazardous materials survey.
• Producing a drawing that does not say what it is fit for.

Resources

None. This skill is one file. Output is written directly at the path you choose.