Drawing Interpretation

• Schedule: convey additional info that would take too much drawing space. Includes number or oetter designation of each item with a description.

• Specification: serve as standards for selecting materials. If discrepancy between spec and drawing, spec takes precedence.

  • housing may spec on drawings, commercial may have a separate document.

  • CSI (construction specification institute) made a standardized spec system.

• Housing blueprint order: site plan→ floor plan → elevation plan → sections and detail drawings

• Legal description: alberta was surveyed using a system called “Third System or Township Surveys”

• Meridian:

  • lines from north to south are meridians or lines of longitude. In alberta these are called range lines.

  • East to west is parallels or latitude

  • lines. In alberta these are called township lines. Usually 6 miles on each side.

  • LSD 13-10-1-1-W4

    • 10 acre parcel in NW of legal subdivision 13, section 10, township 1, range 1, west of fourth meridian

• Elevations: height above a given reference point.

  • Geodetic Elevation : based on mean sea level. Reference points are called datum points.

    • Modified Geodetic removes a common nunber from the drawing- used in construction. If elevation is 1374, sometimes itll be 374 since the 1000 doesn’t matter as it’s common to all.

  • Architectural: Assigned, usually main floor. Still uses Geodetic but made easier to work. If the real elevation is 1894, the architect might call that as 100 as it’s easier to work with.

• Contour lines: used to indicate areas of same elevation . As they get closer, it means the slope is steeper.

• Elevation views show all 4 sides of a building to show the elevation.

• Site plan drawings show elevation views.

• Scale:

  • each side on a triangular scale ruler can have 4 different scales (2 per edge). Read from left to right or right to left depending on which scale you use in the same edge.

  • Imperial: based on fraction of an inch per foot. If a scale is said at 1/4”, it means every 1/4” on the drawing means a foot. This would mean the object is reduced 1/48 of its original size.

  • Metric: metric would be 1:100 (numerical ratio)- every mm, there is D in real world.

  • Resi commonly 1:50 (1/4” per foot) commercial commonly 1:100 (1/8” per foot)

  • Cannot mix metric and imperial scales, they do not match exactly

• using a tape measure: to obtain req’d measurement, measure your line with a tape and divide by scale (for example 1/4in/ft).

  • if you use metric, measure in mm and multiply it by the scale. 43mm in a 1:50, would be 2150 mm on the job.

obj 3 dimensioning imperial and metric

• Buildings are usually dimensioned from outside wall to the :

  • edge

  • or center

  • or openings or interior of walls

• Interior dimensions are usually from centre of partition or to the face of the wall

• Orthographic dimensions to be kept as simple as possible

  • common views share common dimensions, do not show duplicate as it leads to confusion.

  • Centre to centre or centre to face

Obj 4 symbols

Add flashcards of symbols

• Symbols on drawings should be identified in a legend.

Obj 5&6 - 5 divisions of a drawing package, purpose

1. Architectural - Designated by letter A followed by #

   • building site plan- address/legal description, overhead view of building site, building orientation, utility orientation, drawing scale, geodetic elevations

   • foundation plan - footings, piles, grade beams, underground piping/utility

   • floor plan- interior plan view of building. Locate walls, doors, windows, plumbing fixtures, furnaces, hot water tanks.

   • exterior elevation - indicated by orientation- exterior walls and elevations, vent terminals, rainwater leaders, roof penetrations

   • Interior elevation- inside walls, sections of interior like bathrooms and kitchens

   • Details- close up view of construction, enlarged aread circled and tagged via identification bubble.

   • window/door finishing schedules - size and desc for windows, doors, wall finish. Usually table form with a number and letter.

2. Structural- letter S followed by number

   • May be incorporated into architectural drawing

   • structural, load bearing, trusses, footings, columns

3. Mechanical- M, or P (plumbing), H (HVAC), FP (fire protection) followed by nunber

   • plumbing, hot water, hvac, fire protection

   • Piping, ductwork, drainage, venting, utilities

   • Sometimes routing is up to plumber,

4. Electrical - not touched on, doesnt mention letter

5. Landscaping - doesnt mention letter

   • grade (ground elevation) , sidewalks, patios, gas lines under driveways, rainwater leader terminations

• notes are required to be read to fully understand requirements.