Short answer
How is a house set out on the plot before digging, and what should the owner check? Setting out marks the building's lines and points on the ground before excavation. IS 11134:1984 builds them in stages, from the primary points tied to the official system, to the secondary points, and then to the position points. Ask who sets out the layout, tie it to the approved plan and the boundaries, and keep the pegs safe. IS 11134 does not name a method for checking right angles. Ask the engineer or surveyor which check is used and to record it.
On this page (14)
- What does setting out mean?
- In what order is the layout built up?
- What are centre lines and the grid?
- Who sets out the layout?
- How is the layout tied to the official boundary?
- How are the points protected?
- How are the right angles and lengths checked?
- What do the model bye-laws say about the boundary lines?
- Inline image
- What should I check before digging?
- What mistakes should I avoid?
- Frequently asked questions
- Related guides
- Sources
Setting out is the step between the approved plan and the first spade of earth. It puts the building’s lines and corners on the ground, so that the trenches and walls go where the plan says. A mistake here is hard to undo once the foundation is cast. This page explains what the Indian setting-out code IS 11134 says, what the model bye-laws say about the boundary lines, and what an owner should check before digging.
It gives no excavation depth, footing size or tolerance. Those are for the engineer and the plan.
What does setting out mean?
IS 11134 says the purpose of setting out is “to indicate the position of proposed features” (foreword 0.2). It contrasts this with land surveying, which fixes the position of existing features. The standard does not define “setting out” in its definitions, so the plain meaning is the one above.
The standard covers the measuring of the primary framework on the site, the setting out of reference lines (base lines), the transfer of those lines to other floors, the setting out of position points, and the levelling for each (clause 1.1).
In what order is the layout built up?
Clause 3.1 describes the order. The setting out starts at points in the official or agreed coordinate system. For a large project, a local framework of primary points may be needed. From the primary points, secondary points are set out, and some of them form the base lines. The position points, such as columns and walls, are then set from the secondary system.
The standard describes this as stages, but does not list the four stages in the text read. The order is what matters: the outer points first, then the lines, then the individual wall and column positions.
| Point | What IS 11134 says (wording only) | Clause |
|---|---|---|
| Purpose | Indicate the position of proposed features | 0.2 |
| Scope | Primary framework, base lines, transfer to other floors, position points, levelling | 1.1 |
| Primary point | Fixed by measurement, referred to the official or agreed system | 2.1 |
| Secondary point | Reference point for setting out position points | 2.2 |
| Position point | Marks the position of a detail of a building | 2.3 |
| Check measurement | Independent measurement to check a previous one | 2.8 |
| Who sets out | Qualified personnel for primary; engineer or surveyor for secondary; foreman for position points | 3.1 |
| Instrument | Checked before first use and re-checked frequently | 11.3 |
Source: IS 11134:1984, clauses as listed. Tolerances are not reproduced.
What are centre lines and the grid?
IS 11134 does not define a centre line in plain words. Clause 9(b) says that the centre lines of the structural elements, which together form the structural grid, are normally established with reference to base lines, and that the grid locates the structural elements of the building. So the centre line of a wall is the line the trench and the wall are set from, and the base lines are the lines the centre lines are set from.
Clause 9(c) describes a location grid, where each square of the grid is set out from one grid station as a reference point and one grid line as a reference direction. The standard does not call this a pillar. The reference pillar is a practice term for the fixed mark from which the layout is measured.
Who sets out the layout?
Clause 3.1 gives the division of work. The establishment of primary systems should be entrusted to people with the relevant professional qualifications. For the secondary and lower-order systems, an engineer or surveyor with detailed knowledge of building survey techniques should be engaged. The setting out of position points can usually be done by a foreman on the site.
The standard does not say who checks the layout or who signs the record. Ask for both in writing.
How is the layout tied to the official boundary?
Clause 3.1 says that the connection of the primary system to the official co-ordinate system is carried out in consultation with the survey department of the local authority. Clause 6.3 says that the information about suitable points in the official system is obtained from the appropriate authority. Clause 9(c) says that the appropriate authority should be consulted before the setting out is done against a location grid, because the grid can show the legal boundaries, building lines and street axes.
For an owner, this means the layout should tie to the approved plan and the boundary, not to a peg chosen on site.
How are the points protected?
Clause 6.5 says primary points shall be marked so that displacement from outside action, frost movement and similar causes is prevented as far as possible, using precise marking such as punch marks. It also says primary points should, where possible, be placed outside the working zone. Clause 10.4 says a transferred point should be marked straight after the measurement so that it does not move.
The standard speaks of primary points. The same protection applies to any peg or pillar that holds a line through the digging, and that is practice.
How are the right angles and lengths checked?
IS 11134 requires checked distances and checked angles between the secondary points and between the position points (clauses 7.3.2 and 8.2). It requires that the tape conforms to IS 1269 and is corrected for temperature, sag, slope and tension (clause 4.1). It requires the instrument to be checked for accuracy and stability before its first use, and says it should be re-checked frequently afterwards (clause 11.3).
The standard does not name a method for the right angle. The 3-4-5 method and the equal-diagonal check are common practice on Indian sites. They are not in IS 11134. Ask the surveyor which method is used and to record the check.
What do the model bye-laws say about the boundary lines?
The Model Building Bye-Laws 2016 define the set-back line as a line, usually parallel to the plot boundaries or the centre line of a road, laid down by the authority or by the master plan. Nothing may be built towards the plot boundary beyond it without the authority’s permission. The building line is the line up to which the plinth of a building adjoining a street may extend (definitions).
The site plan submitted for permission shows the boundaries of the site, the street, the existing buildings and the proposed building (clause 2.10.1). The architect’s declaration states that the mandatory set-backs will be kept as marked on the layout plan (declaration item 13). So the layout on the ground should match the set-backs on the plan. The owner can ask for those set-back lines to be pegged out before digging.
State rules and layout approvals can differ from the model. Check the sanctioned plan and your local bye-laws.
Inline image
What should I check before digging?
These checks are practice. They are not steps in IS 11134.
- Find the boundary markers on the ground and check them against the sale deed and the survey.
- Check the layout against the sanctioned plan, including the set-back lines and the building line.
- Ask who set out the layout and who signed the record. The standard says an engineer or surveyor with detailed knowledge of building survey techniques should be engaged for the secondary systems, and the owner should see the record.
- Check the corners. Measure the diagonals and ask how the right angle was checked.
- Keep the pegs and the reference points clear of the digging. Ask for offset pegs or frames set outside the trench, so the layout can be put back after the excavation.
- Check the lines again after heavy rain or when the pegs are disturbed.
What mistakes should I avoid?
These are practice points, with the standard clause that touches them where there is one:
- Setting the layout from a moved peg. Levels and lines must come from the fixed points (IS 11134 clause 6.5 on protecting points).
- Setting the building in from the wrong boundary. Check the set-back lines against the plan and the boundary.
- Corners that are not square. The standard requires the corner points to be set out carefully, but it does not name a method. Check the diagonals.
- A reference pillar disturbed by the excavation. Keep it outside the working zone where possible.
- No record of the layout. Without it, the position of the foundation cannot be proved later.
Frequently asked questions
Who fixes the first point on my plot?
The standard says the primary points are tied to the official or agreed system, in consultation with the local authority’s survey department. In practice, the engineer or surveyor does this and the owner sees the record.
Does IS 11134 give the 3-4-5 method?
No. The standard requires checked distances and angles, but it does not name a method for the right angle. The 3-4-5 method is common practice.
Is my plot’s set-back line the same as the building line?
No. The set-back line is the line parallel to the boundary beyond which nothing may be built towards the boundary. The building line is the line up to which the plinth may extend towards a street. Your plan shows which applies.
Do I need a licensed surveyor for a small house?
The standard says an engineer or surveyor should be engaged for the secondary and lower-order setting out. For a small plot, ask the engineer who sets the layout and how it is checked.
Related guides
- GL, PL, FFL, NGL and FGL: what the level marks on a house drawing mean
- Plot checks before buying: slope, drainage, soil, road and flood risk
- Before the footing concrete: an owner’s checklist for pit and steel
This guide is general information. Read the disclaimer. Your engineer, your surveyor and the local authority decide the layout and the set-backs for your plot.
Sources
- IS 11134:1984, Code of Practice for Setting Out of Buildings. Clauses 0.2, 1.1, 2.1 to 2.3, 2.8, 3.1, 4.1, 6.3, 6.5, 7.3.2, 8.2, 9(b), 9(c), 10.4 and 11.3 read from the archive.org text. Tolerances are not reproduced. Edition 1984, reaffirmed 2000; current status to be confirmed on BIS.
- Model Building Bye-Laws 2016 (MoUD/TCPO), definitions of set-back line and building line, clauses 2.10.1 and 2.11.2, and the architect's declaration form (Appendix A-5). Model text; states adopt their own bye-laws.
General information only. It is not a structural design or professional advice. Ask a licensed structural engineer or architect to check your plans and site.