Pavers and precast blocks made with LC3, a cement that needs less clinker
TL;DR Lowclinker is a precast yard that makes pavers, kerbs and solid blocks with limestone calcined clay cement (LC3) in place of ordinary Portland cement. Developers with carbon targets and public works departments are the buyers. It works if the blocks pass the same tests at the same price and come with a carbon figure for every batch.
India made 453 million tonnes of cement in FY25[1]. Most of the carbon comes from clinker, and India's average cement still holds about 0.71 tonnes of clinker per tonne[2].
Builders who have set carbon targets struggle to buy anything better. One large Mumbai developer, which wants to cut embodied carbon per square metre by about a third by 2030, says it can't get LC3 beyond small trials and is negotiating for just 1,000 tonnes[2].
Plain precast items like pavers and kerbs are an easy place to start, because they need modest strength and are bought in volume. Yet the local yards that make them sell on price and have no carbon data to offer.
First, the important bit - Lowclinker makes non-structural precast concrete products to BIS standards. It makes no reinforced or load-bearing members.
LC3 swaps about half the clinker for calcined clay and limestone. A typical blend is 50% clinker, 30% calcined clay, 15% limestone and 5% gypsum, with up to 40% lower emissions than OPC[3]. It was conceived at EPFL and developed in India with IIT Delhi, IIT Madras and TARA, and BIS published IS 18189:2023 for it[4][3]. Lowclinker buys bagged LC3, tunes the mix for its presses and sells pavers with a test report and a carbon figure for each batch.
I reframed the seed, which proposed bio-rock grown by bacteria. That route is slow, gives off ammonia and can spend up to 60% of operating cost on growth media[5]. LC3 keeps the aim of less cement carbon in everyday building products, using kit a block yard already runs.
Developers pay through their contractors, by the square metre for pavers and per piece for blocks. Public works departments and smart-city projects buy through tenders. I found no published LC3 price or Indian paver price list, so collect local quotes before pricing. A premium for the carbon figure is an assumption to test, and my advice is to plan on winning at equal price first.
BIS published IS 18189 in 2023[4]. On 9 February 2026, a major cement maker launched LC3 commercially, after pilot runs that already made AAC blocks for a Swiss agency building in Delhi[6]. And in April 2025, a brief from a climate think tank, a developer and IIT Delhi named shortage of supply as the main block to uptake[2].
Nobody publishes a figure for LC3 precast in India. The clearest demand signal is one large developer seeking 1,000 tonnes for pilots and saying it can't buy enough[2]. Cement output of 453 million tonnes in FY25 is adjacent context only[1]. Supply is just opening, with one commercial launch so far[6].
That cement maker makes LC3 and has used it for AAC blocks in pilot work[6]. It's a likely supplier and could become a rival. The same developer is testing LC3 in its own concrete on its own township[2]. Biocement firms make biocement products abroad, the route this page set aside[8].
In my limited search I found no Indian yard selling LC3 pavers or blocks as a product.
| Difficulty | Moderate (50/100) |
| Starting capital | ₹1.3–2.5 Cr |
| Time to launch | 9–15 months |
The presses and curing are ordinary. The hard parts are a steady LC3 supply, mix tuning for early strength and admixtures, and a standards gap - the 2006 paver standard lists the cements it allows, and LC3 isn't among them[7]. Government tenders will follow that list until it changes.
Yes, you need permissions. It's a factory, and the products have to meet a standard.
Building this outside India? The categories above usually have a local equivalent, so check with your own regulator.
Don't let AI sign off strength or compliance. A lab test and a qualified engineer decide whether a batch passes, every time.
Want to work out the AI layer for Lowclinker? Talk to Yash →
Here's what can go south -
I think it's worth a look if you've run a precast or block yard and can sell to developers. Do not start with government tenders, honestly.
First, prove that LC3 pavers pass the M-30 test at the same cost as a nearby OPC yard, and get one developer with a carbon target to accept them on a live site.
Plan for roughly ₹1.3–2.5 Cr, covering presses, a curing area, a yard and working capital for cement stock.
Yes. You need pollution board consent for the yard, a factory licence and labour registrations, and your pavers have to meet the BIS standard buyers ask for.
Yes, if you can buy calcined clay cement locally at a fair price. Check your country's paver standards and environmental permits, which will differ from India's.
The free Lowclinker validation kit has the line-by-line capital breakdown, the effort scoring, the BIS and pollution-consent checklist, a 14-day validation sprint with pass/fail targets, a 90-day launch plan, 10 interview questions for developers and purchase teams, and 5 assumptions to test. Download the kit →
Thinking about building Lowclinker or something close to it? The make-or-break work is securing LC3 supply and getting buyers to accept a cement their specs don't yet name, and that's the kind of problem I help founders work through. If you need a hand, you know where to find me. Talk to Yash →
For illustration only. Names are fictional and ideas hypothetical; sourced facts are real but may be out of date. Nothing here is legal, financial or professional advice, and Yash Khatri is not personally liable for any use of it. Read the full disclaimer.