What Is an As-Built Survey and When Is It Required in Construction

An as-built survey is one of those types of geodetic work that people think about at the last minute. It usually happens when the contractor has already finished, the supervisory authority is demanding documentation, and the as-built record simply does not exist. Below we explain what this work involves, when it needs to be done, and what happens if it is skipped.

What an As-Built Survey Is

An as-built (or as-built geodetic) survey is the geodetic recording of the actual position of completed construction elements: buildings, structures, utility networks, roads, and landscaping features. In essence, it answers the question: “What was built, and exactly where?”

The result is an as-built plan (drawing) showing the coordinates and elevations of the structures as actually constructed. This is compared against the design position, and any deviations are recorded in the documentation.

Regulatory basis in Kazakhstan:

• SP RK 1.04-103 “Geodetic Work in Construction” — the primary standard;
• SN RK 1.04-08 “Acceptance into Service of Completed Construction Projects”;
• GOST 21.101 — requirements for the composition and presentation of as-built documentation.

What Appears on an As-Built Plan

The scope of the survey depends on the type of facility and the stage of construction. Typical content:

Buildings and structures:

• axes and elevations of foundations (pile caps, monolithic slabs);
• actual dimensions and floor elevations of each storey;
• elevations of floor slabs, roof, and finished floors;
• position of columns, walls, and openings.

Utility networks (underground):

• routes of water supply, sewerage, heat mains, gas pipelines, cables;
• depth of cover at break-points and every 20–50 m;
• invert elevations at manholes;
• coordinates of all manholes, gate valves, and branch connections.

Roads and landscaping:

• elevations of paved surfaces, kerb lines, embankment slopes;
• gradients of drainage channels;
• position of street furniture and amenity structures.

Linear features (pipelines, cables):

• route with coordinates of turning points;
• depth every 50 m and at crossings with other services;
• composition of valve and fitting assemblies.

When an As-Built Survey Is Conducted

The key rule: an as-built survey must be carried out before trenches are backfilled and structures are enclosed — while what has been built can still be measured. After that, it is too late.

In practice this means several distinct “windows”:

Before Backfilling

Underground networks — water supply, sewerage, cables, pipelines — are surveyed immediately after laying and testing, but before the trench is backfilled. This is the most critical moment. Missing it means either re-excavating the trench or producing unreliable documentation from memory.

After Foundation Construction

The set-out axes and actual position of the foundation are recorded before wall construction begins. This allows any displacements that will affect subsequent work to be identified early.

After Each Floor Slab

On multi-storey structures, the slab elevations and actual position of structural elements on each floor are surveyed. Accumulated vertical deviations affect the accuracy of upper floors.

Before Handover

A final as-built survey of the entire facility is carried out before the completion acceptance certificate is signed. At this stage the definitive position of all elements — including landscaping — is recorded.

Summary Table: Who Orders and When

Construction stage	What is surveyed	Who orders
Underground network laying	Route, depth, fittings	General contractor
Foundation construction	Axes, elevations, dimensions	Technical supervision / developer
Each floor	Slabs, columns, walls	Technical supervision / developer
External networks	Routes, manholes, elevations	General contractor
Roads and landscaping	Elevations, geometry	General contractor
Final acceptance	Entire facility	Developer / technical supervision

As-Built Documentation: What the Package Includes

On completion of the survey, the surveyor prepares:

1. As-built plan — a drawing showing the actual position of all elements plotted on a topographic base.
2. Set-out control scheme — the points and lines from which set-out was carried out.
3. Deviation schedule — a table of allowable and actual deviations from design position.
4. Coordinate and elevation register — points with coordinates in the national system (SK-42 or WGS-84).

All materials are delivered in DWG (AutoCAD) and PDF formats and are signed by the surveyor with their certification details stated. In Kazakhstan, the surveyor performing an as-built survey must hold a cadastral engineer’s qualification certificate.

Allowable Tolerances under SP RK

Type of work	Allowable deviation
Foundation axis position	±10 mm
Foundation elevation	±15 mm
Column position	±5 mm
Floor slab elevation	±10 mm
Underground network route in plan	±100 mm
Network depth of cover	±50 mm
Road surface elevation	±10 mm

If actual deviations exceed the allowable values, the developer is required either to prepare a concealed-works record with justification or to instruct the contractor to remedy the defects.

What Happens If an As-Built Survey Is Not Done

Inability to commission the facility. The architectural and construction control authority (MAASP or the local architecture and construction department) will not sign the acceptance certificate without a complete as-built documentation package. The facility cannot be commissioned, registered, or lawfully used.

Problems in the event of failures. If an incident occurs — a pipe burst, foundation settlement — the absence of as-built documentation shifts all liability onto the contractor. Without recorded actual elevations it is impossible to demonstrate that work was carried out in accordance with the design.

Difficulties during reconstruction. Five to ten years later, during reconstruction or network maintenance, contractors will not know the exact routes and depths. They will have to excavate blind or commission a cable-and-pipe locating survey — expensive and time-consuming.

Risks in a property sale. A buyer or bank providing mortgage finance will review the technical documentation. The absence of an as-built survey is grounds for a price reduction or refusal to proceed with the transaction.

How to Organise an As-Built Survey in Practice

Include it in the contractor’s agreement. Responsibility for calling the surveyor in good time before trench backfilling should be written into the construction contract. Otherwise, the contractor will backfill before the surveyor can arrive.

Identify “survey trigger points” in advance. At the construction organisation plan (COP) stage, mark the moments when a surveyor must be called: laying of each type of network, pouring of the foundation concrete, casting of each floor slab.

Work with a single survey contractor. If one surveyor carried out the set-out and a different one performs the as-built survey, discrepancies in coordinate systems and documentation conflicts are inevitable.

As-Built Surveys in Aktau

We carry out as-built geodetic work on projects in Aktau, Zhanaozen, and across Mangystau Region. We work both as part of full construction supervision (from axis set-out to final survey) and on individual stages.

For oil-and-gas facilities — pump stations, tank farms, wellhead tie-ins — we prepare as-built documentation in accordance with the specific requirements of the facility operator (CNPC, KazMunayGas, Chevron). We are familiar with the document submission standards at individual fields.

Summary

An as-built survey is not a formality — it is a safeguard for everyone involved in construction. The developer gets proof that the facility was built to the design. The contractor is protected against unsubstantiated claims. The acceptance authority sees the complete picture.

It must be done during construction, not afterwards — otherwise you face either re-excavation or backdated paperwork, both of which carry legal consequences.

If you need an as-built survey in Aktau or on a Mangystau Region project, contact us. We can dispatch a crew on the day of the call.