Louis Airy

Renovating an old building tied to local history is a project where every choice matters. You need to gain comfort and energy efficiency without betraying the character of the place, or getting bogged down in unnecessary details. With a clear method and the right materials, you move fast, cleanly, and secure the result.

5 min read

On an external wall insulation job site, water doesn't forgive mistakes. A poorly connected flashing, a forgotten window sill, and runoff ends up staining the façade or weakening vulnerable points. With the right sealing details from the prep stage, you secure durability and avoid callbacks that blow up the schedule.

6 min read

When you're handling a renovation, comfort can hinge on invisible details. An air leakage test gives you a clear measurement of air leaks, useful for deciding where to redo seals, penetrations and windows, instead of working blind. The payoff: fewer callbacks, and performance that holds up over time.

5 min read

An agricultural building conversion is settled by two texts before it is settled on site: article L. 151-11 of the French planning code, which governs change of use in agricultural and natural zones, and the decree of 30 May 2016, which triggers insulation duties as soon as space is converted to habitable use. Here are the binding thresholds, the thermal resistances to hit, and what the survey has to record before any pricing.

5 min read

The refrigerant charge commands two things: how the machine performs and what you owe the regulator. The second is not read in kilos but in tonnes of CO2 equivalent, and the conversion is one multiplication by the GWP. Here is the conversion table by refrigerant, the leak check interval table, and what gets logged after every job.

5 min read

When your clients want to cut their bill without adding a complicated system, capturing the sun with a well-designed wall can make the difference. This simple principle turns an exposed wall into a heat reservoir that slowly releases warmth into the home, especially in mid-season. With the right design and installation habits, you gain a concrete, low-tech, durable selling point on your jobs.

5 min read

When a client is still hesitant about renovating, keep it simple. A better-insulated, better-heated home means lower bills and a property that sells faster, often at a better price. For you, the tradesperson, that's a clear argument to put in the quote. You're not just selling works. You're securing the property's value, from the first viewing right through to resale.

5 min read

On a refrigerant connection, poorly prepared brazing can wreck the tightness of the joint, and you often only find out too late, at commissioning. With a few simple steps — protection against oxidation, clean tubing, controlled heating — you secure your joints and save time on site. The idea is clean, durable work, and a client who doesn't have to call you back over a leak.

5 min read

When a home stays too cold, the occupants soon pay the price. Discomfort, moisture that sets in, greater risk for the most vulnerable, and ultimately habits that push the bill up to compensate. As a tradesperson, you can make a simple diagnosis and guide clients toward the right habits and the right work, without shifting the problem elsewhere.

5 min read

Air leakage through an envelope is diffuse, and no public source says how much each individual weak point contributes. What is measured, on the other hand, are the thresholds to hold, the equivalent leakage area of an ordinary dwelling and the share of heating that escapes through infiltration. Those three figures are what justify the time spent treating weak points.

5 min read

With hot water production, a breakdown never happens at a good time. With a simple inspection routine, you secure performance, avoid overheating, and extend the life of the tank, circulators, and collectors. As a tradesperson, a few checks well spaced out over the year often make the difference between a reliable system and repeat warranty callbacks.

5 min read

A solar water heater is not sized from the number of occupants: schemes ask for a declared tapping profile among M, L, XL and XXL, defined by Regulation (EU) 814/2013 and tied to a specific reference energy. Here is that table, the 2 m² collector floor, and how to check that the collector and volume pairing holds thermally before you price the job.

5 min read

When a heat pump breaks down mid-project, it's not just a technical hiccup. It's lost time, a worried client, and sometimes a bill that lands on the wrong side of the ledger. To avoid unpleasant surprises, you need to know precisely what's covered, for how long, and what can be refused depending on maintenance, installation, or the parts involved.

5 min read

On an external wall insulation job, the render is your signature. Machine-sprayed or hand-applied, the right choice affects pace, finish consistency and touch-ups, without tripping you up on the details. If you need to keep to schedule while delivering a clean, durable facade, it's best to set your criteria upfront. Let's walk through the concrete points that make the difference, depending on your team, your substrates and your job-site habits.

4 min read

When a project moves fast, every detail matters to hit your deadlines without sacrificing performance. A wall that goes up simply, with built-in insulation, can save you steps, limit thermal bridges and reduce the points to watch during installation. Here we give you concrete benchmarks to choose the right solution, assemble it cleanly, and avoid the mistakes that cost dearly at the airtightness test.

5 min read

An unbalanced manifold means one collector working flat out while another idles, and an installation that will never reach the yield it was sold on. Branch symmetry, balancing with flow meters and hunting down high points are all decided at installation. On the paperwork, the collectors have to carry a Solar Keymark certificate and the installation an MCS certificate, or the funding route closes.

5 min read

On a job site, the difference sometimes comes down to a few decimal places. Concrete, brick and concrete block don't have the same thermal conductivity, and that changes everything about insulation thickness, thermal bridge treatment and budget. As a tradesperson, you save time when you know what to expect from a wall before you even talk about wool, panels or render. Here we lay out the orders of magnitude simply, so you can decide quickly and accurately.

5 min read

Before starting a renovation, your clients want concrete answers, not bad surprises mid-project. A poorly vented wastewater system, a saturated septic tank or a badly placed outlet, and the schedule derails, with costly rework. By checking a few simple points during the initial site visit, you secure the project and keep control of quality.

5 min read

Reusing an existing duct rather than running new ductwork is often the only workable option in renovation. It still pays to know what the energy calculation makes of it, because three solutions built on the same duct are scored very differently: from 1.17 to 2.24 m³/(h.m²) of conventional flow, a factor of two between best and worst.

6 min read

A hybrid gas heat pump only qualifies if two conditions hold at the same time: the seasonal space heating efficiency calculated with the backup, and a heat pump coverage rate excluding the backup of at least 70 %. The second is the one that gets lost in commissioning, because a bivalence point pushed too high to avoid defrost cycles sends the system onto gas and takes the installation outside its own eligibility criterion.

4 min read

Between bills that keep shifting and clients who want more autonomy, you’re often looking for a simple way to make the most of every kWh produced, without adding a technical room or a physical battery. The virtual battery answers exactly that need: it “sets aside” the energy fed into the grid so you can recover it later, with rules and costs that need to be clearly framed from the quote onward. In the lines that follow, we help you clearly explain the principle, the points to watch, and the right field practices to secure your job and keep your clients satisfied.

5 min read

Between logs, pellets and wood chips, the right choice comes down to the practical details. You save time on site when the fuel matches the feed rhythm, the storage space and the level of automation expected. With the right criteria, you secure your client's comfort and your own settings, without oversizing or complicating the installation.

5 min read

When a client asks you "does it use a lot of power?", you need a simple benchmark to compare units and justify your choice. SEER gives you that performance level over a season, not just a single lab measurement, and that changes everything for sizing, explaining and quoting. Master this indicator and you save time on quotes while avoiding nasty surprises once the equipment is installed.

6 min read

When a heat pump operates with too low a flow rate, trouble arrives fast: noise, short cycles, faults and service callbacks. As a tradesperson, you can secure the installation right from commissioning with a simple setup that stabilises circulation, even when thermostatic valve heads close. The result: a calmer heat pump, and a job that runs smoothly.

5 min read

Your clients don't just want equipment, they want comfort that holds up over time, with no bad surprises. By shifting from selling a product to selling a service, you can smooth out costs, secure performance and build recurring revenue, while staying concrete about installation quality and follow-up. It's another way to showcase your expertise, and often, to sell more simply.

5 min read

In commercial buildings, a heavily glazed façade is often where everything is decided: summer comfort, draughts, and bills that climb without warning. In renovation, you can correct the weak points without halting operations on site, by securing airtightness, thermal bridges and the right level of insulation. With a simple approach and well-executed details, you turn a "handsome façade" into performance you can measure.

5 min read

Your clients want heating that stands out, without cutting corners on comfort or consumption. It's up to you to find the right balance between look, power and placement, to avoid "nice but lukewarm" or high-performing but impossible to install. With a few simple benchmarks, you can propose a solution that enhances the room and your project.

5 min read

When the budget is tight, every quote counts, and it's often you, the tradesperson, who makes the difference between a renovation that's merely endured and one that delivers real comfort. By asking the right questions, prioritising the work that matters, and guiding the household step by step towards funding and good practices, you secure both the job site and the client's trust. The result is fewer hesitations, faster decisions, and renovations that deliver on their promises in the field.

5 min read

In a low-energy or new-build home, a wood stove runs into its minimum output long before it runs into its efficiency: a high-performance envelope calls for 2.5 to 3.5 kW over 100 m² when the smallest log stove on the market delivers 4 to 5 kW at rated output. A room-sealed appliance solves the second problem, the combustion air a tight dwelling no longer supplies through its own defects.

5 min read

Between incoming calls, quotes that need following up, and job sites to keep on track, prospecting is often the last thing on the list. Yet when the pipeline dries up, the whole organisation takes a hit. The idea here is to give you a simple method, from first contact through to installation, to secure a steady flow of qualified leads.

5 min read