A passive, energy-positive house.From plans to reality.
Very little heating, solar energy and decisions designed together. A completed project showing how I turn an unfamiliar domain into something real.
With no building background, I learned Revit, redesigned the house and led around twenty work packages. My contribution: design, coordination and construction, alongside the contractors’ expertise.
Personal projects and volunteer contributions, with no commercial activity.
The useful question: how does it all work together?
“Passive” means greatly reducing heating demand. “Energy-positive” means aiming to produce more energy than the building needs in its annual balance. Here, the regulatory calculation concludes a positive balance; measurements and their scope are explained below.
The goal is more than collecting equipment. A window should admit useful winter sunlight without turning the room into a greenhouse in summer. The plans help resolve these conflicting needs before construction.
What this demonstrates: thinking in systems, comparing options and anticipating their effects in use.
Low winter sunlight enters through the windows. Insulation and triple glazing help keep that warmth inside.
The sun is higher: the roof overhang provides shade. External blinds and night-time ventilation complete the approach.
Gold traces show sunlight and its warmth spreading indoors.
Rays stop at the overhang. The blue flow illustrates heat removal by ventilation when the night air is cooler.
Produce energy with sunlight
Panels for electricity and separate collectors for hot water. Two different uses of the same resource.
Keep warmth inside
Extra insulation, triple glazing and a carefully built envelope: reduce demand before choosing a heater.
Plan for hot days
Shade, external blinds, earth inside a wall and night-time ventilation. Summer comfort starts with the plans.
Use water differently
Rainwater collection and plant-based wastewater treatment: include simple solutions in the project too.
- Insulate
- Keep air inside
- Keep cables separate
An invisible detail. A measurable result.
Behind the finishes, a membrane limits air leakage. If every cable and socket punctures it, good insulation alone is not enough. The solution: give services their own space on the room side to preserve that layer.
This construction method comes from EcoBois14, the company that fabricated and erected the timber frame. I did not invent it. My contribution was designing electrical and plumbing systems around it, coordinating the work and installing the finishing boards.
In the independent test, compared with the passive-house limit. The result reflects careful connections and workmanship.
- This house: 0.20
- Passive-house limit: 0.60
Same test at 50 Pa; air changes per hour. This measures airtightness, rather than total heating consumption.
What this demonstrates: preserving a requirement across several trades, right through to checking the result.
A technical house. With earth inside a wall.
The first design included roof glazing. A professional warned me about overheating; the thermal calculation confirmed the risk. I changed the design instead of discovering the problem after moving in.
A roof overhang and four external solar blinds provide shade. Earth inside an internal wall adds mass to soften temperature swings. Roof insulation and opening windows at night complete the approach.
The earth came from the site. It is a simple solution within a project that also includes solar panels and a KNX home-automation installation that I designed and wired.
What this demonstrates: listening to a warning, checking an idea against calculations and combining technology with simple solutions.
From needs to plans. From plans to construction.
The result is a house. The skills are project skills: learn, specify, coordinate, build and check.
- 2015
Define the needs
Comfort, low heating demand and solar production. A specification before choosing equipment.
- 2016
Take over the design
Learn Revit, redesign the house and submit a new permit in seven weeks. Approval received on 25 May.
- 2016–2017
Coordinate the trades
Around twenty work packages managed directly. Design electrical and plumbing systems and coordinate the work.
- 2017–2019
Test, then observe
Independent airtightness test, energy study and readings after moving in. Compare the completed work with the intentions.
What I took responsibility for
- The specification, Revit model and new permit application.
- Selecting and coordinating around twenty work packages.
- Electrical design, modelled plumbing, KNX automation and part of the interior construction.
What professionals contributed
- The construction method, fabrication and erection of the timber frame.
- Specialist work and help during construction.
- Thermal studies and an independent airtightness test.
What worked less well: the schedule
I scheduled the interior work as if I already worked at a professional’s speed. Moving in happened thirteen months later than planned. The lesson: budget time for learning and coordination as well as doing the work.
Results that can be explained and checked.
A number is useful when its meaning is clear. Here, the independent test, regulatory calculation and electricity readings answer different questions.
- Air leakage is controlled
- Airtightness measured at 0.20, against a passive-house limit of 0.60. The timber-frame company commissioned the test, performed by EDM Énergie in June 2017.
- Supplementary heating is low
- 226 kWh recorded over a year on the ventilation-heater submeter. Heated towel rails are excluded: this is not the consumption of all heating.
- The calculated energy balance is positive
- The September 2018 regulatory study concludes that production exceeds demand within its calculation scope. The house is not presented as Passivhaus-certified.
Measurements, sources and limitations
- Airtightness: n50 = 0.20 air changes per hour at 50 Pa. EDM Énergie certificate dated 20 June 2017. French Q4 indicator = 0.05 m³/(h·m²).
- Regulatory balance: Cep = −12.3 kWh of primary energy per m² per year, against a limit of 50.2. Study dated 6 September 2018. A calculated result under that study’s conventions.
- Meters photographed in April 2019: 6,168 kWh exported and 3,842 kWh imported. These are cumulative meter readings; alone they do not describe total household consumption or a complete annual balance.
- Heating: submeter dedicated to the ventilation’s supplementary heater, excluding heated towel rails. Occupancy and weather affect the result.
Construction documents are private. Their titles, dates and values are cited here to identify where the results come from.
Check the airtightness limit with the Passive House Institute ↗Equipment and technical decisions
| Decision | What it does | Documented specification |
|---|---|---|
| Wall insulation | Limit heat loss | 29.5 cm of cellulose insulation |
| Roof insulation | Limit heat transfer through the roof | 44 cm in the technical specification |
| Triple glazing | Admit light while limiting heat loss | Uw 0,78 W/(m²·K) |
| Heat-recovery ventilation | Renew indoor air while recovering heat from outgoing air | Specified efficiency 93.3% |
| Photovoltaics | Generate electricity | 34 modules, 5,780 Wp |
| Solar thermal | Heat water with sunlight | 5.4 m² of collectors |
| Digital model and home automation | Coordinate plans and design automation | Revit · KNX ETS5 |
Sources: permit dossier, timber-frame technical note dated 12 June 2017, thermal study dated 6 September 2018 and Consuel certificates from September 2017 and February 2018.
Understand a need. Follow through to implementation.
The house shows my ability to learn and coordinate a physical project. Foncier shows the same approach applied to a digital tool: bring scattered information together and make it usable.