Worked examples
Every figure computed
Real jobs, estimated end to end
A deck, a roof, a slab, a bathroom: each job from the first tape measurement to the bill of materials, with the calculators run in the order the work is done and every decision shown — the waste allowed, the reason for it, and where the estimate is most likely to be off.
- 18Jobs worked through
- 158Takeoff steps, in order
- 146Figures computed
Measured first
Each page opens with what was measured and how — and the mistake that makes each measurement wrong — because every quantity after it is only as good as the tape.
Taken off in order
The steps run in the order the work is done, and each says what it needs from the one before. Getting the order wrong is how a list looks complete and is short in two places.
Honest about the error
Every page ends with where its estimate is most likely to be wrong, which way, and why — the mechanism, not an invented overrun, because these jobs are modelled rather than recorded.
6 jobs
Bathrooms and interiors
Where the background decides the product and the finished thickness decides the order, the tile layout decides the waste, and the smallest lines — beads, trims, edge profiles — are bought in whole lengths rather than metres.
Bathroom gutted and retiled
UK · metric firstA 3 × 4 m bathroom, gutted to studs, reboarded and retiled
9 steps · 7 figures computed · 5 places it can be wrong
See every step →A room replastered
UK · metric firstA 4 × 3 m room replastered — board and masonry walls, ceiling included
6 steps · 6 figures computed · 4 places it can be wrong
See every step →Bedroom repaint
US · imperial firstA 12 × 14 ft (3.7 × 4.3 m) bedroom with an 8 ft (2.4 m) ceiling repainted: walls from deep charcoal to off-white, ceiling and trim white like for like
7 steps · 7 figures computed · 6 places it can be wrong
See every step →Vinyl plank floor
US · imperial firstLuxury vinyl plank laid through a 15 × 20 ft (4.6 × 6.1 m) living room and a 4 × 12 ft (1.2 × 3.7 m) hallway on a concrete slab, as a floating floor broken at the hallway neck
7 steps · 7 figures computed · 5 places it can be wrong
See every step →Basement room drywall
US · imperial firstA 12 × 20 ft (3.66 × 6.10 m) basement rec room hung and finished in drywall — 8 ft (2.44 m) walls, a soffit boxing the beam and duct down its length and a Level 4 finish
10 steps · 10 figures computed · 6 places it can be wrong
See every step →Stud partition with a door
UK · metric firstA 3.6 m (11.8 ft) timber stud partition, 2.4 m (7.9 ft) high, with a door, insulated for sound, boarded both sides and skimmed
10 steps · 10 figures computed · 5 places it can be wrong
See every step →
3 jobs
Roofs and lofts
Where the largest quantity is decided by the smallest one — the pitch sets the true area, and the outlets, eaves and ridge set everything laid on it — and where a loft's target is a performance figure, not a thickness.
Flat roof recovered
UK · metric firstA 40 m² (431 sq ft) flat roof stripped and recovered, warm-roof build-up
8 steps · 3 figures computed · 4 places it can be wrong
See every step →Shingle roof replacement
US · imperial firstA 30 × 40 ft (9.14 × 12.19 m) gable roof at 6/12, torn off to the deck and reroofed in architectural asphalt shingles
11 steps · 10 figures computed · 6 places it can be wrong
See every step →Loft insulation top up
UK · metric firstA 7 × 9 m (23 × 29.5 ft) loft topped up from 100 mm to 270 mm (3.9 to 10.6 in) of mineral wool, with a boarded storage area and the cistern pipework lagged
7 steps · 7 figures computed · 6 places it can be wrong
See every step →
3 jobs
Groundworks, slabs and driveways
Where the dig depth is a sum rather than a choice, and where one material cannot be topped up an hour later.
Garden room slab
UK · metric firstA 6 × 4 m ground-bearing slab for a garden room, setting out to curing
9 steps · 7 figures computed · 5 places it can be wrong
See every step →Concrete driveway replaced
US · imperial firstA 12 × 50 ft (3.7 × 15.2 m) single-car concrete driveway broken out and repoured at 4 in (102 mm) on a compacted gravel base
10 steps · 10 figures computed · 5 places it can be wrong
See every step →Gravel driveway
UK · metric firstA 6 × 10 m (19.7 × 32.8 ft) gravel driveway on 150 mm (5.9 in) of open-graded crushed stone over a geotextile, with a block edge
8 steps · 8 figures computed · 5 places it can be wrong
See every step →
3 jobs
Patios and garden walls
Where the levels come before the materials: the fall, the base and the footing decide the order long before the first paver or brick is counted.
Paver patio
US · imperial firstA 12 × 16 ft (3.7 × 4.9 m) concrete paver patio against the house, on 4 in (102 mm) of compacted base and 1 in (25 mm) of bedding sand, with polymeric sand joints
10 steps · 10 figures computed · 6 places it can be wrong
See every step →Block retaining wall
US · imperial firstA 40 ft (12.19 m) segmental block retaining wall, 3 ft (0.91 m) exposed plus one buried course, with drainage stone and a perforated heel drain laid to fall
11 steps · 11 figures computed · 7 places it can be wrong
See every step →Brick garden wall
UK · metric firstA 10 m (32 ft 10 in) one-brick garden wall, its brickwork 1.2 m (3 ft 11 in) out of the ground on average under the coping, on a concrete strip footing stepped down a sloping garden
8 steps · 8 figures computed · 6 places it can be wrong
See every step →
2 jobs
Decks and fences
Where the frame is the quantity nobody sees: the spans, posts and footings are taken off first, and the boards and pickets follow from them.
Attached deck
US · imperial firstA 16 × 12 ft (4.9 × 3.7 m) pressure-treated deck, 3 ft (0.9 m) off grade and ledgered to the house, with one stair and a railing on three sides
11 steps · 10 figures computed · 5 places it can be wrong
See every step →Privacy fence
US · imperial first150 ft (45.7 m) of 6 ft (1.83 m) wood privacy fence on 4x4 posts at 8 ft (2.44 m) centres, with one walk gate, on a gently sloping yard
7 steps · 7 figures computed · 6 places it can be wrong
See every step →
1 job
Circuits
Where the load decides everything after it: the breaker, the conductor, the voltage drop and the conduit each take the previous answer as their input.
Electric vehicle charger circuit
US · imperial firstA 48 A Level 2 EV charger, hardwired on a new 240 V circuit run 45 ft (13.72 m) in 3/4 in EMT from a 200 A panel to an attached garage
9 steps · 8 figures computed · 5 places it can be wrong
See every step →
Your own job
Run the same chain with your measurements
A takeoff asks for each measurement once and runs every calculator a job needs; My Project turns the results into a bill of materials you can export.
Figures that are re-run, not typed
Each page's numbers come from the calculator its step names, checked every build.
Both unit systems
Modelled in one market's units, with the other system in brackets throughout.
No prices
Quantities only: a price is yours to enter, and it never leaves your device.
Frequently asked questions
- What is a worked construction estimate?
- One job taken from the first measurement to the bill of materials, in the order the work is done: what was measured and how, which calculator produces each quantity and what it needs from the step before, the waste allowed on each material and why, and where the estimate is most likely to be wrong.
- Are these real jobs?
- No, and each page says so at the top. They are modelled: every figure is computed by the calculator the step names and re-run whenever the site is built, but no job was carried out, so nothing is presented as a measured overrun.
- Can I run the same takeoff with my own measurements?
- Yes. Every step links the calculator it uses, and most jobs also exist as a takeoff that asks for each measurement once and runs the whole chain; the results can be sent to My Project and exported as a bill of materials.
- Why are some examples in feet and others in metres?
- Each job is modelled for one market — the United States in imperial units, the United Kingdom in metric — because product sizes and codes differ, not just units. Every figure gives the other system in brackets.