Which drawings to issue at SD, DD and CD

Sheet by sheet: what you issue at each phase, at what scale, what each drawing shows and how many there are. With two measured projects — a ten-storey building with a hundred apartments, and a two-storey house — so the numbers stop being «it depends».

The drawing set is the product

A practice does not deliver a design. It delivers a package of sheets with an agreed scope. And almost every argument about fees, programme and scope starts in the same place: nobody wrote down how many sheets, at what scale, showing what.

This guide answers that. If what you need is which phase a project is in and what can honestly be promised at each one, that is the phases guide. This is the other half: what comes out of the plotter.

The phase says how much you know. The drawing set says how much you deliver. They are contracted separately and argued about together.

How a sheet is numbered

The US convention — the one that travels furthest in international contracts — encodes the sheet in two parts: the discipline and the type of view. Once you see it you cannot unsee it: A-301 is architectural, sections, the first one.

CodeFirst letter · disciplineFirst digit · type of view
GGeneral — cover sheets, index, notes0 · General: symbols, legends, abbreviations
CCivil — earthworks, site utilities1 · Plans
LLandscape2 · Elevations
SStructural3 · Sections
AArchitectural4 · Enlarged views
IInteriors5 · Details
PPlumbing6 · Schedules and diagrams
MMechanical — HVAC7 and 8 · User defined
EElectrical9 · 3D views
FFire protection

So A-101 is the first architectural plan, A-201 the first elevation sheet, A-401 the first enlarged plan and A-601 the first schedule. The number tells you what you are about to see before you open it, which is worth a great deal when the set runs to a hundred and eighty sheets.

Across much of Latin America the convention is different: ARQ-01, EST-01, HID-01, ELE-01 — sequential within each discipline. It works, but it loses the view type: ARQ-27 does not tell you whether you are opening a plan or a detail. If you work with teams there, know both — and declare which one you use on the general notes sheet.

Where the scale comes from

Scale is not chosen by habit. It is chosen by one simple calculation: what fits on the sheet. And what fits decides how many sheets you need, which is where the drafting budget comes from.

At 1/8"=1'-0", one inch of paper is eight feet of building. An ARCH D sheet is 24 × 36 in, and after the title block and margins you are left with roughly 33 × 22 in of drawing area. The arithmetic does itself:

SheetUsable areaCovers at 1/4"=1'Covers at 1/8"=1'Covers at 1/16"=1'
ARCH C · 18×24"21 × 16 in84 × 64 ft168 × 128 ft336 × 256 ft
ARCH D · 24×36"33 × 22 in132 × 88 ft264 × 176 ft528 × 352 ft
ARCH E · 30×42"39 × 27 in156 × 108 ft312 × 216 ft624 × 432 ft
A1 · 594×841 mm780 × 550 mm39 × 27 m (1:50)78 × 55 m (1:100)156 × 110 m (1:200)

Usable area depends on each office's title block. These figures assume a side title block of about 6 in and 1 in margins. The last row is the ISO equivalent, with its metric scales in brackets.

With that table the decision stops being an opinion. Our example building has a footprint of 131 × 72 ft (40 × 22 m): at 1/8" it takes 16 × 9 in on an ARCH D sheet that gives you 33 × 22 — plenty of room left for dimensions and notes. At 1/4" it would take 33 × 18 in and only just squeezes in, with nothing left over.

Now look one row up: on an ARCH C sheet the same plan at 1/4" does not fit at all. Scale and sheet size are one decision, not two. Before arguing about the scale of a plan you have to know what paper it prints on — and whoever receives the set has to be able to unfold it on a site table.

The house measures 39 × 33 ft (12 × 10 m): at 1/4" it takes 10 × 8 in and fits on almost anything. At 1/8" it would be 5 × 4 in — far too small to dimension without the figures colliding. That is why houses are drawn at 1/4" and towers at 1/8".

If your plan does not fit at the scale you need, do not drop the scale. Split it with a match line. An illegible drawing is not cheaper — it is more expensive.

Scales by drawing type

Drawing typeLarge buildingHouse / small workMetric equivalent
Site plan1"=40' – 1"=20'1"=20' – 1"=10'1:500 – 1:100
Floor plans1/8"=1'1/4"=1'1:100 · 1:50
Enlarged plans (unit, core)1/4"=1'1/2"=1'1:50 · 1:25
Enlarged baths and kitchens1/2"=1'1/2"=1'1:25 – 1:20
Elevations1/8"=1'1/4"=1'1:100 · 1:50
Building sections1/8"=1'1/4"=1'1:100 · 1:50
Wall sections3/4"=1'3/4"=1'1:25 – 1:20
Reflected ceiling plans1/8"=1'1/4"=1'1:100 · 1:50
Construction details1½" · 3"=1' · full1½" · 3"=1' · full1:10 – 1:5 – 1:2

The two projects we are comparing

Everything that follows is counted on these two. If yours resembles one of them, interpolate.

Project A

Apartment building

Storeys
10 above grade + 1 basement
Units
100 apartments
Unit types
5, repeated
Footprint
131 × 72 ft · 40 × 22 m
Gross area
≈ 108,000 sq ft · 10,000 m²
Project B

Single-family house

Storeys
2 + roof
Units
1
Unit types
nothing repeats
Footprint
39 × 33 ft · 12 × 10 m
Gross area
≈ 2,150 sq ft · 200 m²

The building has fifty times the area of the house. Hold on to that number: in a moment you will see how many times more sheets it needs, and it is not fifty.

SD · Schematic Design — the scheme, and nothing more

The question an SD set answers is «is this the right building?». It carries no construction dimensions, no details and no complete schedules. If your SD already has rebar layouts, you are spending on something that can still change entirely.

SheetWhat it showsScaleBuildingHouse
Cover and indexName, phase, date, sheet list—11
Site planLot, access, orientation, setbacks, immediate context1"=40' / 1"=20'1— (with roof plan)
Basement planParking, ramp, plant rooms, cores1/16"=1'1—
Ground floor planEntrance, lobby, retail, relationship to the street1/16"=1'11
Typical floor planOne only, because it repeats. Layout and core1/8"=1'11 (second floor)
Unit typesThe 5 apartment plans, with areas and indicative furniture1/4"=1'1–2—
Roof planFalls, equipment, common terraces1/16" / 1/8"=1'11
ElevationsAll four. Heights, solid and void, general materials1/16" / 1/4"=1'1–21
SectionsTwo: one long, one through the core. Clear heights1/16" / 1/4"=1'11
Area scheduleArea by use, by floor and by unit type. Planning ratios—1— (fits on cover)
Massing / 3DTwo or three views that explain the siting—1–21

SD total — building: 10 to 14 sheets · house: 5 to 7 sheets.

Look at the typical floor plan row: one sheet for ten storeys. That principle — draw what repeats once, and say where it repeats — is why a hundred-apartment building does not cost a hundred times a house. Whoever ignores it draws ten identical plans and gets paid the same as the person who drew one.

DD · Design Development — dimensioned and coordinated

Here the set grows sharply, for two reasons at once: the other disciplines arrive, and architecture moves from showing the scheme to fixing dimensions. The question it answers is «does it all fit, and how big is it?».

What architecture adds

SheetWhat it showsScaleBuildingHouse
General notesSymbols, abbreviations, general notes, naming convention—21
Site planLevels, paving, site utilities, access resolved1"=20'11
Dimensioned plansBasement, ground, second if different, typical, roof. Now with dimensions and grids1/8" / 1/4"=1'5–63
Enlarged unit plansEach unit type, dimensioned, with fixed joinery1/4"=1'3–4—
Enlarged coresStairs and lifts: treads, risers, pits1/4"=1'21
Baths and kitchensEnlarged, with fixtures, tile heights and plumbing points1/2"=1'21
ElevationsWith level dimensions, window types tagged, materials called out1/8" / 1/4"=1'2–31–2
Building sectionsTwo or three. Clear heights, floor build-ups, ceilings1/8" / 1/4"=1'21–2
Wall sectionsThe vertical cut through the envelope, layer by layer3/4"=1'2–31
Reflected ceiling plansCeilings, fittings, diffusers, access panels — coordinated with MEP1/8" / 1/4"=1'1–21
SchedulesDoors, windows and finishes. They start here and close at CD—3–41–2

Architecture at DD — building: 28 to 35 sheets · house: 10 to 13.

And the other disciplines arrive

This is the jump that surprises anyone used to drawing architecture alone. At DD you are no longer issuing a set: you are issuing four or five sets that have to agree with each other.

DD total — building: 70 to 90 sheets · house: 20 to 26.

CD · Construction Documents — build from it without asking

The question is no longer whether it fits. It is «how exactly is this built?». What grows here is details and schedules, not plans — the plans were already there at DD, and what happens to them is refinement.

What gets addedWhat it showsScaleBuildingHouse
Envelope detailsJunctions, terminations, joints, waterproofing, anchors1½" – 3"=1'8–143–5
Interior detailsSkirtings, heads, fixed joinery, tiling, ceilings1½" – 3"=1'6–102–4
Core detailsFull stair, balustrades, handrails, lift doors3/4" – 3"=1'3–51–2
Wall typesEach type in plan and section, with layers and thicknesses1½" – 3"=1'2–31
Closed schedulesDoors, windows, room finishes, hardware, fixtures—6–92–4
Setting-out plansGrids, coordinates and dimensions for laying out on site1/8"=1'2–31
SpecificationsThe written document. Sits outside the set, and governs as much as it does—documentdocument

Architecture at CD — building: 55 to 75 sheets · house: 18 to 25. Across all disciplines: building 140 to 200 · house 35 to 50.

Specifications are not an appendix. In a well-drafted contract, where the drawing and the specification contradict each other, the specification governs. A CD set with no written specifications is not a CD set: it is a well-drawn DD set.

The summary, and the number that matters

PhaseBuilding · 10 storeys, 100 unitsHouse · 2 storeysRatio
SD · Schematic Design10 – 145 – 7≈ 2×
DD · Design Development70 – 9020 – 26≈ 3.5×
CD · Construction Documents140 – 20035 – 50≈ 4×

Ranges, not exact figures: they vary with country, contract, how demanding the client is and each office's habits. They are for sizing the work and arguing a scope — not for signing without reading.

The building has 50 times the area of the house and needs 4 times the sheets. A drawing set does not grow with square footage. It grows with variety.

That sentence should change how you price. What multiplies the work is not size: it is how many different things there are. A hundred-apartment building with five unit types is less drawing than twenty houses that are all different, even at three times the area.

And the inverse: if your project is large and repetitive, anyone charging you by the square foot is overcharging. If it is small and every part is different, whoever charges by the square foot will lose money — and will get it back by cutting the set.

The most common mistakes

Frequently asked questions

How many drawings are in a set of architectural plans?

It depends on the phase and on variety, not on area. For a ten-storey building with a hundred apartments and five unit types: roughly 10–14 sheets at SD, 70–90 at DD and 140–200 at CD across all disciplines. For a two-storey house: 5–7, 20–26 and 35–50 respectively.

What scale are floor plans drawn at?

1/8"=1'-0" for buildings and 1/4"=1'-0" for houses and small work — and not by tradition: it is what fits legibly on the sheet. Enlarged plans — a unit, a core, a bathroom — go at 1/4" or 1/2", and construction details between 1½"=1'-0" and full size.

What does A-101 mean on a drawing?

In the US convention the letter is the discipline and the first digit is the type of view: A for architectural, 1 for plans. So A-101 is the first architectural plan, A-201 the first elevation sheet, A-301 sections, A-501 details and A-601 schedules.

How many typical floor plans do you draw for a ten-storey building?

One, if the ten floors are the same. You draw the typical plan and note which levels it repeats on. Drawing ten identical plans multiplies the drafting work and, far worse, multiplies every revision by ten.

What is the difference between a building section and a wall section?

A building section is drawn at the same scale as the plan and exists to explain heights, floor build-ups and how spaces relate. A wall section goes at 3/4"=1'-0" and exists to build the envelope: it shows the layers, the anchors, the terminations and the junctions with slab and glazing.

Are specifications part of the drawings?

No: they are a separate document, and in most contracts they govern over the drawing where the two disagree. A CD set with no written specifications is incomplete, however finished the sheets look.

What the next guide covers

This guide says which sheets you issue. The next one says how you draw inside them: how to dimension a plan and which dimension strings it needs, how to tag doors, windows and rooms, how wall types are named, and how door, window and finish schedules are set up so they come out of the model instead of being typed by hand.

The drawing set, and what comes out of it

VDClens carries a project from the model to the site in one application: the sheets and their revisions, the quantities that come off them, the budget and the field. Every number stays tied to the sheet and the revision it came from.