Setting out on site
Construction Survey and Site Layout Services
Control, grid layout, levels and check surveys from excavation to handover, by crew-day or with a full-time site surveyor.
Quick AnswerA construction survey sets out the design on site (control points, grid lines, footings, columns and levels) and checks each stage as it is built, ending with an as-built record. Total stations do most of the work, with auto levels for heights. To see where the instrument fits, read when you need a total station survey.
What is a construction survey?
A construction survey puts the design on the ground and keeps it there. It marks every grid line, footing, column, wall, road and drain, sets their levels and checks them as the work rises. The marking part is called setting out or stake-out. Done well, it is invisible; done badly, it shows as a column 80 mm off grid or a drain falling the wrong way.
On a construction site survey, work starts before the first excavator arrives and ends with a record of what was built. In between, the crew visits whenever a new element must be fixed.
The same discipline applies beyond buildings: machine foundations with anchor bolts to a few millimetres, warehouse floor levels over large areas, and township road centrelines pegged every few metres. Each has its own tolerance, but all construction layouts depend on one set of control used by everyone on site.
What does the surveyor do at each stage of the job?
The tasks change as the building grows, but each one ties back to the same control points fixed at the start.
| Stage | Survey task | What you get |
|---|---|---|
| Before work | Control points and site benchmark; check of existing levels against the design | Control sketch, level check note |
| Excavation | Excavation lines, formation levels, cut quantities | Pegs on site, level sheet |
| Foundations | Pile or footing centres, pedestal and plinth levels | Marked centres, check report |
| Frame | Column grid on each floor, slab and beam levels, verticality checks | Floor-wise marking, deviation list |
| External works | Roads, drains, boundary walls, gradients | Pegs and level marks at set intervals |
| Completion | Survey of what was built | As-built drawing |
Table note: most of these tasks use a total station; for how the instrument measures angles and distances, read the Mezux guide: total station.
How is a building grid set out?
A setting out survey works from coordinates, with a total station on one control point, a backsight on another and every key point checked from a second set-up.
Grid intersections are computed from the architect's or structural drawing and loaded into the instrument. The crew sets each point by angle and distance, then places offset pegs outside the excavation so they survive the digging, and the grid is re-strung from them later. Before your engineer accepts a layout, we tape diagonals and cross distances, and any mismatch is explained before concrete is poured.
A good layout starts with good questions about the drawings, the reference lines and who approves the marking; we list them under questions to ask before a building layout survey.
How accurate is the setting out?
The instruments can work to millimetres; on site, control, procedure and checking set the limit. Our six total stations are rated at 5 mm + 3 ppm for distance, and our six auto levels close within ±2.5 mm per km. Four DGPS base station and rover sets hold 1–2 cm horizontally for control on large plots and long roads.
- Control points go where traffic and stockpiles will not disturb them, and are re-checked at intervals.
- The site benchmark is tied to your project datum or a nearby known benchmark.
- Levels and spot levels are carried by closed loops, so any error shows at the end of the run.
- Tolerances are agreed with your structural consultant first and printed on every check report.
The costly mistakes are seldom instrument errors. They come from a superseded drawing revision, a control peg knocked by a dumper and not re-checked, or two contractors on two grids. We record drawing number and revision on every layout sheet, re-observe control before each major pour and keep one control list for the site.
What must be checked before digging?
The ground under the layout: buried cables, pipes and old foundations. A footing set out perfectly over a live HT cable is still a problem, so the marked area can be scanned with radar and locators; see details of pre-excavation scanning. Existing levels need checking against the design too, because a higher or lower site changes cut and fill and sometimes the plinth level.
Boundaries deserve the same care. A building set out from a wall a metre inside the true plot line loses area, while one a metre over it invites a dispute. Where corners have never been surveyed, we fix them first and show the layout against them on the site plan, so setbacks run from the right line.
How can you hire a survey crew, and what does it cost?
Either by the crew-day for visits as needed, or as a full-time site surveyor for busy phases. Rates are exclusive of GST.
- Construction survey crew with instrument: ₹8,000 per crew-day
- Full-time site surveyor with instrument: ₹1,20,000 per month
- Example: 12 visits in a month cost 12 × ₹8,000 = ₹96,000; at 15 or more visits a month, the full-time surveyor works out cheaper
- Any applicable mobilisation/travel cost is shown in the written quote
Many projects use crew-days during excavation, a full-time surveyor while floors go up and crew-days again for external works; the quote fixes the figure for your programme. A crew-day is a working day on site with the instrument, and any late-pour overtime is agreed in advance, not added later.
What happens at the end of construction?
The building is surveyed as built, so the owner, the authority and the next contractor have a true drawing. Positions of walls, columns, services and external works are measured and compared with the approved design; you can read more about as built survey and what it covers. Deviations found during construction are already in our check reports, so the as-built drawing is quicker to produce and easier to trust.
How soon can a crew come, and where do we work?
In Delhi NCR a crew reaches site the same day or within 1 working day of a call. Elsewhere in India, a surveyor based in that city starts immediately or within 1 working day. Running sites get a standing weekly day, plus extra days when a pour is due. Check reports are issued the same day for small layouts and within 3 working days for larger surveys. We take building, factory, warehouse, road and township work across India. Share the drawings, site address and programme, and enquire about a survey for your project.
Frequently asked questions
What is the difference between setting out and a construction survey?
Setting out is the marking part. A construction survey also covers control, level checks, deviation reports and the final as-built record.
Do I need a topographic survey before construction starts?
In most cases, yes, to confirm existing levels, contour lines and features against the design; read more about topographic survey.
Can you check a contractor’s layout instead of doing it?
Yes, we set up independently and measure the marked points, then give a deviation list against the drawing.
Do you give a full-time surveyor for a high-rise?
Yes, with instrument, at a monthly rate. The surveyor works to your site timings and reports to your project engineer.
Which drawings do you need?
The latest approved centre-line or grid drawing, the site plan with reference points, and the level drawing. Revisions must be shared as soon as they are issued.
Can you set out roads and drains in a township?
Yes, we set centrelines, edges and levels at fixed intervals with total station and GPS receiver, and check gradients so drains fall the right way.
Get a written quote for a construction survey
Before and after building
Written by Saniya Parveen · Technically reviewed by Rahul Rai · Updated 8 November 2026