Best carbon accounting software for construction in 2027

In short

• A contractor's deadline is a tender date, which rules out any tool that needs a long implementation.
• The company footprint and the building footprint are separate exercises. Only one of them is software you subscribe to.
• Two of the seven published a paid price on 27 August 2026. One more publishes a free tier and no figure above it.

For a contractor the honest shortlist is Hedgehog, EcoHedge, Coolset, Greenly, Watershed, Persefoni and Seedling, and the thing that separates them is not features but what they will show you before you sign. On 27 August 2026 two of the seven published a paid price, a third published a free product without pricing what sits above it, and the other four were quote only. Two of the seven publicly named a tender output we could verify. Which one you want depends on whether you are chasing a Dutch award advantage, a UK public works threshold, or a corporate ESG report that happens to include a construction division.

We build one of these. It is described here on the same terms as the rest, and the paragraph explaining when to buy something else is written in earnest.

Why does the buying decision look different in construction?

Because the deadline is a tender date rather than a reporting year, and because the emissions are almost entirely in what you purchase.

Scope 3 dominates a contractor's footprint, mostly through purchased materials, and concrete and steel usually lead. Your fleet and your site energy are real and they are countable, but they are not where the mass is. Meanwhile the data that would answer the question already exists in your purchase ledger, split by material, alongside subcontractor invoices and plant and equipment fuel.

The person buying is usually a KAM coordinator or a bid manager working to a submission date. That changes the specification more than any feature comparison does. A platform that needs a three month implementation is not a candidate, whatever it can do in month four.

Which rules are actually driving the purchase?

Three, and they pull in different directions.

The CO2-Prestatieladder. In the Netherlands it delivers an award advantage in public tenders. Rijkswaterstaat awards on it and ProRail has done so since December 2010. Rijkswaterstaat moved to Handboek 4.0 on 1 July 2026, so that switch is already behind you. ProRail intends to use 4.0 for newly published tenders from 1 January 2027, which is the date still ahead. This is a certification with an external audit, so what you need from software is a repeatable inventory and evidence that survives a certifying body, not a dashboard.

MPG and BPM 2.0. In force from 1 July 2026 and aligned to EN 15804+A2, covering impact categories 11 to 19. Offices face a 15 percent tighter requirement and utility buildings get an MPG requirement for the first time. This is a building-level calculation, not a company-level one, which matters enormously for what you should buy. We unpack the change in what BPM 2.0 does to the MPG score.

PPN 006. For UK public works above GBP 5 million a year, a published Carbon Reduction Plan is a pass or fail gate. The plan format is prescribed and the refresh cycle is annual. The detail is in the PPN 006 checklist.

A contractor working across the Dutch and UK public markets faces all three. Nothing in this category covers all three out of the box, so the realistic question is which one is costing you tenders now.

Where do the two calculations diverge?

This is the distinction that decides whether a subscription is the right purchase at all.

Contractors who buy an organisational platform expecting it to produce an MPG figure discover the mismatch late. At Hedgehog the platform does organisational footprints and product-level work including LCA, EPD, ECI (MKI in Dutch) and product carbon footprints is delivered as a service. Whichever vendor you pick, ask this question in the first call rather than the fourth.

What separates the seven on evidence you can verify?

We read each vendor's public pricing page and G2 profile on 27 August 2026.

Read the last column carefully. "Not verified in our check" means we did not find the claim on the pages we read on that date, not that the capability is absent. Vendors publish unevenly and any of them may support a Dutch or UK tender output without saying so on a page we happened to open. Ask them directly.

Two notes on the price column, because it is the one we are most likely to get wrong in our own favour. Persefoni publishes a free product: its pricing page offers Persefoni Pro free and names GHG Metrics Reports as a paid add-on, without pricing the add-on. Seedling publishes a Start for Free link but no plan, limit or figure behind it, so we are not calling that a free tier until someone confirms what it gives you.

The EcoHedge row comes from their own published comparison material, read on 27 August 2026, which also states native one-click integration with Xero, QuickBooks and Sage and a library of 277,000+ emission factors. Their factor count is larger than ours and we say so plainly.

What should a contractor test in a demo?

Six things, and every one can be tested inside an hour with real data.

Load one month of the purchase ledger, unedited. Construction ledgers are messy, with merchant accounts, plant hire and subcontract labour all mixed together. Clean sample data proves nothing.

Split one project from the company total. Bid teams get asked for project-level figures constantly. Find out whether that means a new entity, a tag, or a manual workaround.

Ask what happens when the emission factor library updates. A certified ladder submission that silently changes underneath you is a problem at the next external audit.

Check the roles. A KAM coordinator entering, a director approving, and a certifying auditor reading, as three separate accounts.

Export to a spreadsheet, not a PDF. Every certifying body and every bid pack wants the working.

Ask for the year two price. This is an annual obligation with an annual audit, so a first-year discount that resets changes the real cost materially.

Which tool suits which contractor?

A Dutch contractor chasing a ladder tier. You want a repeatable organisational inventory, a Dutch-language product for the people entering data, and an export a certifying body will accept. Hedgehog names the CO2-Prestatieladder as a reporting output and supports English, French and Dutch. The wider practical case for the ladder is in the CO2-Prestatieladder for SMEs.

A UK contractor above the PPN 006 threshold. Both tools with published pricing name PPN 006. EcoHedge adds accounting integrations we do not have today, which is a genuine advantage if your data lives in Sage or Xero.

A mid-market European group with a full ESG reporting obligation. You are buying a reporting suite. Coolset is aimed at European mid-market companies, with 14 of its 18 G2 reviews from Mid-Market.

A large contractor with a global footprint and an investor audience. Watershed and Persefoni belong in that conversation. Expect a quote and a services component.

A contractor whose actual deliverable is an MPG figure. That is a modelling project. Buy it as one.

If your situation is none of these, the general filter in choosing carbon accounting software will narrow it faster than a feature grid.

Where is Hedgehog the wrong choice?

Three places, said plainly.

When you need a broad ESG platform. A Mid-Market customer rated us 3.5 out of 5 on G2 in June 2026 and said the platform is less complete for broader ESG data and reporting, with no data source management feature and no decarbonisation target monitoring. For a group building a full sustainability statement, that is the right criticism to act on.

When you expect the ledger to import itself. A Small Business reviewer wrote on G2 in August 2026 that it takes a lot of manual labour to load data, and that once the data is there it works perfectly, but getting it loaded is the challenging part. On a construction ledger that is a real week of work, and any vendor who tells you otherwise has not seen your data.

When the deliverable is per building or per product. Organisational platform, product service. Buy them separately and in that order only if the tender says so.

What should you do first?

Find out which single tender requirement is costing you work right now. Ladder tier, PPN 006 plan, or a client questionnaire. Buy for that one and ignore the rest until it is done.

Then load one month of the purchase ledger and see what happens. That hour tells you more about a vendor than a demo, and it tells you how big your own data problem is, which is the number the bid team actually needs.

You can do that on a free account with no sales call, or bring the tender document to a conversation first.

Sources: vendor pricing pages and G2 profiles for Hedgehog, EcoHedge, Coolset, Greenly, Watershed, Persefoni and Seedling, each read on 27 August 2026. EcoHedge comparison material read on 27 August 2026. Hedgehog platform, Hedgehog on G2. The ladder dates come from Rijkswaterstaat's announcement of its move to Handboek 4.0 and SKAO's announcement of ProRail's move on 1 January 2027, read on 28 August 2026. Re-check any vendor figure before relying on it. Verified 16 September 2026.

Facts on this page were last verified on 2026-09-16.