Building a Passive House on a Budget

Building a house is always a strenuous and complex process. Whether you build the conventional way or the Passive House way, your budgeting will need to be precise. As anyone in the building industry will tell you, small problems can easily escalate and throw your minutely calculated budget out the window. Just watch one episode of Grand Designs and you will get an idea of what we are trying to express here.

All things considered, the sheer variety of tools and methods employed by the Passive House standard will allow you to keep within budget as much as possible and still end up with the energy efficient and low carbon footprint home you wanted.

The aspect that deters most people from considering going Passive House with their home is the slightly higher upfront cost. On average this stands at around 8%. However, with a smart and intelligent design, this percentage can level down to the kind of costs you see with conventional buildings.

What certainly works in favour of the Passive House approach is that, essentially, it is a quality standard. It dictates no particular method of construction. Designers can go the solid construction, composite, or even wood route. All this can only have beneficial effects on your budget.

The best way to show you how this can be done, in our opinion, is by presenting case studies of homeowners that successfully used the Passive House standard to build their home and not blow their budget in the process. Particular focus will be given on lessons learned and best practice.

To make things even more interesting, the case studies will be from three different countries: Ireland, the USA, and Australia.

Passive House Budgeting – the Ireland Case Study

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This particular pair of homeowners had a modest wishlist for their home. They wanted a bright, healthy, warm in winter, cool in summer kind of house. They also had a more long term vision, wanting their house to be future proof against changes in building regulations and rising energy costs. When you throw in the mix their desire for high indoor air quality, it is no wonder that they gave the Passive House standard a great deal of attention. What will follow is a list of lessons to take from this particular case study:

Getting Familiar With the Passive House Planning Package (PHPP)

One of the first things learned in this case was to try and trust the software behind the PHPP. Essentially, PHPP can be classed as a giant spreadsheet which allows you to meticulously calculate every step of the building process and make sure you remain within the requirements of the Passive House standard.

It does so by instantly showing the impact on energy efficiency of the decisions taken in the designing process. This way, depending on the type of building, you will know how much insulation needs to be used, the right amount and quality of the windows, cutting costs there adding some over there until you reach the right energy consumption per unit area and still stick to your budget.

Really Consider if ‘Green Bling’ Is Needed

The homeowners in this case chose to move away from implementing too many gadgets falling under the ‘green bling’ category. They decided not to opt for heat pumps, solar panels or even rainwater harvesting.

What they chose to do instead is rely on wood sourced locally for their hot water needs and heating in the winter. In the summer, hot water is provided by the immersion heater which in this case is used for only one hour each day.  

Stay Away From Conventional Thinking

The issue that provided the owners with the most headache is central heating. Particularly whether or not to install one.

The conventional thinking would dictate that there is no way of building a house in Ireland without any kind of central heating. However, with Passive House you simply do not need one.

As the owners mention, everybody was an expert with regards to this and they have been advised to install one just in case. In the end, they stuck with their Passive House design and their PHPP measurements and decided against it. The result was crucial savings in an already tight budget.

Lessons Learned From the USA

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The USA case study is all about a pair of first time builders. The homeowners in question have decided to opt for the Passive House standard for their inaugural step on the property ladder. Their home is located in Thaxton, Virginia. Following is a list of key lessons to take away:

Take Your Time And Do a Thorough Research

As you would expect, being first time builders, this pair of homeowners have had a hard time trying to get their head around the technicalities of a Passive House. Although what they wanted sounded nice, an energy efficient home at competitive prices, getting there meant learning the ins and outs of the whole building process to make sure that informed decisions are made and that they are not being pushed aside from the project.

Research was key prior, during, and even after construction. As the Passive House method often changes by way of new materials and techniques being developed, it means that you need to be committed to always being in the know.

The Importance of Choosing the Right Materials

Choosing the materials used during construction can have a bigger financial impact than the actual decision of building to the Passive House Standard. You need to be prepared for quality materials to cost more. However, it will be worth it in the end when you see that your home falls within the requirements to be a certified Passive House.

Help From an Unlikely Source

We must admit that this piqued our interest when we glossed over it. It seems that in this particular case, help came from an unlikely source. A local renewable energy association, the Roanoke Renewable Energy Electric Vehicle Association, heard about the pair’s Passive House commitment for their home and installed their solar thermal system free of charge.

Therefore, do not be quick to dismiss volunteer organisations. You never know from where a helping hand to your budget can come from.

Budgeting ‘Down Under’ – an Australian Case Study

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With this case study, we are going to change the scenery to a Melbourne suburban street suddenly filled with the hustle and bustle of building a certified Passive House on a modest budget. Key takeaways of this endeavour below:

Choose Proactive Builders

Taking advantage of their previous experience as owner-builders, this particular pair of Passive House enthusiasts were able to track down a local traditional builder keen to give it a go.

With their proactive stance during the construction process, they were able to work together with the builder and bring the costs of construction down to an impressive $2,100 per square metre. Compared to the typical prices of a Passive House build of $3,000, their achievement is even more impressive.  

Note: We highly recommend engaging a certified Passive House builder early on in the design and construction process. There is a lot of specialised knowledge that we have found is not covered or taught in the Australian building standards. Trust us, it will make your experience a whole lot easier and enjoyable.

Window Placement Needs to Be in Tune with the Shape of the Building

When it comes to building a Passive House, extra care needs to be given to the quality of the windows used and their placement around the house. Done right, this can solve the air leakage issue and also provide a comfortable and bright environment to live in.

In this case, the house is U shaped and allows natural light into each room. Windows were carefully positioned around the courtyard with good eaves and shading. The homeowners opted for argon filled double glazed uPVC windows which are known to achieve excellent insulation.

Budgeting Problem Solved?

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It goes without saying that there is no sure-fire way of building a Passive House within budget every single time. However, if there are some key lessons to take away from the above, these would be to:

• Trust the process
• Engage with the builders and designers throughout construction
• Do your homework
• Not give in to conventional building stereotypes
• Take extra time when choosing the materials
• Be open to suggestions and help from others
• Draw on your experience whenever possible

The silver lining for future Passive House homeowners would be that the number of designers and tradespeople properly trained in the ways of Passive House is steadily increasing. This is mostly due to the dedication of training academies and their perseverance in spreading the word.

If you are still not sure about whether a Passive House is right for you and your budget or you would like to know more about the benefits of sustainable living, feel free to click here for more information.

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