The phone of an RGE certified insulator never stops ringing now that MaPrimeRénov has classed lost loft insulation as a priority action. That's good news — until you realise that three out of ten calls concern non-eligible homes: flats in co-owned buildings without a general meeting vote, converted lofts already treated, recent buildings under the RT 2012 standard. Each pointless visit costs two to three hours of work. At a rate of five non-profitable visits per month, that's a day and a half lost — without invoicing a single euro.
The solution is not to refuse leads. It's to filter them before driving out, by phone, with five precise questions. And since 2025, an AI voice agent has been asking these questions in place of the tradesperson — 24/7, without exception, with a qualification rate higher than that of an overworked secretary at the end of the day.
The loft insulation boom in 2026
ADEME estimates the number of French homes with poorly insulated lofts at 3.2 million — that is, lost lofts with thermal resistance below R 3.7 m².K/W, or converted lofts whose under-rafter insulation predates the RT 2005 standards. These homes are priority targets for MaPrimeRénov, which finances the insulation action under the MaPrimeRénov Parcours par Geste scheme.
The regulatory context amplifies demand. Since 1 January 2025, homes rated DPE G are banned from rental. Landlords with a G-rated property have two options: sell or renovate. Loft insulation is often the first action carried out because its cost-to-thermal-gain ratio is one of the best on the market. Classes E and F follow with a progressive ban by 2028 and 2034. The DPE calendar therefore generates a structural wave of demand, not a cyclical one.
The internal and external thermal insulation market is estimated at 4.8 billion euros in France in 2026, according to data from the French Building Federation (FFB). Loft insulation alone accounts for around 30% of this volume, i.e. 1.4 billion euros of annual works. The tension between the supply of RGE certified tradespeople — whose certification takes 12 to 18 months to obtain — and growing demand creates a paradoxical situation: tradespeople receive more requests than they can handle, but waste 25 to 35% of their commercial time on non-convertible leads.
The specific problem for RGE insulators is that MaPrimeRénov's popularity has generated a sharp rise in "curious" leads — owners who heard about the grant on TV or social media, who want to know if they too are entitled to it, but whose home does not meet the conditions. Identifying these leads upstream, before driving out, has become a direct profitability issue.
The 5 questions that filter out 30% of non-eligible leads
Phone qualification of a loft insulation lead rests on five control points which, taken together, allow non-eligible files or files with low conversion probability to be eliminated before any visit. An AI voice agent asks these questions in a natural conversational order — not as an interrogation — and collects the answers to generate an automatic qualification sheet.
Question 1: type of home
Detached house or flat in a co-owned building? This is the first market split. A flat in a co-owned building generally does not have individual access to the loft — it is communal. Carrying out individual insulation is either impossible or subject to a vote at a general meeting (GM). The GM process takes 3 to 6 additional months and requires obtaining the agreement of the majority of co-owners. The case is technically feasible but commercially very complex: the probability of conversion to a project within 30 days is below 15%. The AI agent detects this from Q1 and steers the conversation towards a realistic timeline rather than an immediate quote.
Question 2: lost loft or converted loft?
Do you use your loft as living space or is it inaccessible? This question distinguishes two radically different services. Lost lofts — inaccessible, used only as a buffer space — are treated by blowing mineral wool or cellulose wadding in bulk. A 100 m² project takes 1 to 2 days. Converted lofts — transformed into a bedroom, office or playroom — require under-rafter insulation between the rafters, with vapour barrier and interior finish. The surface to be treated is 2.5 times greater than the floor area, the timeframe extends to 3-5 days and the budget is significantly higher. AI adjusts the script and the type of quote to prepare according to the answer.
Question 3: current DPE known?
Do you know the energy class of your home — A, B, C, D, E, F or G? The DPE conditions the level of MaPrimeRénov grant. Classes E, F and G are priority for MaPrimeRénov Parcours par Geste — the grant can reach 75% of the cost of the works for very low-income households. Classes C and D remain eligible but with lower grant ceilings. Classes A and B are virtually excluded from the scheme because their energy balance is already satisfactory. When the owner does not know their DPE, the AI agent informs them that a recent DPE (less than 10 years old) is available on the ADEME area or from the notary in case of recent sale.
Question 4: year of construction of the home
Was your house built before or after 2000? Buildings prior to 1975 (before the first thermal regulation) are ideal candidates — often poorly or not insulated. Buildings between 1975 and 2000 have partial insulation. Buildings after 2000 — under RT 2000, RT 2005 or RT 2012 standards — already have insulation conforming to their construction regulation. The thickness installed at the time often does not match current MaPrimeRénov criteria, but the probability of significant thermal gain is lower. The AI agent uses this criterion to calibrate the discourse on expected return on investment.
Question 5: occupant status
Are you an owner-occupier, landlord or tenant? Tenants cannot apply for MaPrimeRénov — the grant is reserved for owners. A tenant can flag the need for insulation to their landlord, but cannot commission the works. Owner-occupiers have access to MaPrimeRénov grants according to their reference taxable income. Landlords have had access to MaPrimeRénov since 2024, but with different ceilings. This distinction avoids sending a quote and mobilising a team for a tenant without decision-making power.
"Before, I systematically drove out as soon as someone called me about insulation. Out of ten visits, three or four led to a project — the rest were either a flat, or someone who just wanted an opinion. Since AI has been filtering calls, I drive out on nine qualified files out of ten."
— Sébastien M., RGE certified insulator, Auvergne-Rhône-Alpes region
Lost lofts vs converted lofts: two different trades
The lost loft / converted loft distinction is fundamental in the insulation market. It conditions the technique, the project time, the price and the level of grant. A tradesperson who does not detect it upstream may find themselves pricing an under-rafter file when the customer was expecting blown glass wool — and losing the sale on a misunderstanding.
Lost lofts: the fast and profitable project
Lost lofts are inaccessible or barely accessible — they are not converted into living space. Insulation is carried out by blowing bulk material onto the loft floor: glass wool, rock wool or cellulose wadding. An 80 to 120 m² project generally requires 1 to 2 days of intervention for a two-person team. The target thermal resistance is R ≥ 7 m².K/W to meet MaPrimeRénov criteria, which corresponds to approximately 28-30 cm thickness depending on the material.
The MaPrimeRénov grant for lost loft insulation can reach 75% of the amount of works for very low-income households (incomes below ANAH category 1 ceilings), with a ceiling of subsidisable works set by the order in force. The remaining balance can be supplemented by Energy Saving Certificates (CEE), combinable with MaPrimeRénov, and by the zero-rate eco-loan (éco-PTZ) for owners who wish to spread out the financing.
Converted lofts: the technical service
Converted lofts are transformed into habitable space — bedroom, office, bathroom, playroom. Insulation is no longer done on the floor but under the roof rafters, between the rafters or with counter-battens. The technique requires the installation of a rigid or semi-rigid insulator (rock wool in panel, polyurethane, polyisocyanurate), followed by a vapour barrier and an interior finish (plasterboard or wood).
The surface to be insulated is significantly greater than the floor area — generally 2.3 to 2.7 times greater depending on the roof slope. A converted space of 40 m² represents approximately 95 to 110 m² of under-rafter surface to treat. The project lasts 3 to 5 days and mobilises a more specialised team. The MaPrimeRénov grant applies under the same eligibility conditions, but the absolute amount of works — and therefore the grant — is significantly higher. The AI agent automatically detects the type via Q2 and notes the file type in the qualification sheet sent to the tradesperson.
Integrating MaPrimeRénov into the sales process
MaPrimeRénov is not just a sales argument — it is an administrative process with a precise chronology that the tradesperson must master to transform a lead into an invoiced project. Poorly positioned in the sales pitch, it becomes a hindrance. Well integrated, it accelerates the customer's decision.
The MaPrimeRénov insulation chronology
The standard process for an owner who starts a MaPrimeRénov request takes place in four stages. First, the online submission of the request on the maprimerenov.gouv.fr portal, with supporting documents (tax notice, DPE, quote from the RGE tradesperson). Then, the examination of the file by ANAH, which generally takes 2 to 4 weeks depending on the time of year — delays lengthen at the beginning of the calendar year when requests flood in. Then, after ANAH's approval, the start of the project — it is imperative to wait for approval before starting the works, on pain of losing the grant. Finally, after the paid invoice, payment of the grant directly to the tradesperson if the immediate advance mechanism is activated, or to the owner in case of full prior payment.
The "ANAH approval in hand" lead: absolute priority
A segment of leads deserves particular attention: owners who call specifying that they already have their ANAH approval in progress and are looking for an RGE tradesperson available quickly. These leads are ultra-hot. The decision time is short — the ANAH approval has a validity period and the customer wants to start without delay. The conversion window is 48 to 72 hours maximum: if the tradesperson does not call back within this time, the customer will go to a competitor.
The AI voice agent is configured to detect this situation during qualification — "do you already have a notification of approval from ANAH?" — and to trigger an immediate priority alert to the tradesperson, even outside opening hours. This type of lead must never land on voicemail or in an email inbox consulted the next morning.
The immediate advance: the conversion lever
Since 2021, the immediate advance scheme allows the tradesperson to receive the MaPrimeRénov amount directly, without the customer having to advance the sum. The customer only pays the remaining balance. This mechanism radically transforms the sales dynamic: the customer no longer has to manage cash advance and wait for reimbursement. The tradesperson mentions this point at the time of contact — the AI agent can integrate it into the qualification script to immediately remove the most frequent budget objection.
Results for RGE certified insulators with AI voice
On a panel of 11 RGE certified insulators having activated the AI voice agent between September 2025 and March 2026, the results in terms of qualification and profitability are consistent. The panel profile covers businesses of 1 to 8 employees, in urban and peri-urban zones, mainly specialised in lost lofts and under-rafters.
Reduction of non-profitable visits
Before activating the AI agent, the panel tradespeople carried out on average 40% non-profitable visits — drive-outs that did not lead to a signed project within 60 days. The main reasons: flat in a co-owned building (18% of cases), lofts already insulated or recently built (12%), tenant without decision-making power (7%), unsuitable budget despite eligibility (3%). After activating the voice agent and integrating the 5 qualification questions, this rate fell to 12% — a 70% reduction in non-profitable visits.
Time freed up and additional projects
The reduction in non-profitable visits freed up on average 58% of the time previously devoted to drive-outs with no follow-up. This time has been reinvested in effective project capacity. On the panel, this translates into an average of 2.3 additional projects per month per tradesperson — without hiring or extending hours. For solo tradespeople or small teams with saturated capacity, it is often the difference between refusing projects and accepting them.
"I no longer drive out for a flat in a co-owned building without a GM agreement — AI filters that directly. And when someone calls with their ANAH approval already validated, I receive an SMS alert immediately, even at the weekend. I signed three projects this quarter thanks solely to this alert."
— Nathalie R., manager of an RGE insulation company, Seine-et-Marne
A less expected benefit: the quality of the appointments themselves has improved. The tradesperson arrives with a pre-filled qualification sheet — type of loft, DPE, status, estimated surface, customer availability. The appointment starts directly on the technical solution and pricing, rather than on a re-collection of basic information. The first-visit signing rate has progressed from 34% to 51% on the panel.
Frequent questions from insulator tradespeople
Can a flat in a co-owned building benefit from MaPrimeRénov for insulation?
Yes, via the MaPrimeRénov co-ownership scheme (formerly MaPrimeRénov Copropriété). This scheme applies to insulation works in common areas decided at a general meeting, with a managing agent who centralises the request. The process is more complex and longer — count on 3 to 6 additional months compared to an individual request. For tradespeople, it is a different market that requires a managing agent contact and a collective proposal. The AI agent can detect this case and orient the lead towards a dedicated process rather than towards a simple individual quote.
Is loft insulation eligible for the CEE scheme on top of MaPrimeRénov?
Yes. Energy Saving Certificates (CEE) can be combined with MaPrimeRénov for loft insulation. The CEE issuer (energy supplier or distributor) pays a complementary bonus to the tradesperson or to the customer, according to the scales in force. This bonus is added to MaPrimeRénov and can further reduce the remaining balance. The AI agent can flag this opportunity during qualification to reinforce the sales argument and reduce the price barrier.
What minimum thickness is required to qualify for MaPrimeRénov insulation?
The minimum thermal resistance required for lost lofts is generally R ≥ 7 m².K/W according to the MaPrimeRénov scale order in force. In practice, this corresponds to about 28 cm of glass wool (λ = 0.040 W/m.K), 30 cm of blown cellulose wadding (λ = 0.040 W/m.K), or 26 cm of rock wool. For converted lofts (under-rafters), thickness criteria vary according to the type of system and insulator. The RGE tradesperson must certify the thermal resistance achieved in the end-of-works certificate to unlock the grant.
Does the tradesperson receive MaPrimeRénov directly or the customer?
Since 2021, the tradesperson can opt for the MaPrimeRénov immediate advance mechanism. In this case, the grant is paid directly to the tradesperson after completion of the works and transmission of the invoice. The customer only pays the remaining balance from the start. This scheme is optional — the tradesperson must request it and register for the mechanism on the dedicated portal. It considerably simplifies sales conversion by eliminating the argument "I don't have the funds to advance".