What is a passive house: a home designed to maintain thermal comfort throughout the year with very low energy consumption, minimizing the need for conventional heating or air conditioning. This is achieved mainly through a well-insulated envelope, airtightness, high-performance windows, and mechanical ventilation with heat recovery, as well as a design that takes advantage of the sun and limits losses.
What distinguishes a passive house from a conventional house
In a conventional home, comfort usually depends on "correcting" the interior with climate control (heating and air conditioning). In a passive house, the approach is reversed: first, energy demand is reduced as much as possible through design and construction, and then the little that remains is covered with highly efficient systems.
Elements that make the difference:
Highly insulated thermal envelope (facades, roof, and floors).
Minimized thermal bridges (points where heat "escapes" or cold enters).
High-performance carpentry and glazing (usually triple glazing, depending on the project).
Airtightness (control of unwanted air infiltration).
Controlled mechanical ventilation with heat recovery.
Compact design and solar orientation to take advantage of gains in winter and provide protection in summer.
Five key elements of a passive house
Thermal insulation
Insulation is not just about "more thickness": it must be continuous and well resolved at joints (floors, jambs, crowns, etc.). If there are discontinuities, demand increases and cold spots appear.
Avoid thermal bridges
Thermal bridges tend to concentrate in material changes, structures that pass through insulation, and where facades meet slabs. Reducing them prevents losses, condensation, and comfort issues.
High-performance doors and windows
Windows are a critical point: their quality and installation (seals, tapes, subframes, insulation continuity) determine much of the actual performance.
Airtightness or watertightness
It is not about "sealing" the house, but rather controlling where air enters and exits. Airtightness prevents drafts, energy loss, and condensation on walls.
Controlled mechanical ventilation with heat recovery
It constantly renews the air and filters particles, while recovering some of the energy from the extracted air. This helps maintain comfort and indoor air quality without significant losses.
Passive architecture allows for a reduction in a home's energy consumption through appropriate design, orientation, and materials.
Origin of the Passivhaus standard
The Passivhaus standard was developed in 1991 by Wolfgang Feist and Bo Adamson to define technical criteria for homes with very low energy demand. Among the best-known requirements are target values for heating demand, airtightness, and primary energy, as well as a design that reduces thermal bridges.
Note: The exact thresholds of the standard are handled as technical criteria of the certification system and must be verified in the project according to climate and type.
How a passive house works
Comfort is achieved through thermal balance:
In winter, the house retains interior heat (people, cooking, appliances) and takes advantage of solar gains when the design allows it.
Ventilation with heat recovery reduces losses when renewing the air.
In summer, the design seeks to prevent overheating: sun protection, orientation, heat gain control, insulation, and planned ventilation.
The key is for the building to work "in favor" of comfort, rather than relying on equipment to compensate for an inefficient envelope.
Advantages of living in a passive house
Energy savings
By reducing demand, consumption drops significantly compared to a conventional home. Actual savings depend on climate, usage, size, and quality of construction (and whether airtightness, windows, and thermal bridges are properly implemented).
Continuous comfort
More stable indoor temperature, fewer drafts, and fewer cold or hot spots, because the envelope reduces temperature "peaks."
Health and indoor air quality
Ventilation with filtration helps maintain cleaner air and constant renewal, which can be especially useful if you are sensitive to dust, pollen, or pollution.
Sustainability and environmental footprint
Reducing demand and consumption means less energy is needed for air conditioning. The final impact also depends on the materials, construction, and source of energy, but the "design-based" approach to efficiency usually improves the overall balance.
Standard requirements for a home to be considered "passive"
Beyond a stamp, there are practical requirements that are usually present:
Coherent thermal design (orientation, compactness, sun protection).
Construction detail for insulation continuity and thermal bridge control.
Weatherproofing plan (layers, seals, installation passages).
Windows/doors that meet energy efficiency standards and are properly installed.
Well-designed and well-distributed ventilation.
Execution control (precision on site is part of the "system").
Passive houses or Nearly Zero Energy Buildings?
A nearly zero-energy building aims for a very high level of energy efficiency, usually linked to regulatory requirements and reduced consumption. Passivhaus is a design/certification standard with specific criteria focused on demand, airtightness, and overall performance.
In practice:
A passive house is usually a way of achieving very low energy consumption by design.
A nearly zero-energy building can be achieved in different ways (combining efficiency and, in some cases, renewable energy sources), depending on the applicable framework and the project.
How much does it cost to build a passive house?
It may involve an initial additional cost compared to a conventional home, mainly due to:
best carpentry,
more detail on insulation and airtightness,
ventilation with heat recovery,
and execution control.
This difference can be offset over time by lower consumption, but it depends on the price of energy, the climate, usage, and the final quality of the work.
Which items tend to have the greatest impact on the budget?
| Departure | Why it matters | How to control it without losing performance |
|---|---|---|
| Windows and doors | They are critical points of loss. | Choose features that are appropriate for the climate and take care of the installation. |
| Airtightness | Requires detail and execution time | Define waterproof layer and plan installation steps |
| Continuous insulation | Prevent losses and cold spots | Resolving "difficult" encounters from the project |
| Ventilation with heat recovery | Equipment + ducts | Correct dimensioning and simple layouts |
Can you build a passive house in Spain?
Yes. The approach can be adapted to different climates (Mediterranean, continental, etc.), provided that the design responds to local conditions and overheating in summer is controlled. The decisive factor is not "the label," but rather that the home is well designed and built according to passive design criteria.
Renovation: converting a home into a "passive" home (EnerPHit)
In deep renovation, we often talk about EnerPHit, a variant applied to renovations. It usually involves:
reinforcement of insulation (often on the outside, if feasible),
replacement or improvement of carpentry,
reduction of thermal bridges where possible,
improved airtightness,
incorporation of mechanical ventilation.
The same level as in new construction is not always achieved, but significant reductions can be made if the scope is well defined.
Who certifies that a house is passive?
Passivhaus certification is issued by the Passivhaus Institut (or accredited entities/technicians, depending on the certification system). To be certified, the project must meet technical requirements and undergo verifications such as airtightness tests (blower door test) and energy demand checks using calculation tools.
If there is no certification, a home can apply passive principles, but it is advisable to request evidence: energy report, airtightness details, test results, and actual window/insulation specifications.
How to know if a passive house is right for you
It is especially suitable for you if you prioritize:
stable comfort (fewer temperature spikes),
less dependence on air conditioning,
indoor air quality,
lower energy costs over time.
Before deciding, consider these questions:
Does the design take into account sun protection and the risk of overheating?
Are there clear details for thermal bridges and airtightness?
Are leak testing and construction inspection included?
Is the ventilation realistically sized and distributed?
You save as much natural gas and electricity as they say.
The savings can be very high, but they are not automatic. They depend on the climate, the size, usage habits, the actual performance of the ventilation, and, above all, whether the insulation, seals, and windows are properly installed. If these points fail, the result will be far from what is expected.
Common mistakes that complicate execution
Design "passively" but without construction details for thermal bridges and airtightness.
Investing in equipment but neglecting the building envelope (windows/insulation).
Do not plan installation steps and then drill through the waterproof layer.
Ventilation that is poorly sized or has complex layouts that generate noise or leaks.
Failure to control overheating in summer (shading, orientation, internal gains).
Frequently Asked Questions
What is a passive house?
A passive house is a home designed to minimize energy consumption through efficient design, good insulation, and use of solar energy.
How much energy does a passive house save?
A passive house can significantly reduce energy consumption for heating and cooling thanks to its design and thermal efficiency.
Is it more expensive to build a passive house?
The initial cost may be slightly higher, but the long-term energy savings usually offset the investment.
Can a home be renovated to make it more efficient?
Yes. Through energy retrofitting and improvements to insulation, windows, or ventilation systems, the efficiency of an existing home can be improved.
Would you like to design an efficient and sustainable home?
Author
Cabana Team
Author information