Passive House
Very high comfort with extremely low energy use. Especially cost-effective for new buildings: the slightly higher upfront cost is recovered quickly through energy savings over the building's life.
A warm, healthy building that barely needs heating.
Passive House is a performance standard: get the building fabric right first, verify it on site, and the energy bill takes care of itself.
Tap one of the five core principles to see where it lives in the building.
What is a Passive House?
Fabric first. Measured, not promised.
Passive House puts the building fabric first. It combines a clearly defined performance standard with a quality management system, so the finished building is comfortable and healthy for the people inside while using very little energy — with no need to burn fossil fuels.
The Passive House Institute (PHI) developed two building standards, Passive House for new builds and EnerPHit for retrofits. Both rest on sound building physics and applied research, with specific criteria that make quality reliable.
Anyone can build a Passive House or retrofit an existing building to EnerPHit, and both are now popular worldwide — for homes and most non-residential buildings, from offices to schools and swimming pools, in every climate zone.
Designing a Passive House
The standard is known for predicting how a building will actually perform once it's built. That depends on a rigorous design process, proven methods and checks on site. Designers need a solid grasp of how energy moves through a building, and a validated tool to quantify and balance those flows.
Orientation and shading
A Passive House doesn't rely on the sun to stay comfortable, but sun paths and shading still deserve careful thought. The goal: solar gains that help meet the targets, without tipping the building into overheating.
Form factor
The shape of the thermal envelope affects how much insulation you need. A larger envelope loses more heat per square metre of usable floor, and a complicated shape adds junctions that are hard and costly to detail. Keep the form simple.
Insulation and thermal bridges core principle
Every part of the envelope must be well insulated. Options range from batts and straw bales to SIPs and vacuum panels; the right material and thickness depend on the local climate. Edges, corners, connections and penetrations need particular care to avoid thermal bridges.
Windows and doors core principle
High-performance windows and doors are arguably the most important thing to get right. Passive House certified windows come in several frame materials and must meet strict thermal and airtightness criteria.
Airtightness core principle
Airtightness is central to certification and, above all, a strong indicator of build quality. A leaky building isn't automatically "breathable", and an airtight one isn't automatically bad at handling moisture. Designers need to understand how these mechanisms interact — and where they're independent — to deliver an airtight building with a healthy indoor climate and a robust, vapour-open envelope.
Ventilation core principle
A good envelope keeps you warm; good ventilation keeps the air fresh. The standard doesn't strictly require mechanical ventilation, but controlled ventilation with heat recovery (MVHR) is the easiest route to the energy targets in hot and cool climates, and a precondition for reliable indoor air quality anywhere.
Hot water and heating
Heating systems in Passive Houses are much smaller than most people expect. Small heat pumps, direct electric heating or conventional boilers can all work. Oversizing wastes money and efficiency — keep the system small, efficient, responsive and simple.
Software: PHPP
The Passive House Planning Package (PHPP) is the all-purpose tool for Passive House modelling and design. It shows the effect of design changes accurately and immediately. Beyond some extra care to protect performance, designing a Passive House follows much the same steps as any other project. Planning tools at PHI
Certifiable building standards
New buildings certify as a Certified Passive House; refurbished buildings certify to PHI's EnerPHit retrofit standard. A third standard covers buildings that came close.
EnerPHit (“Ener-fit”)
The standard for energy-efficient retrofits of existing buildings using Passive House components. Because existing structures often make the full standard hard to reach, it allows slightly higher energy use — as long as every comfort criterion is still met.
- Proven by the energy demand method or the building component method
- Step-by-step retrofits possible with an EnerPHit Retrofit Plan, which can be pre-certified
PHI Low Energy Building
For buildings that aimed for Passive House but just missed it — for example because they didn't meet the airtightness requirement.
In development — pilot projects welcome
EnerPHit Unit
A variant of EnerPHit (component method) for certifying a single retrofitted residential or commercial unit in a multi-unit building. The unit must meet all EnerPHit Classic component-method requirements, except:
- Airtightness: met when air permeability qE50 ≤ 1.0 m³/(h·m²)
- Primary energy: if heating, cooling or hot water is centralised, the PER check can assume a hypothetical future heat-pump supply
Connections to neighbouring conditioned spaces must not raise mould risk, and must let the insulation layer continue if the adjacent unit is renovated later. The rest of the building isn't assessed.
In development — pilot projects welcome
Core & Shell
For non-residential buildings suited to office use that the owner leases out partly or fully as core & shell. Besides the complete thermal envelope, the building must include at least:
- Ventilation, heating, cooling and hot-water units with vertical distribution
- Lighting in common areas, lifts, and external shading if needed
Tenants install everything else, following a document of technical minimum requirements for tenant fit-out (TMRT) that forms part of the lease.
Preliminary criteria for both are available on request and can already be used for certification with written confirmation from the certifier and PHI.
Classic, Plus and Premium
Passive House and EnerPHit pair naturally with renewables. Adding on-site generation is strongly recommended, and it's reflected in the certification class. The class compares the whole building's renewable primary energy (PER) demand — heating, hot water and household electricity — with the renewable primary electricity it generates.
Classic
Passive House or EnerPHit without renewable generation.
Plus
Over a year, the building generates about as much energy as it uses.
Premium
Over a year, it generates significantly more than it uses.
How certification works
Certification is done by an independent third party against quantifiable, science-based minimum requirements. It's the only way to be sure a building really delivers: excellent air quality, a comfortable indoor climate and reliably low energy costs. It also adds to the property's value.
Consultation
The certifier helps improve the design for energy efficiency and cost-effectiveness. The earlier they're involved, the smoother and cheaper the project. Certifying after completion is still possible if the building meets the criteria.
Design review
The implementation plan is reviewed in full, and the energy balance calculation is checked.
Corrections
The certifier points out anything that needs to change to meet the criteria.
Construction evidence and final inspection
Quality control is completed with an airtightness test, the ventilation system's commissioning protocol and the site manager's declaration.
Certificate
Issued only if every criterion is met, without exception. A house plaque is available on request.
Retrofitting step by step
Many owners prefer to replace old building components gradually rather than retrofit everything at once — and this is the most economically viable way to do it.
Before the first step, draw up an overall plan covering every stage through to the fully retrofitted building. That's the only way to make sure each step fits the next, so you end up with a cosy building and low energy costs.
EnerPHit Retrofit Plan (ERP)
Included in the PHPP tool, the ERP gives you that overview. PHI can also pre-certify the project as EnerPHit (or even Passive House) once two conditions are met:
✔ a carefully prepared EnerPHit Retrofit Plan
✔ the first retrofit step is done, saving at least 20% energy
The pre-certificate gives owners and designers confidence that the target standard will be reached once all steps are completed as planned.
Find help
PHI's team and certified Passive House designers, consultants and tradespeople worldwide can advise on your project, new build or renovation. In New Zealand, PHINZ lists local professionals.
Choosing a certifier
Certifiers don't have to visit the building, so you can pick one anywhere. PHI certifies Passive House, EnerPHit and PHI Low Energy Building projects worldwide, alongside certifiers it has accredited.
Passive House Institute — GermanyLanguages: de, en, es, it, pl, bg, zhbuilding.certification@passiv.de
+49 6151 82699-0
+49 6151 82699-0
Passive House Institute — AustriaLanguages: de, en, huoffice@phi-ibk.at
Building criteria
The official criteria cover Passive House, EnerPHit and PHI Low Energy Building.
- Building Criteria v10cEnglish, SI units
- Building Criteria v10cEnglish, IP units
- Gebäudekriterien v10cGerman
- Criterios para edificios v10cSpanish
- Other translationsPartner translations
Third-party translations aren't verified — certification is always based on the official English, German or Spanish criteria. Projects that started certification in April 2023 or earlier use the criteria in force at the time (archived versions 10b, 10a, 9f and earlier are on the PHI site).
Using the Passive House logo, seal or plaque? Follow PHI's usage guidelines.
Keep learning
Hear from New Zealanders who live in Passive Houses, browse certified buildings worldwide, or dig into the basics.