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“Top 10” Home Performance Renovations? What If You Had To Choose?

May 25th, 2010 categories: Energy Package, EnergyWise Education, EnergyWise Renovation, Green Renovation, Home Performance, Investors, RENOVATORS

That was exactly the question that one of the readers from Sacramento asked me last week.  I thought it was a good question and worthy of writing an article about.   But first the disclaimer and a few caveats.    Us humans love lists,  especially Top 10 lists.   They can be an aid to thinking, especially for the one who has to think them up … but they can also limit the thinking process if you just follow the 10 point recipe, without thinking why each of the Top 10 made the cut, and whether those same criteria are true in their own building.    So there’s danger for those who would like to shut down thinking and charge ahead with a list of ingredients for a cookie recipe.    On the other hand, it’s a wonderful exercise that everyone in Home Performance should consider on their own property. Check out 100119 The Energy Package

Criteria For Selection And A Little History

In the 1980’s Pacific Gas and Electric had a Weatherization Program that used the “Big 6.”   If I remember, it included Attic to R19, Caulking, Water Heater Wrap, Lo Flo Showerheads, Outlet Gaskets and some Pipe Wrap.     After a few years of looking at the results, it was decided that the Big 6 was having little impact on Home Performance and in many cases saved no energy at all.

Autopsy:  What’s went wrong with the Big 6?

Several factors can lead to disappointing results in energy saving plans.

1.  The items were included because they were easy to inspect.   They weren’t really the biggest opportunities avaialable at the time

2.  There was little customer education or buy-in.   Customers would replace the new showerhead with their old one because they liked it better.   The program finally had to start collecting and destroying the old models.

3.  There was no testing or thought about where to caulk.   Contractors knew only,  “get some caulk on the building and bill the program.”   Installers knew even less,  “the boss want some caulking, so give him some caulking.”   Some even got paid piecework so miles of lap siding got caulked…..   until that got stopped.

4.  In Sum,  It’s not bad to have 6 or 10 or 12 items to focus on.    The Big 6 were just the wrong 6 (except for the Attic,  and even that was wasted because it wasn’t preceded by a “shell seal.”

5.  With no testing or understanding of Building Science, any such prescriptive approach will include a fair amount of waste and provide minimal Home Performance.

But If I Had To Choose:

Home Performance can be broken into Two Basic Goals and Two Basic sets of Safety Questions.   If we break it up into systems, this is not rocket science.   The 2 goals are building a good envelope and providing a good comfort system.   The Safety Issues are Air Quality and Managing Water.

Before insulating the envelope, we must seal it.

1.  Shell seal the Attic.   The attic floor and knee walls and other BTU leakers

2.  Seal under any Raised Floor.  Shell sealing materials are the same as used in the attic.    Sealing the crawl space is an option here.

3.  Seal Thermal Bypasses and The Band Joists and other areas between the floor and ceiling.    This may be a little invasive,  perhaps removing some siding to gain access or drilling.  Sealing around new or existing windows.

4.  Seal the Ducts.  It’s almost always better to replace these and do it right than try to repair and seal existing ducts.   This is because even if you seal them, they will still be the wrong size, running to the wrong places, poorly insulated, dirty, and near the end of their lifespan (if they are flex) These should be tested to leak no more than 3% of the air going thru them.   If you think about it they are really part of the building envelope.   Just like the envelope is part of the plenum.   All leaks hurt building performance, and none more than duct leaks.

Stop and measure. With these 4 items addressed, it’s time to break out the blower door and duct blaster and run some tests. There’s no use adding insulation to a leaky envelope or leaky ducts.

5.  Attic Insulation.   After a tightly sealed attic floor, and addressing all heat producers you can proceed.     Getting Rid of  Recessed Lights or properly treating them for air tightness must be addressed at this point.  Plan your buildings to last 100 years.   Usually add about double what others are putting in.

6.  Wall Insulation.   If it hasn’t been done previously consider dense pack cellulose.     All knee walls need some help.    2 inches of FSK insulation usually covers it.    For deeper retrofits adding rigid foam to the outside walls can be a huge energy saver.

7.  Comfort System.   With Mini Split Heat Pumps producing SEER ratings up to 26 and able to heat down to near zero degrees, I am recommending them almost everywhere.  These should be tested to ensure that they are delivering the listed amount of BTU’s into the building.    No use paying for big claims and not getting delivered performance.

8.  Energy Efficient appliances and Lighting including Controls.

9.  Safety.   This of course includes Carbon Monoxide testing.   It can include other Air Quality testing such as Volatile Organic Compounds VOCs etc.   If our sealing efforts have been successful, we must Ventilate on Purpose with mechanical ventilation.  I recommend an Energy Recovery Ventilator or a Heat Recovery Ventilator for all jobs where the CFM50 rating is less than the floor area in square feet.

10.  Water.   This includes three aspects,  saving it, heating it, & keeping it out of our building.   Two stage toilets, water saving shower heads, low water landscaping plants and drip irrigation all address the saving issue.    Solar hot water, Heat Pump water heaters or condensing water heaters along with right sized PEX delivery systems and a simple heat recovery drain system are our tools of the trade for heating water efficiently.    Keeping water out may include grading to drain it away, french drains, & house wrap and a studious concern with the vapor barrier.

So there you have it.   A Top 10 list that would be appropriate for Home Performance in the “Average House”  (in my part of California)    Of course most houses aren’t average.  I’ve been told repeatedly that there are no average houses in Nevada City or Berkeley!    And in the Mixed Humid Climate of Virginia,where I’m going, things will will obviously change.     But because this list is based on Principles, rather than just a cook book,    they wont change that much.

Determining exactly how these 10 will be modified  on your particular building will make you think … and that’s a good thing!

I’d like to hear your version of a Top 10 list.    Post them in the Comments Section or over on the FaceBook Discussion Tab.

This entry was posted on Tuesday, May 25th, 2010 at 12:54 am and is filed under Energy Package, EnergyWise Education, EnergyWise Renovation, Green Renovation, Home Performance, Investors, RENOVATORS. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

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