Tag Archives: green rehab

How do I start…

… with energy improvements on my home?

This is probably the question I get most often.

Whether you are thinking about smaller improvements or bigger ones, like our deep energy retrofit, here are some guidelines on how to go about it.

The big picture

It is not just about energy improvements, but it is also about where you get the biggest bang for your buck. So let’s take a look at the big picture.

For more data go to: https://www.eia.gov/consumption/

The 2015 chart above from the U.S. Energy Information Administration shows that up to 54% of energy for a single family home can go towards space conditioning (i.e. space heating and cooling). Only 5% of energy goes towards lighting.

If you decide to make your lighting more efficient, i.e. go with all Energy Star LED lighting, I applaud you. However, the total resulting energy savings may be around 1-2%. That’s something you may barely notice on your electrical bill.

If instead you would focus on improvements to your building envelope, i.e. your basement floor, foundation walls, crawlspace, exterior walls, wall penetrations, windows, exterior doors, attic, and roof, you could make a major dent in the 54% of energy that goes towards your space conditioning. This is where you can get a big bang for your buck. And not only that, you likely end up with a home that is a whole lot less drafty and a whole lot more comfortable and healthy to live in.

The bottom line is, don’t focus on the low hanging fruit. Look at the big picture and focus on the energy hogs, such as space conditioning.

Verify and quantify

You decided to not just chip away at your energy use but instead to make a dent, maybe even a really big dent.

Based on the data above, you know that you likely need to focus on your building envelope in order to reduce your space conditioning loads. But how good or bad is your building envelope, and what is the actual space conditioning load for your home?

It’s time to find out. Commission a home energy audit. A professional energy auditor will visit and inspect your home, analyze your utility bills, and may run several tests such as a duct, furnace, and blower door test.

For more information on home energy audits go to: https://www.energy.gov/energysaver/home-energy-audits/professional-home-energy-audits

The energy audit report will point you to the areas where energy improvements can be most effective. The most significant recommendations will probably point you to building envelope improvements, such as insulating, air sealing, door or window replacement, etc.

With this data and recommendations in hand, you can begin to strategize.


You have a choice. Even basic insulation along with good air sealing (also called home weatherization) can save you an “average of 15% on heating and cooling costs (or an average of 11% on total energy costs)” according to Energy Star information.

For more information go to: https://www.energy.gov/energysaver/weatherize/air-sealing-your-home

Depending on how handy you are, weatherization can become a DIY project or you can hire a weatherization specialist that does the air sealing and insulating for you. If you hire someone, make sure that you contractually set performance goals based on the home energy audit. This means how much more air tight the house should be after the improvements and what cold spots should be eliminated with insulation. And at the end, go and verify. In other words, have your energy auditor come back to test that the performance goals are met.

Energy model

You want to aim higher and save more? Good for you!

In this case I recommend commissioning an energy model, which your home energy auditor could provide. And if not, he or she can probably recommend someone. We commissioned an energy model in the planning phase of our project, which guided us through the decision making process.

An energy model takes a wide variety of building variables into account (type of windows, type of insulation, building exposure, air tightness, etc.) and predicts the energy load of your home. By adjusting the variables (i.e. thickness of insulation, type of windows, level of airtightness, etc.) you can see how the energy load of your home increases or decreases.

Say you want to decrease the energy load of your home by 50% or more, which puts you into the realm of deep energy retrofits. The energy model will help you to determine how to get there. It tells you what level of air tightness you need to achieve. It tells you what levels of insulation values you need, and where. It tells you what performance targets your windows and exterior doors should meet. And so on.

Decreasing your energy by 50% or more will involve major remodeling as you probably have to work on all exterior walls and the roof from the inside, the outside, or both.

Sounds daunting? Well, it can be. But there are silver linings here too.

Major remodeling allows you to get to all those quick fixes and deferred maintenance items that have been causing problems and eating money for years. And of course, you are left with major energy savings.

Take our deep energy retrofit. A preliminary analysis in 2016 showed a 80% reduction in our heating needs, and 57% reduction in our electrical use in 2012.

Be picky with your contractors

You will need help from various building trades with a deep energy retrofit. I highly recommend relying on contractors that specialize in energy improvements, or that are at least familiar with the topic. Working on energy improvements, such as in a deep energy retrofit, takes a very different mind set compared to regular construction, as the installation and construction processes often vary from the old norm. A recipe for disaster is a contractor that is set in the old ways, because that is how he/she has always done it.

Don’t tiptoe

Aiming high, such as with a deep energy retrofit, may seem expensive and overwhelming. You may think you should start in small increments instead.

Please think again.

Going about your improvements incrementally, each step in the process seems less overwhelming and less expensive. I’ll give you that. However you keep tiptoeing around big ticket items and associated savings (such as the above mentioned space conditioning). And you will likely end up undoing some of your own work along the process.

In the end, you may have spent cumulatively more on incremental improvements than on a deep energy retrofit with far less energy savings than you would have had if you didn’t tiptoe..

Learn how to operate your home

Owning a home, energy efficient or not, requires you to know how to operate it.

It is similar to owning a car: If you want to drive, you need to know how to start your car, how to steer it, how to accelerate and brake. You need to know what kind of gas you need, how to put gas in the tank, check tire pressure, check oil levels, etc.

The same is true for a home, in particular if you like to maximize your energy savings. You need to know when to change or clean which filters and when to schedule service appointments for what equipment. You will have to program and monitor your thermostat and other monitoring equipment. You should become familiar with the basics of indoor air quality (IAQ) and learn the basics about moisture management.

Owning a home is not a hands-off operation! There is no chauffeur. You need to drive if you intend to maximize your energy savings, assure the durability of your home and systems, and maintain a healthy and affordable living space.

Related posts:

On Air with Worldview

Just found your way to this blog? There is a good chance that you listened to Worldview 0n WBEZ with Jerome McDonnell and heard the segment about the deep energy retrofit of our 111-year-old masonry two flat.

The interview may have stoked your curiosity and interest. If so, can tour our building this Saturday (09/28) from 10:00 am till 4:00 pm. If you can’t make it or you have follow up questions on what you heard, this blog is the resource you want to use. To save you some time, I have composed a list of links that lead you to key posts.

This is where it starts – the building envelope

The best way to save energy is to effectively insulate and air seal the building envelope:

Electrical – saving watts

Now that the building is well insulated and air sealed, let’s take a closer look at how to bring our electricity consumption down:

Saving energy – hot water

And it’s not all about electricity. Bringing the hot water consumption down saves energy and ultimately dollars:

Staying warm

How do you stay warm during our Chicago winters? Here is what we did:

You still have questions? (and I bet you have)

Join us on Saturday, September 28th between 10:00 am and 4:00 pm to take a tour of our project.

The green smoke screen

Why this project – why this blog?

We had to answer those questions when we developed the idea of a deep energy retrofit. The articulation of project rationales served as a foundation for what was to come.

In those project rationales, I took a stab at new, green construction, voicing our frustration that it is often unaffordable for the masses and may qualify as “green”, but misses the point of sustainability.

It turns out that I am not the only one with some level of discontent on this subject matter – and that others, such as Martin Holladay at the GreenBuildingAdvisor.com, are beautifully no-nonsense in their expression of that discontent.

Read his blog post –

Musing of an Energy Nerd – Who Deserves the Prize for the Greenest Home in the U.S.?

– if you like to take a look behind the “green” smoke screen of the green building industry.

As to why this project – why this blog? Martin Holladay put his finger on what motivates us, probably without even knowing about what we are up to.

Breaking news on the insulation front

This is a very good day – for all those who own a masonry building, who are interested in a deep energy retrofit and who would like to insulate the masonry walls from the inside.

The frustration has been that there was next to no information available on the pros and cons of insulating the interior of masonry walls, or on how to go about it without damaging the structure.

The Building Science Corporation has taken another step to fill this information gap with the release of a brand new research report (RR-1105) “Internal Insulation of Masonry Walls: Final Measure Guideline,” authored by John Straube, Kohta Ueno and Christopher Schumacher.

Regular readers of the blog will remember my epic search for reliable and sound information on this subject. At the time, I came across one document – to repeat, one document – on this subject, also published by Building Science Corporation.

Do you really want to make an insulation decision of this magnitude based on one document? No, not really. But that’s all that was out there, in addition to some other documents that offered tangential information and the occasional anecdotal evidence.

We had to knit the little information we had together and hope that we got it right. I am glad to report that I see our decisions confirmed, after having read the executive summary of the new research report.

If you have done research yourself on the subject of deep energy retrofits and how to insulate, you will have noticed the abundance of information available for framed buildings or new construction. I cannot fathom why the existing masonry building stock, which is rather significant in metropolises like Chicago, is left without resources.

If we are to get serious about reducing our energy consumption and carbon footprint, we have to get serious about retrofitting the abundant existing masonry building stock. Building new and green can’t be the solution alone. We have to begin to reuse the resources we have.

I am glad that the Building Science Corporation is not shying away from this complex subject.

Plumbing installation – pipe size and fittings

At this point, and for quite a while, it is all about getting ready for the open cell foam insulation on the 1st floor.

Each unit is separated from the others by an air barrier – a two to three inch layer of open cell foam in the ceiling. There are a few tricky areas that represent a potential breach in the air barrier envelope.

One of the bigger potential breaches is the plumbing wall.

The plumbing wall is meant to be sealed between floors with spray foam insulation. That is once all the utilities (mainly plumbing) that run through it are installed. Half of the plumbing (the drain-waste-vent system) is in place. What is still missing is the fresh water or copper plumbing.

Plumbers usually know what to do with their eyes closed – as long as the project follows conventional construction practices. If you have read a few blog posts, you will have noticed that our green rehab project is miles away from being conventional.

To get over the road bump called green building technologies, I needed to be on my toes and communicate our goals and objectives frequently to my contractors.

Pipe sizes

The conventional wisdom is to have a large trunk line – one inch or at least three-quarter inch. The branches from the trunk line are typically sized three-quarter inch and run up to every fixture. Often the pipe is reduced to a half inch just prior to the fixture. These pipe sizes would assure sufficient flow rate to the fixtures and reduce the potential of undesired pressure drop.

For the sake of energy, material and water conservation we want the copper pipe size reduced as much as it is permitted by the Chicago Plumbing Code.

Pushing the code to its limits is rather counter intuitive for most plumbers, who are used to giving preference to the larger pipe sizes. Thinking and approaching the installation in terms of energy, material and water conservation did seem to take some effort.

Long sweep elbows

Pressure drop is an issue not to be ignored when going with the smallest permitted (or reasonable) pipe sizes. To reduce friction and turbulence in the piping, we have to leave the common and inexpensive 90 degree hard turn elbows behind and switch to the less common and more expensive 90 degree long sweep elbows.

Another option is to use 45 degree elbows where it makes sense.

The long sweep elbows are typically used in hydronic heating systems, not so much in fresh water plumbing. It was thus a good idea (and necessary) to check that no hard turn elbow found its way into the plumbing by accident.