Deep Energy Retrofit With Passive House EnerPHit

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How To Make A Deep Energy Retrofit Part Of A Remodel

So, the enclosure of your home needs repair or more serious updates – your roof, exterior walls or windows? Maybe you even decided to retrofit one or multiple elements to make your home more energy-efficient?

And, you wonder how your home improvement project can maximize your home’s performance to benefit the health and comfort for you, your loved ones and the environment?

Or maybe you decided to do a deep energy retrofit to lower your energy consumption and release less greenhouse gases into the atmosphere.

No matter what your reasons for your home improvement project are, as long as you plan to touch the exterior structure of your home or a main mechanical system of your home you have a choice.

You can either stay merely in line with your local building code or you can go beyond building code and upgrade your home with high performance components and building practices to get maximum benefits as a result.

You will enjoy enhanced comfort, health, ultra-energy efficiency, and much more.

You might think well, doesn’t our building code ensure we have the best buildings that can be build?

Unfortunately, this is not the case. Depended on where you live, your building code might primarily focus on building safety and not necessarily on your enhanced comfort, health, energy efficiency, nor give much consideration to  the environment.

It’s a bit like choosing your food. You can just rely on any food approved by the Food and Drug Administration (FDA) or you can step it up, get educated what is healthy and good for your health and choose accordingly.

The FDA focuses on food safety but not necessarily the quality of the products offered in your grocery store.

Same is true in the building Industry!

Building to code is obviously a must and ensures building safety but it can also be the bare minimum, dependent on the state you live in.

It is up to us to strive for the building products, processes and professionals that provide us with the most benefits when we decide to make changes to our home’s enclosure.

Like with food choices, to make the most beneficial decisions for your home, you have to gain some basic building knowledge first.

That brings me to the Passive House Standard and its program for deep energy retrofits. It’s called EnerPHit.

The Best Deep Energy Retrofit Standard Is EnerPHit – The Passive House for Retrofits

Let’s look at the overall voluntary Passive House Standard first. It’s a great opportunity to learn how your house works and it is the foundation for EnerPHit..

The Standard provides guidance on how to close the gap between a standard code home and a high performance home for everything related to the design and construction of your homes’ enclosure and mechanical systems.

I am not saying you should become an expert but get a basic understanding about the 5 Passive House Principles and why they are so important to follow.

This article is a good start with links to more: What is the Passive House Standard?

For starters, here is a quick 90 seconds introduction o Passive House and its 5 principles:

How to apply the Passive House Standard to a Remodel?

While the Passive House Standard focuses on new buildings, there is an adjusted version available that takes the difficulties of an existing building into account. This version of the Passive House Standard is EnerPHit. 

EnerPHit addresses the challenges of a remodel that might have to deal with:

  • Existing architecture,
  • Fixed forms,
  • Fixed orientation,
  • Neighboring buildings,
  • Planning and conservation issues, and
  • Existing occupants.

EnerPHit is still founded on the original 5 Passive House Principles, but it acknowledges that it might not be possible to achieve them completely, e.g., we can’t do much about an uninsulated floor of a slab on grad home.

For that reason, EnerPHit comes with adjusted performance goals to take those possible limitations in the retrofit building into account.

As with everything else within the Passive House Standard, EnerPHit is based on building science, research and experience.

EnerPHit is one of the most stringent and integrated standards available internationally for energy retrofits. The EnerPHit Standard is based on the Passive House Standard, a tried and true approach to efficient building with over 20 years of positive examples to show and used all over the world for any type of building.

EnerPHit addresses a common dilemma for renovations:

It is mostly impossible to retrofit all parts of the enclosure at the same time. Most of the times it is financially and logistically not feasible to complete an entire deep energy retrofit in one step.

In fact, 80-90% of all retrofits undertaken are partial retrofit measures rather than complete one-time deep energy refurbishments. These partial retrofit measures are completed over time when the respective building component needs to be renewed anyway.

That is why EnerPHit provides guidance for both scenarios:

  • Retrofit all components of the building shell in one step to the EnerPHit Passive House Standard.
  • step-by-step approach to retrofit all components of the building shell over time, based on a schedule created at the time the first renovation step is planned.

To achieve cost efficiency, it is crucial to couple the high performance and energy saving measures with renovation measures that would have been necessary anyways.

The motto is: If you do it, do it right! 

Whenever a building component needs to be replaced:

  • the materials used and the workmanship involved should be of the highest quality possible,   
  • the 5 Passive House principles should be followed to the extend local climate requires, and
  • it should be assessed what impact, positive and negative, the changes to one building element might have on other ones. E.g. airtight measures and closure of attic vents might cause moisture if temperature difference in the attic are to big. That means it might be smart to airtight and insult the attic ceiling at the same time instead of the often done insulation on the attic floor.  

To get an idea how this can work, here is a great 6 minute video about a step-by-step retrofit of a family home. 

Home Performance Assessment

Before ever you ever start a project on your enclosure a home performance assessment is highly recommended.

Otherwise, how can you know how to best improve your home’s current condition if you do not have a data driven clear picture of its current condition?

So, get a health check for your house… It is called either a Home Performance Assessment or Energy Efficiency Audit.

Select a Certified Energy Auditor or Assessor to perform the home assessment. Here is a list of things a good auditor will do:

  1. Determines the  overall condition of your home:
  • for each of the components that make your exterior structure (roof, exterior walls, floor, windows and doors),
  • for the mechanical systems  (heater, air-conditioner, water heater, etc.) and
  • how effective all of these components work together as a whole house system.
  1. Runs safety checks and diagnostic testing to identify leaks as well as moisture and ventilation problems. This includes a so called blower door test to identify air leaks and thermal imaging with an infrared camera to detect breaks in the insulation layer.
  2. Conducts an interview with you and preferably all other occupants, to identify comfort specific issues as well as living pattern in your home. If you are planning a remodel a home you have not lived in yet, make sure you talk to the previous occupants and also get access to their energy bills or at least totals per month if possible.
  3. Reviews previous energy bills as a benchmark for projected improvements and savings.
  4. Provide you with a prioritized list of home improvement recommendation, prioritized based on health and safety issues, comfort and overall cost benefit.

This gives you a clear understanding of your buildings condition. It is always good to be in the knowing, even if it is not pretty!

It is money spent very well!

Purely anecdotal information, like ‘the upstairs bedrooms overheat while downstairs never gets warm’ won’t cut it. This comfort issue is important to know but it won’t tell you the real problem within the building structure and how you can improve it.

With this clear understanding of your home’s condition, you can make better decisions and incorporate these findings into your overall remodel plans.

This is where EnerPHit comes in handy and your Energy Auditor can help you get the EnerPHit process started.

How To Renovate With EnerPHit

EnerPHit LogoEnerPHit is a program that allows to plan and manage a deep energy retrofit over time, step-by-step. An overall plan will be prepared for the first and all subsequent modernization steps at the same time.

This is the only way to be sure that everything fits together, is most cost effective and you can count on having an increasingly more comfortable house with low energy cost over time.

The same benefits the regular Passive House Standard provides can be achieved with EnerPHit. Here is a quick rundown of the benefits again:

  • health,
  • comfort,
  • durability,
  • resiliency,
  • predictability,

and that does all this with

  • a lot less energy, like 75% less energy and
  • it seeks a balance with nature?

You won’t achieve this with the regular building code. 

If you like to read a bit more about the benefits you can find that in my post What is a Sustainable Home?

The EnerPHit Toolbox

The EnerPHit program provides a toolset to create a master plan, the so called EnerPHit Retrofit Plan (ERP).

The very first task in developing the ERP is to create a schedule that provides an overview of the chronological sequence of renovation measures that are necessary over the years anyways (e.g. new roof, renovating siding of house).

You should work with your Energy Auditor to fill out the schedule based on her/his final report. Here is an example of a timetable: 

EnerPHit Scheduler

This schedule is the first step in the EnerPHit Retrofit Plan, your well-thought out master plan for efficient and well-structured step-by-step retrofits. It is a great tool for you to discuss and plan with current and future architects and contractors.

An EnerPHit Retrofit Plan (EPR) is composed of:

  • the scheduler with all renovation measures over time, as outlined above;
  • more detailed information about the expected renovation measures and the added retrofit step;
  • project cost for renovation and retrofit measures as well as maintenance and energy cost;
  • quality and performance data of building components used;
  • performance indicators for EnerPHit criteria;
  • matrix with interdependencies between measures that need to be address;
  • detail drawings and explanatory notes.

If you sell your home, the ERP helps the new owner to understand the additional energy efficiency potential of the building and the measures associated.

It also documents what has been done already and how it has improved the home’s performance. This is definitely a great benefit for every buyer and might attract maximum price and a quicker sale.

Example of a step-by-step EnerPHit Retrofit designed to EnerPHit Premium certification: 

PH Energy Demand

The EnerPHit methodology and toolset can be used with or without intended EnerPHit certification.

EnerPHit Pre-Certification

On the other hand if EnerPHit certification by the Passive House Institute (PHI) is pursued, a pre-certification can be achieved for quality assurance and recognition.

A PHI accredited certifier will check the prepared EnerPHit Retrofit Plan for compliance with EnerPHit requirements, for completeness and consideration of all interrelations between all measures.

This way unnecessary project cost and ongoing energy cost can be avoided. After approval, the first set of measures can be implemented. Once the step is executed and approved by the certifier you will receive a pre-certification for the building.

A preliminary certificate might increase the value of your home because its potential is clearly demonstrated and validated by a third party. It also increases the credibility of the refurbishment concept in the context of talks with the bank e.g. because the achievable cost saving is available in a reliably calculated way.

With or without certification, a high-efficiency retrofit to the EnerPHit standard differs from standard retrofits in a higher quality of design, workmanship and construction components, which leads to a more comfortable building, higher energy efficiency and less CO2 emission.

Process of a EnerPHit certification over time – step-by-step:

EnerPhit Process

My thought on EnerPHit

A few years back when I attended my Passive House training I was blown away by the straight forward simplicity yet depth of the program. It has been developed by an independent research institute and is simply based on building science and physics.

We had architects, contractors, green building consultants and energy consultants at the class. Every single one of us left the training after 5 packed days with the same statement:

Duh! This is the way to build the best buildings possible. And why do we not build every single building by theses principles? It’s so straightforward! 

There are millions of buildings in the U.S. and around the world who need renovations over time. We could avoid an incredible amount of green house gas emissions and secure and improve the health and comfort of the people!

What if our government, states, municipalities would adopt EnerPHit? What if our architects, developers and contractors would adopt the Passive House Standard and it would be the way they design, build and retrofit buildings – every single one?

For me that is the goal. The Passive House Standard should be the way we build, period!

There is no alternative to Passive House.

My Own Foray Into EnerPHit

Using the EnerPHit toolbox , I created a master plan and first step for an EnerPHit step-by-step retrofit of a 1948 ranch style residential building.

Multiple renovation steps have already occurred in the past without any deep energy efficient measures in mind. Only the energy measures required by the building code had been applied.

The goal is to transform this house into a nearly zero energy home that provides high comfort all year around without any, or very minimal heating and cooling and a small amount of solar panels to energize the electrified home and two electric cars.

I am using EnerPHit to get there, cost effectively. Here is a picture book summarizing my first EnerPHit step, The Ranch EnerPHit Project.

In the meantime, check out this article about the brownstone in Brooklyn that was retrofitted using the Passive House Standard (albeit not step-by-step and from 2014).

Photo credits – All images related to EnerPHit in this blog post: Passive House Institute.

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