Blog/Argile and installers: from diagnosis to sizing
Argile product

April 26, 2026

5 min read

Argile: diagnosis and sizing for installers

On site, an accurate diagnosis and correct sizing are what save you from callbacks, repeated adjustments and runaway energy bills. Taking the time to ask the right questions, floor area, insulation, usage patterns, emitters, secures your equipment choice and your commissioning. The result: an installation that keeps its promises, and a reputation that follows.

Why diagnosis has become essential for RGE installers in 2026

Quickly spotting a home's weak points (insulation, ventilation, heating) before quoting

A good diagnosis shines a light on the losses: walls, loft, air leaks, insufficient ventilation, an ageing generator. For the installer, it's the simplest way to quote on clear grounds and avoid a rough guess at a price. With a few reliable data points, you prioritise the work and set the budget from the very first visit, with no surprises.

Securing eligibility for aid (MaPrimeRénov', CEE) with consistent data

In 2026, files are checked more closely. Floor area, usage, envelope characteristics, ventilation, and the declared output and efficiency all need to tell the same story. A consistent diagnosis makes it easier to put together the evidence expected for MaPrimeRénov' and CEE, and cuts down on back-and-forth, in the right format. If you want to avoid rejections, also see our article on avoiding MaPrimeRénov' file rejections.

Avoiding specification errors: oversizing, undersizing, discomfort

Without a diagnosis, you risk an oversized heat pump, or the opposite, leading to short cycling, noise, higher bills and discomfort. By cross-checking actual needs, emitters and ventilation, you size correctly, protect your RGE liability, and deliver a stable result, summer and winter alike.

Carrying out a reliable energy diagnosis in a few minutes with Argile

Fast energy diagnosis: assessing the existing building and comparing several renovation scenarios

With Argile, you describe the existing building and get an initial diagnosis in a few minutes. Handy for an installer who wants to scope a project before quoting. You compare several scenarios. For example, insulation alone, insulation plus ventilation, or a heating system replaced with a heat pump. You quickly see what actually moves the needle on performance.

Feasibility analysis: identifying technical constraints at the address (Open Data, installation limits, access)

The platform cross-references public data on the building and its local context to spot potential blockers. Site access, constrained zones, dwelling type, feasibility of installation. You build the right instincts from the outset, and avoid quotes that go off the rails at the first unforeseen issue.

Preparing the technical visit: checklist, photos, measurements and things not to forget on site

Argile helps you prepare a tight, well-organised visit with a simple template. The goal: leave with the right information, with no second trip. To go further, also see on-site diagnosis.

  • Photos of equipment, supply and drain lines, access to the loft or technical room
  • Useful measurements: floor area, heights, visible thicknesses, pipe/duct run lengths
  • Client information: usage patterns, comfort, cold rooms, occupancy constraints

Sizing: methods that help the installer get it right

Choosing the right output and the right emitter: what to check before sizing

Before talking about kW, the installer starts with a room-by-room heat loss calculation. They also check the existing emitters, radiators or underfloor heating, and the target flow temperature. An oversized heat pump will short-cycle, an undersized one will push the backup heater.

Accounting for actual usage: occupancy, domestic hot water, controls, client habits

Sizing isn't decided solely at -7°C outside. Occupancy, setpoints, absences, and domestic hot water (DHW) production all change things. Look at the controls, the scheduling and the heating curve. This is often where comfort is won, without overconsuming.

Prioritising the work: when insulation and ventilation change the sizing

If loft insulation or external wall insulation is planned, size for the post-work scenario, or formalise a staged approach. Better-tuned ventilation stabilises humidity and reduces peaks. An energy audit or a thermal study avoids sizing "in the dark".

From diagnosis to quote: pricing, aid and the client's decision

Generating a clear preliminary quote: work items, options and sizing variants

From the diagnosis, build a line-by-line preliminary quote. Separate out insulation, ventilation, heating, and controls, and add materials, labour and points requiring attention. Offer 2 sizing variants (e.g. an 8 kW or 10 kW heat pump, insulation thickness) with your assumptions. The client sees what changes and why.

Including aid in the quote: MaPrimeRénov' and CEE estimates to limit back-and-forth

In the quote, show a MaPrimeRénov' and CEE estimate for each work item, then the remaining cost to the client. Specify the key conditions (RGE, dwelling, income, applicable CEE technical sheet) and note that 2026 amounts are indicative until validated. For an installer, this means less back-and-forth and a faster decision. To scope this part, you can rely on a practical guide to CEE and MaPrimeRénov' aid.

Presenting understandable scenarios: energy savings, comfort and budget (without jargon)

Present 2 to 3 scenarios, easy to read at a glance. For each, state the expected energy savings (kWh and euros), the winter-summer comfort improvement, and the total budget. One sentence is enough to sum up the logic, followed by a before/after comparison. The client chooses without getting lost in the technical detail.

Rolling out a simple method for your installer team (field + office)

Standardising your process: information gathering, technical validation, RGE traceability

Give every installer the same visit template. Dated photos, measurements, equipment labels, pipe/duct mapping. Back at the office, a short technical validation: consistency of output, emitters, ventilation, electrical protection. Keep clean RGE traceability: signed quotes, proof of qualification, product data sheets, visit reports.

Reducing the time between first contact and quote: key steps and checkpoints

A fast quote isn't about rushing at random. It's about chaining the steps without a break: remote pre-analysis, visit slot, pricing, review, sending. Add two checks: aid eligibility, technical compatibility (dimensions, access, condensate drainage). You avoid back-and-forth and surprises.

Saving time on admin: files, supporting documents and project tracking with Argile

Centralise the documents from the outset: ID, tax notice, quote, bank details, certificates. For CEE, plan ahead for the sworn statement and the compliant invoice. With Argile, you gather the field data, generate a preliminary quote and a full quote with aid calculated. Project tracking stays clear, from first contact through to the end of the job.

Key figures

to the nearest m²

PV sizing

+90% vs. rule of thumb

Accuracy gain

to the nearest watt

Heat pump sizing

Frequently asked questions

Plan for consistent, traceable data: heated floor area, description of the envelope (walls/loft/floors), existing ventilation, current generator (output, energy source, age) and dated photos of equipment/nameplates. Attach a sizing note (estimated heat demand, base temperature, emitters) and keep your site survey records: this greatly reduces requests for additional documents during inspections.

Pierre-Louis Guhur

CEO of Argile

Further reading

Argile productJuly 9, 2026
Case Study: A Complete Renovation of a 1970s House

A 1970s house is often a job that hides surprises, but also real potential for quick wins. You have to work around period insulation, ventilation that's sometimes absent, and equipment nearing the end of its life, all while keeping a workable schedule and budget. Here, we start from the concrete details to help you secure your choices and move forward without guesswork.

5 min read

Argile productJuly 5, 2026
Renovation scenarios: how Argile simulates the results

When a client is torn between several works options, you're the one who has to decide quickly, with concrete facts. By simulating several scenarios, you compare expected gains, budget and site priorities at a glance, without drowning in spreadsheets. That secures your quote and lets you move forward with a clear roadmap.

5 min read

Argile productJuly 4, 2026
The 90 types of renovation work catalogued by Argile

On an energy-renovation job, the difference often comes down to detail. As a tradesperson, you save time when the work items are clearly classified, with the right prerequisites and the right order of execution, from insulation through to final adjustments. Here's a simple method for quickly spotting the right levers, securing the quote, and moving forward without grey areas.

5 min read

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