You’ve done everything right. You shortlisted a project, visited the site, liked the sample flat, and checked that it’s RERA registered. But there’s one thing most buyers completely skip and it could cost you years of daily discomfort, or worse, crores in losses. RERA requires builders to upload approved building plans and drawings for every registered project. Most buyers glance at them, feel confused by all the technical lines and numbers, and move on. That confusion is understandable these drawings are highly technical documents designed for engineers, not buyers. But here’s the thing: those drawings are a goldmine of information. You just need to know where to look. As a civil engineer who advises first-time and elderly home buyers, here’s how I analyze approved building plans before giving any recommendation.
The Staircase Test: Is It Actually Safe to Climb Every Day? Many buyers especially seniors specifically choose the 2nd, 3rd, or 4th floor. The logic is simple: low enough to use the staircase comfortably if the lift fails or during an emergency. But not all staircases are built equal. From the approved drawings, you can extract the tread and riser dimensions for the staircase. Here’s a real example:
Riser = 158 mm
Tread = 250 mm
There’s a formula called Blondel’s Law used by engineers to check whether a staircase is comfortable and safe:
2R + T
So: 2 * 158 + 250 = 566 mm
As per Blondel’s Law, this value should ideally fall between 600 and 650 mm. The purpose of this formula is to ensure step geometry matches normal human walking mechanics reducing fatigue and minimizing the risk of tripping. At 566 mm, this staircase falls below the recommended comfort range. An elderly person using this staircase daily is being set up for cumulative fatigue. It won’t show in the sample flat. It won’t come up during the negotiation. But it will show up every single morning for the next 20 years.
The Parking Clearance Trap: Will Your Future Car Actually Fit? Now look at the car parking elevation drawing. In this project, the floor-to-ceiling height of the parking level is shown as 2.2 metres.
Here’s the calculation:
2.2 m – 0.15 m (slab depth) = 2.05 m clear height
If you currently drive a small hatchback or a sedan, you won’t face any issue with this clearance today. But think ten years ahead. As your family grows, your income grows, and your needs change many buyers eventually upgrade to a larger vehicle. An SUV like a Fortuner stands at 1.835 m, leaving only 21.5 cm of clearance under a 2.05 m slab. Add a roof carrier, a luggage rack, or any roof accessory, and your upgraded vehicle physically cannot enter the parking bay you paid for. Your parking allotment is fixed for the lifetime of the property. Your car doesn’t have to be.
The Swimming Pool Above the Office: A ₹2 Crore Risk Nobody Talks About
Here’s one that most buyers never even think to check. In the layout drawing of this project, there is a swimming pool located directly above Office No. 102. If you’ve purchased that office at ₹2 crore or more you are now living with two permanent risks:
- Waterproofing failure. Pools require robust waterproofing that needs periodic maintenance. If that membrane fails even slightly, the first space to get water seepage is the office directly below. Repairs will be your headache, not the builder’s.
- Constant slab impact noise. Swimmers, footfall on the pool deck, filtration equipment vibrations all of it transmits through the slab into your office. This is not something you’ll experience in a site visit. But it will follow you into every client meeting. These are the details that separate an informed investment from an expensive mistake.
This is exactly the kind of analysis I do during a pre-purchase property evaluation. Most buyers never think to look at these drawings and builders are counting on that. Before you finalize any flat, run these checks. If the technical drawings feel overwhelming, that’s what I’m here for. Reach out for a consultation the fee is a fraction of what a wrong decision will cost you. All awareness content on concretetruths website is completely free.