THE SCOPE GAPS THAT ACTUALLY COST MONEY.

Scope gaps are not exotic. The same nine or ten items account for most of the money that leaks out of a buyout, and they leak for a structural reason: each one sits on a seam between two trades, where both parties can read the tender documents honestly and still both assume the other is carrying it.

What follows is the working list — the recurring gaps, roughly ordered by how often they show up on GTA mid-rise work, with the typical exposure range and the specific wording that closes each one. There is nothing proprietary here. If you use it as a checklist against your next buyout and never speak to us, the article has done its job.

The short version

1. Hoisting and crane access

Why it leaks: Every trade assumes free crane time and unlimited hoist access. The schedule cannot deliver it to all of them.

The wording that prevents it: State crane availability hours, hoist capacity and the number of picks each trade may assume — in every scope, not just the steel one.

Typical exposure $25k – $180k · 05 Masonry · 06 Steel · 09 Glazing · 16 HVAC

2. Winter conditions and temporary heat

Why it leaks: GTA winters run December through March. CSA standards require heat and protection that trades price out and then claim back.

The wording that prevents it: Name the date the building will be enclosed and heated, and split ambient heat (GC) from local protection (trade) explicitly.

Typical exposure $30k – $250k · 04 Concrete · 05 Masonry · 11 Drywall · 13 Painting

3. Cutting, coring and patching

Why it leaks: “By others” in every letter means the GC carries it unpriced, across the whole building.

The wording that prevents it: Make each trade responsible for its own cutting, coring, GPR scanning and making good — as a written inclusion.

Typical exposure $15k – $90k · 04 Concrete · 11 Drywall · 16 HVAC · 17 Plumbing · 19 Electrical

4. Firestopping ownership

Why it leaks: Building will fail occupancy on firestopping. Every trade excludes it; the firestop sub prices a count that is always low.

The wording that prevents it: One firestopping package, unit-rate based, with a stated estimated count and a re-measure clause.

Typical exposure $20k – $120k · 14 Fire · 16 HVAC · 17 Plumbing · 18 Sprinkler · 19 Electrical

5. Air barrier continuity

Why it leaks: The transitions at window perimeters and slab edges belong to no single trade, and that is exactly where the assembly fails.

The wording that prevents it: Draw the air barrier as a continuous line and name the trade that owns each segment and each transition.

Typical exposure $40k – $400k · 07 Carpentry · 08 Roofing · 09 Glazing

6. Excess soil under O. Reg. 406/19

Why it leaks: Tracking, testing and a licensed receiving site are now statutory. Bids written before 2021 habits changed still assume free disposal.

The wording that prevents it: Require the soil management plan, the destination site and the per-m³ basis in the excavation scope.

Typical exposure $50k – $400k · 03 Excavation · 20 Site

7. Access panels

Why it leaks: Specified by MEP, installed by drywall, bought by nobody.

The wording that prevents it: Name the supplier and the installer separately, and set an allowance count.

Typical exposure $8k – $45k · 11 Drywall · 16 HVAC · 17 Plumbing · 18 Sprinkler

8. Blocking and backing

Why it leaks: Wall-mounted items need backing that nobody prices until millwork arrives on site.

The wording that prevents it: Issue a backing schedule with the tender and put it in the carpentry scope.

Typical exposure $10k – $60k · 07 Carpentry · 11 Drywall

9. Starters, disconnects and control wiring

Why it leaks: The classic mechanical/electrical seam — supplied by one, installed by the other, assumed by both.

The wording that prevents it: Use a supply/install matrix for every powered piece of mechanical equipment.

Typical exposure $25k – $140k · 16 HVAC · 19 Electrical

The pattern underneath all of them

Read the list again and one thing stands out: almost none of these are disagreements about what the work is. Everyone knows the firestopping has to happen. The dispute is always about whose number it was in.

That has a practical consequence. Chasing scope gaps by reading subcontractor letters more carefully has a low ceiling, because the letters are usually not wrong — they are individually reasonable and collectively incomplete. The gap only becomes visible when you lay every trade's inclusions and exclusions side by side against the master scope and look for the work that appears in nobody's column.

That comparison is mechanical, tedious, and exactly the kind of thing worth automating. It is also entirely doable by hand with a spreadsheet and a disciplined afternoon, which is genuinely the right answer on a small job.

Three things that help regardless of tooling

Write the interface matrix before you tender, not after. A one-page grid of who supplies and who installs, for every seam you already know about, removes the ambiguity before anyone prices it. It is the single highest-return hour in the buyout.

Treat “by others” as an unpriced item, not an exclusion. When you see it, the correct reflex is to find which other. If no letter claims it, you have just found a gap while it is still free to fix.

Keep the record between projects. The gap that cost you money on the last job will present itself again on the next one. Most shops rediscover the same handful of leaks every eighteen months because the knowledge left with the PM who learned it.

Where the local part matters

Roughly three quarters of this list travels anywhere. Hoisting responsibility, access panels, backing, cutting and patching and the mechanical/electrical seam are argued the same way in Calgary, Chicago or Milan.

The rest is genuinely local. Excess soil is a statutory Ontario problem with a specific regulation attached. Winter conditions are a function of the climate and the enclosure date. Green standard items depend on the municipality. If you are building outside the GTA, keep the structure of this list and replace those three or four rows with your own jurisdiction’s equivalents.