This is a Passivhaus Basics blog post that gives an overview of a specific aspect of the Passivhaus Standard.

The Passive House Planning Package (PHPP) is one of the most powerful design tools available for designing low energy buildings. It can seem intimidating as an extensive programme of interlinked worksheets, typically used in Micorsoft Excel. However, when viewed worksheet by worksheet is it apparent how straightforward it is.

It is a necessary part of Passivhaus design, both for Passivhaus Designers and Consultants and for Passivhaus Building Certifiers. For designers, it is a useful tool at all stages as detail is gradually built up. And it provides a large degree of the all-critical quality assurance of the international Passivhaus Standard. And finally it is the tool used for certification of a Passivhaus Building.

At it’s most basic, the Passive House Planning Package (PHPP) is a collection of clearly defined building physics algorithms. When the required information is entered, accurate reliable results are produced. And it continues to be developed as the Passivhaus Standard evolves and the world transitions towards a renewable energy future. (No matter how slow that transition might seem to be going currently!)

The Passive House Planning Package (PHPP): design tool, quality assurance tool and certification tool + all the essential building physics a low energy building needs.

What is the Passive House Planning Package (PHPP)?

The PHPP is a software programme created by the Passive House Institute. The programme is a series of interlinked worksheets that work in commonly available spreadsheet applications such as Microsoft Excel and OpenOffice Calc.

The PHPP is at once a design, verification and certification tool. The PHPP is not a compliance tool to be filled out after the design is complete, though.

There is a “Brief Instructions” worksheet at the beginning and then the remaining worksheets in the PHPP are in 4 categories:

• Verification
• Heating
• Cooling
• Primary Energy

The Brief Instructions worksheet gives a key to the way different cells in the worksheets are coloured, which makes it clear where you need to enter information as opposed to where the PHPP will report results. It also contains a directory of all the worksheets that lists the worksheet title, function, description and whether or not it is required for certification

The Verification category contains 2 worksheets; Passive House Verification and PHPP Check. There are some other hidden worksheets in this category that can be shown if variants are going to be explored within the PHPP.

The Verification Worksheet is where general project information is entered and some details about the specific type of project it is. Such as if it is residential building and if it is a new build (Passivhaus) or a retrofit (EnerPHit). It is also where the key Passivhaus metrics are reported (Spacing Heating Demand, Heating Load, Space Cooling Demand, Airtightness, Primary Energy etc) and verified as meeting the standard, or not.

The Check Worksheet collects together a summary of which worksheets have errors. There are hyperlinks to take you to the worksheet in question making it easy to track down errors. Each worksheet has an error column on the left-hand side to simply flag up an error and another column the right-hand side that states the nature of the error (e.g. missing or incomplete data). Some worksheets also have a column for warnings. These provide guidance when something doesn’t appear correct.

The Heating Category has twelve worksheets; Climate, U-values, Areas, Ground, Components, Windows, Shading, Ventilation, Additional Ventilation, Annual Heating, Heating and Heating Load.

This category of worksheets is where a lot of the architectural design of the building gets entered.

The Climate Worksheet is where the building location is set, including the country, the region, the specific climate data set and the building altitude. Getting the altitude incorrect can make a significant difference to the results, which demonstrates just how climate specific Passivhaus design is.

The U-values Worksheet is where all the different construction assemblies are entered so that the thermal conductivity of each is calculated. The calculations are transparent and obvious so different assemblies can easily be tested. It is also possible to set up multiple assemblies and swap where they are used in the later worksheets to check the results and optimise the assembly specification.

The Areas Worksheet is where the geometry of the building is entered. This includes the Treated Floor Area, all external wall, ground floor (or basement ceiling) and roof surfaces. The different assemblies entered are linked back to the assembly types on the U-values worksheet. As well as areas, angles and slopes are entered for each assembly. Thermal bridges are also entered on this worksheet.

The Ground Worksheet is used to calculate more accurately what the heat loss through the ground slab will be. It takes into account the building geometry and the capacity of the below-slab ground material to both transmit and store heat.

The Components Worksheet is where the performance characteristics of critical building components are entered. If Passive House Institute certified components are being used, these can be selected from a list with all the required data pre-populated. The components to include are; glazing, window / door frames, MVHR units, compact units with exhaust heat recovery, and domestic hot water heat recovery units.

The Windows Worksheet is where all the windows (and glazed doors, curtain walling, rooflights etc) are entered. The dimensions, orientation, what building assembly they are installed in (from the areas worksheet), the glazing and frame (from the components worksheet) and the installation situation (i.e. in a wall / roof, or adjacent another window) are all needed. The worksheet reports the total areas and the energy balance of glazing in each main direction (i.e. what is the annual difference between the heat loss and the solar heat gain for each direction.)

The Shading Worksheet is essentially a second windows worksheet. The windows entered on the previous worksheet are reported here so that horizontal and vertical shading conditions can be entered. Shading details include how deep a window is set into a wall.

The Ventilation Worksheet is where the type of ventilation and the corresponding details are added. There is a choice between balanced heat recovery ventilation (i.e. the typical situation in a Passivhaus building), mechanical extract ventilation and window ventilation (i.e options that might suit very favourable climates, or might be necessary for a retrofit.) The ventilation unit from the components worksheet can be selected and then various other aspects need to be entered. These include the use pattern (i.e. how many hours a day it runs on each speed), the design air flow rates, whether the unit is inside or outside the thermal envelope, and the size, length and insulation of ducts carrying fresh air and exhaust air (i.e. outside temperature air). Once all the data is entered the worksheet reports back the efficiency of the MVHR unit as it will be in the design.

The Additional Ventilation Worksheet is used when balanced heat recovery ventilation is selected and there are multiple ventilation units. This would typically be for multi-unit residential buildings and non-residential buildings.

The next 3 worksheets, Annual Heating, Heating and Heating Load, essentially report the results of all the heating category. The headline figures from these worksheets report back on the verification worksheet.

The Annual Heating Worksheet gives the space heating demand (kWh/m²a) using annual climate data and also includes a heat balance graph. The heat balance graph is a very useful visual indication of where the heat is lost and gained in the design. For example, is more heat lost through the ventilation system than through the windows or through the external walls? Or, on the other side of the graph, is solar heat gain far greater than internal heat gains and therefore, introducing a potential overheating risk? Seeing the balance of heat gains and losses all proportionate to each other is very instructive for design development.

The Heating Worksheet gives the space heating demand (kWh/m²a) using monthly climate data so it is a little more granular. It also takes into account thermal storage capacity from thermal mass in the building. As well as the heat balance graph, there is a graph illustrating specific heat loss and gain each month (solar and internal heat gains combined) and therefore what the specific heating demand is for each month. This gives a good overview of the heating season for the design.

The Heating Load Worksheet reports the nominal maximum heating load (W/m²) in two scenarios. These are a cold cloudless day and a moderately cold overcast day, either of which could result in the ‘worst case scenario’. The results of this worksheet indicate whether or not the heating could be provided through the ventilation system (i.e. is the peak load below 10 W/m².)

The Cooling Category has 5 worksheets: Summer Ventilation, Summer, Cooling, Cooling Units, Cooling Load.

The Summer Ventilation Worksheet is where more granular details of the ventilation design are entered. It also provides the results of passive cooling measures in the form of an overheating frequency. Summer ventilation can be provided solely by the MVHR unit, or the MVHR unit in combination with opening windows. Additionally, the MVHR unit can have an automatic summer bypass (no heat is recovered from extract air) or a manual bypass or no bypass at all. There is also a section to include additional ventilation such as night ventilation (cooling) via windows, or other mechanical ventilation. While it is possible to put the ‘best case scenario’ in for the ventilation design, how the people in the building will realistically make use of the ventilation system must be taken into account. There are also some tools to calculate cross ventilation effectiveness.

The Summer Worksheet is solely a results sheet for overheating making use of passive cooling measures. (The same figure as on the previous worksheet.) It indicates much more of the workings and comfort aspects while also including some temperature graphs across the year.

It should be noted that for more granular overheating checks, such as on a per room basis, or for buildings other than a single-family residence, tools outside of the PHPP should be used. For example, if the design has considerable west facing glazing in one room of the building (a clear overheating risk), the PHPP might not indicate a high frequency of overheating. This is because the PHPP considers overheating across the whole building and won’t pick up where a single room might have a greater risk.

The Cooling Worksheet is equivalent to the heating worksheet but for the cooling season, if one exists for the project. It gives the annual useful space cooling demand (kWh/m2a) and includes monthly graphs showing clearly when the specific cooling demand occurs. If some overheating occurs but the frequency is considered acceptable, the space cooling demand will be very low and no active cooling system will be required. The international Passivhaus Standard requirement for space cooling demand is the same as the space heating demand: 15 kWh/m²a.

The Cooling Units Worksheet is where any active cooling systems are entered. These could include; supply air cooling, recirculation cooling (air-conditioning), panel cooling. With panel cooling, such as thermally activated concrete surfaces (where a cool liquid is circulated in the concrete), additional dehumidification might also be required to avoid surface condensation. This worksheet also includes humidity loads and the energy demand of dehumidification.

The Cooling Load Worksheet is equivalent to the heat load worksheet but for cooling. It is also different in that it calculates the daily average cooling load. Along with the cooling load, the daily internal temperature swing is calculated and the dehumidification load also. Similar to the heat load, the cooling load indicates whether or not the cooling could be provided through the ventilation system. The international Passivhaus Standard requirement for cooling load is the same as the heating load: 10 W/m².

The Primary Energy (PE) category, has 16 worksheets; Domestic Hot Water and Distribution, Solar Domestic Hot Water, PV, Electricity, Non-residential Utilisation, Auxiliary Electricity, Internal Heat Gains, Internal Heat Gains for Non-Residential, Primary Energy Renewable (PER), Heat Pump, Boiler, District Heating and Data. This category of worksheets it largely about entering the details of the systems used in the design. Therefore, only the relevant worksheets are necessary to be used.

In many cases, these worksheets will only get filled out once the design has progressed significantly. In contrast, it is essential that the heating worksheets are used from the very beginning of the design process because of all the building geometry and architectural design encompassed.

The Domestic Hot Water and Distribution Worksheet is where hot water pipe and distribution details are entered. The heat losses from the distribution of both heating water and domestic hot water are calculated, along with the useful heat gain from domestic hot water use. (Taking a shower helps to heat your house.) On a larger design (e.g. multi-unit residential blocks), distribution lengths can make a significant difference in energy consumption and internal heat gains, this is an important worksheet.

The Solar Domestic Hot Water Worksheet is where details of a solar thermal system can be entered if one is included in the design. The system gets linked to the location of other building elements (e.g. the roof) that have been entered into the areas worksheet. There is a section to add solar collector systems much like the components worksheet, or there are some generic system types included with suitable data to use. There is also guidance on correctly sizing a solar thermal system for the design.

The PV Worksheet is where details of a PV system can be entered. Like the solar thermal system, the PV modules get linked to the location of other building elements that have been entered into the areas worksheet. The PV module type can be selected and relevant data entered, or a typical module type can be selected along with the suitable data.

The Electricity Worksheet is where all the different uses of electricity are brought together. Domestic appliances (‘white goods’), lighting, consumer electronics, small appliances are all entered along with suitable utilisation factors. The electricity use of pumps and fans in the mechanical systems are reported back from the Auxiliary Electricity Worksheet and included in the total. Some of the calculations on this worksheet are dependent on occupant numbers entered on the verification worksheet, so it is important that the number of people is entered accurately. Some of the values are standardised by the Passive House Institute to ensure reasonable and comparable figures are used. (E.g. washing machine electrical demand is based on a 5kg load as standard.)

The Non-residential Utilisation Worksheet is for entering utilisation patterns for non-residential buildings. For example, classroom hours for a school, or office hours for a workplace.

The Electricity Non-residential Worksheet is for entering room by room artificial lighting information. Utilisation patterns from the previous worksheet are available as a drop-down menu for each room. More detailed electrical equipment is also entered on this worksheet including computers, monitors, copiers, printers, telephone systems etc. along with a section for commercial kitchens.

The Auxiliary Electricity Worksheet is where details are entered of electrical equipment associated with the ventilation, space heating, domestic hot water, cooling and dehumidification. This is where the power consumption of MVHR fans, defrosters and hot water pumps are entered, for example. If the design includes other electrical equipment such as lifts, these also get entered in this worksheet. The worksheet also calculates the heat output of these systems, which feeds into the internal heat gains total.

The Internal Heat Gains Worksheet collects together all the heat from internal sources throughout the design. These include electrical equipment, lighting, cooking, hot water distribution and the people. Hot water distribution doesn’t get factored into beneficial winter heat gains, otherwise this might incentivise designing inefficient systems! It does get included for summer overheating though as it could easily be a critical factor. Internal heat gains will often make up around a third of the total heating of a residential design – the other two-thirds coming from solar gain and the heating system.

The Internal Heat Gains for Non-Residential Worksheet is the same as the previous worksheet but for non-residential designs. It also references back to the non-residential utilisation worksheet for selection of utilisation profiles. On larger designs where there are more people in the building and more electrical equipment, an office, for example, the internal heat gains will make up a greater proportion of the heat balance than a third and solar gains need to be carefully controlled.

The Primary Energy Renewable (PER) Worksheet collects together all the energy consumption of the design from the other worksheets. The energy from each source is multiplied by a primary energy renewable (PER) factor to arrive at the primary energy renewable specific value, in the case of renewable energy sources. Energy from non-renewable sources is multiplied by a primary energy (PE) factor to arrive at the primary energy specific value This is to take account of losses from generation and distribution etc. and for utilisation of renewable energy.

For example, natural gas in the UK has a PE value of 1.1. This means that for every 1 unit of energy used in the design, 1.1 units of source energy are required. In contrast, electricity from the grid in the UK has a PE value of 2.6.

The PER Worksheet also reports CO₂ emissions in kg/m₂a.

The Heat Pump, Ground Source Heat Pump, and Boiler Worksheets are all fairly straightforward worksheets for entering the details of the specified equipment.

The District Heating (and CHP) Worksheet is where the heat loss through distribution and storage associated with a district heating system are entered. This generates the final energy demand and primary energy renewable specific value for the district heating.

The Data Worksheet is where all the Primary Energy Renewable (PER) and Primary Energy (PE) Values are listed, as well as CO₂ factors referencing the Global Emissions Model for integrated Systems (GEMIS) database. There are columns available for alternative PE factors and CO₂ factors to be entered also. In most cases there is nothing to enter on this worksheet.

The Passive House Planning Package (PHPP): a detailed programme of interlinked worksheets that provide everything needed to design a building to the international Passivhaus Standard.

Why use the Passive House Planning Package (PHPP)?

At some stage, every Passivhaus design must be entered into the PHPP. However, the best use of the PHPP is as a design tool throughout the process.

The PHPP is used from very early in the design process to build up a useful interactive understanding of the design. Initially only limited information is entered into the PHPP, aligned with the level of design development. During the design process, options can be tested and checked to see instantly what the results on the performance will be.

Once the design is relatively stable further detail is entered into the PHPP, developing a more granular picture of how the building will perform. At this stage, various aspects of the design can be tested in more detail. Testing elements can lead to an optimised solution for both the design aspirations and building performance. The architect or designer can understand from the PHPP which aspects of the design have the most impact on the performance and therefore, make intelligence choices.

Throughout the design process, the PHPP reports accurate and useful indications of performance. There is no longer a need to guess how a particular design decision will affect how comfortable a space will be, or what energy bills will result.

Once the design is being constructed, any proposed changes in component or materials specifications can be feed into the PHPP. Again, an accurate picture of the impact is instantly available. Suggestions and alternative proposals made during construction might have good reasons but equally might have detrimental effects on the building performance. With the PHPP, the effects can be checked swiftly and with accuracy.

The PHPP does require detailed information to be built up during the design process, it is accurate enough to be useful at each stage. It isn’t a ‘rapid energy modelling’ tool that gives rough outputs that don’t correlate to real world performance. Genuine sustainable design requires work; it is simple but not necessarily easy.

Does a spreadsheet-based tool restrict creativity? Passivhaus does bring further constraints to a design, but the spreadsheet aspect of PHPP need not influence the creative process. Perhaps it does drive simplicity in some cases, but creativity and simplicity can go together beautifully. (As many consumer electronics demonstrate!)

Aside from the design process, the PHPP also predicts comfort and energy consumption very accurately for Passivhaus or low energy buildings. (Nothing can provide accurate predictions for buildings that are not low energy.) The accuracy of the PHPP is partly how the international Passivhaus Standard has effectively eliminated the performance gap.

The Passive House Planning Package (PHPP): an accurate and useful design tool

How does the Passive House Planning Package (PHPP) work?

The PHPP works for two primary reasons; it is based on the laws of physics and it is continuously developed and refined.

As stated on Passipedia:

Wherever possible, specific algorithms resort to current international standards. Generalisations are necessary in some places (e.g. global established routines for shading), and sometimes deviations may also be necessary (due to the extremely low energy demand of Passive Houses, e.g. for the asymptotic formula for the utilisation factor), while for some areas there are no internationally relevant standards (e.g. with reference to dimensioning of ventilation systems). [Source]

The PHPP was developed specifically for low energy buildings and because of this it is a more accurate tool for modelling and predicting the performance of low energy buildings than conventional methods.

The PHPP was subject to extensive validation and checking against dynamic modelling and equally importantly, against measured results in completed buildings. Since the first edition of the PHPP was released in 1998, various new modules have been added over time to get to the current version (9.3) referenced in this blog post. Validation against measured results from completed buildings continues the development of the PHPP. And so do scientific findings that get presented regularly at the annual International Passivhaus Conference.

The Passive House Planning Package (PHPP): reliable physics and quality assurance for certification

The Passive House Planning Package (PHPP): a detailed, open and reliable building physics model.

The Passive House Planning Package (PHPP) is the programme that must be used to design and certify Passivhaus building. It encompasses the specific climate where a design is situated, the building geometry, building assembly specifications, the heating, cooling, ventilation, lighting and all other energy uses within the building. It is a thorough and detailed building energy model that gives reliable and useful results.

And yet, it is also a versatile and dynamic design tool. It allows for iterations and variations to be tested. It allows for parametric design approaches to be developed. All the while, giving direct instant results from any change or tweak.

And it is all open. The calculations that are all done longhand in Passivhaus Designer courses are there to be seen and understood with the Passive House Planning Package (PHPP). Change a number and the effects are on display. Look closely and the units and mathematical functions are all there in each calculation.

Finally, the Passive House Planning Package (PHPP) provides quality assurance to the design and construction process and the means to achieving Passivhaus Building Certification.

We need to massively cut CO₂ emissions globally. And the way to massively cut CO₂ emissions from buildings, is to design buildings to meet the international Passivhaus Standard. To do so, you need to use The Passive House Planning Package (PHPP).

The Passive House Planning Package (PHPP): the tool for designing buildings with radically reduced CO₂ emissions.

Some additional resources:

• PHPP Illustrated: A Designer’s Companion to the Passive House Planning Package. Read my detailed review here.
• PHPP – Passive House Planning Package on Passipedia.

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