Building condition audit
Structural Audit of Buildings and Plants
Visual inspection, NDT and core testing of RCC frames, with a report that grades each defect and sets repair priorities.
Quick AnswerA structural audit checks a building’s columns, beams, slabs and walls by visual survey and non-destructive testing, confirms strength with cores where needed, and grades each defect with a repair priority. It suits older, distressed or altered buildings. Before any core is cut, the bars are located; see what we do: concrete scanning.
What is a structural audit?
A structural audit is a systematic check of a building's frame (columns, beams, slabs, walls and foundations as far as they can be seen) to judge whether it is still safe for its use, and what repair it needs. It combines a careful visual survey, non-destructive tests on the concrete, a few cores where needed, and an engineer's assessment, set out in a report with each defect located and graded.
An audit is not a demolition notice or a guarantee. It records the condition on the date of inspection and tells the owner what to fix, in what order, and what to watch. Most of our audits are of reinforced concrete buildings: housing societies, commercial blocks, schools, hospitals, warehouses and industrial plants.
When should a building be audited?
When it is old, when it shows distress, when its use or load is about to change, or when something has happened to it.
- Age: many municipal bodies ask owners of older buildings to submit a structural audit at intervals; check the bye-laws that apply to your property.
- Visible distress: wide or growing cracks, spalled concrete with rusted bars showing, rust stains, leaking slabs, sagging beams, tilting walls.
- Change of use or extra floors: a warehouse converted to a factory, a terrace given a water tank or a new storey.
- After an event: fire, flooding, a vehicle impact, a nearby excavation or an earthquake.
- Before purchase or lease: buyers of older plants and buildings want to know what repairs they are inheriting.
For buildings in higher seismic zones, IS 15988:2013 gives the Indian guidelines for seismic evaluation and strengthening of existing reinforced concrete buildings, and an audit can be scoped to provide the inputs that evaluation needs.
How is the audit carried out?
In five stages, from paperwork to report, with testing only where the visual survey says it is needed. Our crews carry two company-owned NDT kits, each with a rebound hammer, an ultrasonic pulse velocity tester, a cover meter and a core cutter.
- Records: structural and architectural drawings, the age of the building, past repairs and any earlier audit.
- Visual survey: every accessible member is inspected, and cracks, spalls, dampness and exposed steel are marked on floor plans with photos.
- NDT: tests are run on representative and suspect members to compare concrete quality across the building.
- Cores and chemistry: where strength must be confirmed, cores are cut and tested; carbonation depth is checked on fresh cores by phenolphthalein spray.
- Assessment and report: results are interpreted against the drawings and loads, and repairs are prioritised.
Which tests are used, and to which standard?
Each test answers a different question, so an audit usually combines two or three of them rather than relying on any single reading.
| Test | Indian standard | What it tells you |
|---|---|---|
| Rebound hammer | IS 13311 (Part 2):1992 | Surface hardness; compares concrete between members |
| Ultrasonic pulse velocity | IS 516 (Part 5/Sec 1):2018, which replaced IS 13311 (Part 1) | Uniformity, cracks, honeycombing and voids inside |
| Cover meter | Used with design drawings | Bar location, spacing and concrete cover |
| Core test | IS 516 (Part 4):2018 | Actual in-place compressive strength |
| Carbonation depth | Phenolphthalein indicator on fresh concrete | Whether steel has lost its alkaline protection |
Table note: the audit is priced on built-up area in sq ft; if your papers give it in sq m or gaj, Land Area Converter, in short, does the conversion.
The rebound hammer only reads the outer few centimetres, so it is a comparator, not a strength meter on its own. The CPWD Handbook on Repairs and Rehabilitation of RCC Buildings groups these methods by purpose: strength, chemical attack, corrosion risk and integrity, and our test plans follow the same logic.
Why scan the concrete before coring?
Because cutting a main bar to test the concrete around it does more harm than the test is worth. Before cores are drilled, we locate the reinforcement with a cover meter or radar so the core lands between bars; see what we do: concrete scanning. In slabs carrying conduits or post-tensioned cables, a full radar scan is safer still; our page on RCC slab scanning explains how cables and pipes are mapped in the slab.
Radar also helps where the audit suspects hollow areas: voids under floor slabs on settled fill, or gaps behind retaining walls. Read void detection at a glance for how those are found without breaking the floor.
What do common cracks and stains usually point to?
Patterns matter more than any single crack; the audit reads them together with the tests before drawing a conclusion. A few patterns we meet again and again in Indian RCC buildings:
- Cracks along the line of a bar, with rust stains: usually corrosion of the steel pushing the cover off, common on slab soffits under toilets and terraces.
- Fine random map cracking on plaster: often shrinkage of the finish, not a structural problem, though it lets water in.
- Diagonal cracks in walls near corners and openings: may come from settlement or movement of the frame and deserve a closer look at the foundation.
- White deposits on walls and slabs: efflorescence from water passing through, a warning sign for corrosion further on.
- Visible sag in beams or slabs: overload, poor original concrete or loss of steel area; this goes straight to the urgent list.
None of these is a diagnosis on its own. A crack gauge fixed across a suspect crack and read over a few weeks also shows whether it is still moving.
What does the report contain?
A plain-language summary for the owner, and the evidence behind it for the engineer.
- Building description, drawings reviewed and limits of the inspection
- Defect plans floor by floor, with photo references and crack widths
- NDT and core results by member, with locations
- Condition grading of members and an overall view of the building
- Repair priorities: immediate safety action, short-term repair, long-term maintenance
- Repair methods suited to each defect, and where a detailed retrofit design is needed
Defects are marked on measured floor plans. If no reliable drawings exist, the Mezux as built survey crew can draw the building first, which also gives the repair contractor accurate quantities.
Structural audit rates – November 2026
A structural audit is ₹5 per sq ft of built-up area, with a minimum of ₹50,000; core tests are extra. The rate covers the visual survey, NDT and the report. GST is extra.
- A 30,000 sq ft commercial block: 30,000 × ₹5 = ₹1,50,000
- A 6,000 sq ft house or small shed: ₹30,000 by area, so the ₹50,000 minimum applies
- Cores: charged per core in the quote, including laboratory testing
- Any mobilisation or travel cost, if applicable, is stated in the quote
Some municipal bodies accept audits only from engineers on their own list. If your audit is for such a filing, tell us at enquiry so we can confirm before you order. In Delhi NCR a team can usually start the same day or within 1 working day, and elsewhere in India a locally based engineer begins immediately or within 1 working day; the report date depends on building size and core testing and is stated in the quote. Share the address, built-up area and the reason for the audit, then check rates for your site.
Frequently asked questions
How often should a building get a structural audit?
It depends on age, condition and local bye-laws. Older buildings and those showing distress should be checked at regular intervals and after any major event.
Will the audit damage my building?
Most tests are non-destructive. Cores leave small holes that are filled with repair mortar the same day.
Can you audit a running factory?
Yes. We plan around shifts and safety rules. If you also need buried services mapped on the premises, see booking underground utility mapping for factories.
Do you also design the repairs?
The report recommends repair methods and priorities. A detailed retrofit design, where needed, is a separate engineering job.
Is a rebound hammer test enough on its own?
No. It reads only the surface and is best used to compare members; cores or UPV are needed to support any strength conclusion.
Do you audit steel structures?
Our NDT kits are set up for concrete. For steel sheds we carry out visual and dimensional checks; tell us the structure type at enquiry.
Get a written quote for a structural audit
Concrete and buildings
Written by Saniya Parveen · Technically reviewed by Rahul Rai · Updated 8 November 2026