Passive House / Performance
Comfort, from
the first sketch.
Performance is considered alongside the quality of space. The project brings together the site, the envelope and everyday use.
01 / The building as a whole
Comfort starts with the envelope.
Five principles, considered together from the first sketch. Explore their place in a simple building section.
01Continuous insulation
A thermal layer around conditioned spaces limits heat transfer.
02High-performance windows
Glazing, frames and installation work together. External shading helps control summer solar gains.
03Airtightness
Carefully detailed joints limit uncontrolled airflow through the envelope.
04Reduced thermal bridges
Thermal continuity also matters at corners and wall-to-floor junctions.
05Heat recovery ventilation
Controlled ventilation renews indoor air while recovering part of the outgoing air’s heat.
Principles: Passive House Institute · PHI — how a Passive House works
Inside the system
Fresh air. Recovered heat.
In a plate heat exchanger, incoming and extracted air travel through separate channels. Heat passes through the exchanger surface, prewarming the incoming air in winter.
The drawing shows heat transfer between the streams, not the recirculation of extracted air. System sizing, filtration and maintenance are part of the design and operation.
Passipedia — ventilation principles ↗Original diagrams by Zorlescu Architecture. Explanations informed by educational resources from the Passive House Institute and Passipedia.
02 / Evidence
An objective. A calculation. A result.
The design objective
What the team intends to achieve. It guides the work and still needs to be demonstrated.
The calculation or test
Evidence associated with a method, a stage and specific conditions. It must be read in that context.
Building certification
A separate assessment against the applicable criteria. A designer’s qualification does not certify a building.
03 / From the practice
M22: between house and garden.
The photographs follow the relationship between the house, its openings and the garden. M22 is not presented as a certified Passive House.
See the M22 photographsAlexandru Zorlescu is a certified Passive House designer.
About the architect
Services and investigation
Understand. Measure. Refine.
New buildings and renovation
We develop architectural projects with energy performance objectives for both new buildings and existing homes. The envelope, thermal bridges, airtightness and building services are considered together with comfort and the quality of space.
Energy modelling · designPH and PHPP
designPH supports three-dimensional modelling and preliminary energy evaluation. Its data can be exported to PHPP for further calculation. The quality of the assessment depends on the input data, the method and the verification of the model.
Thermal imaging
Thermography helps locate surface temperature differences and investigate possible discontinuities in the envelope. Results are interpreted in relation to weather, temperature difference, surface properties and the inspection conditions. A thermogram alone does not establish the cause of an anomaly.
Temperature, humidity and material moisture
Measurements help document the conditions in a space and the behaviour of materials. Evaluating thermal transmittance requires suitable sensors and a defined method; a general temperature and humidity reading is insufficient.
Airtightness testing · Blower Door
A pressure test evaluates air leakage through the building envelope. The report identifies the method, building volume, test conditions and results. Testing can inform work during construction and the final performance assessment.
CO₂ monitoring and operation
Monitoring CO₂ concentration, temperature and humidity can help assess ventilation and patterns of use. Readings are interpreted with the occupancy, sensor location and measurement period in mind.
A defined scope of assessment
Energy analysis for design is distinct from a regulated energy audit or an energy performance certificate. Where those documents are required, the relevant authorised specialist is involved. Building certification is also a separate assessment.
The scope, sequence and deliverables are defined for each project. References reviewed on 9 September 2026: PHI — Planning tools · Passipedia — Blower Door · Legea 372/2005