Yesterday I received the final report from Zero Energy Design with the results of their energy modeling. We put out a joint press release this morning but I thought I would include a bit more detail along with some of the pretty charts that ZED made here on the blog.

Overview

ZED provided charts and analysis on three different models for the home. The first is the “Baseline” which is how a home built to code of the same size would perform. The next series is called “ZED Improved” and represents the features we plan to put in the base 100K House that will fit in our budget. The final model is called “ZED Optimized” and includes two optional upgrades that the home buyer could choose to have us install at an extra cost prior to them taking ownership of the home.

Before getting into more detail, here are two summary charts that show the results of the modeling.

The ZED Improved version that we will be going with on the base home will use 43% less energy than the Baseline code home. Zero Energy Design also remarked that the average existing home performs over 30% worse than a new code home built today. This means that the base 100K House should be 2.5 times more energy efficient that the average existing home.

The ZED Optimized version uses 8% less energy than the ZED Improved and 48% less than the Baseline model.

Three Model Comparison

Baseline Code Built Model

There’s not a lot to say about the Baseline model. Code homes have insulation values of R-13 in the walls and R-38 in the ceiling. They use standard windows, HVAC equipment and appliances that are not energy star rated. Below is the breakdown of monthly energy consumption by use. Heating is in red, lighting in yellow, hot water in orange and appliances in green.

ZED Improved Model (Base 100K House)

Some of the features that the ZED Improved model include are as follows:

• SIP walls at R-24, SIP ceilings at R-42 and a tighter envelope than code
• Energy Star windows by Pella Proline with a U-value of 0.34 and Solar Heat Gain Coefficient of 0.28
• Programmable Thermostat
• A 90% efficient gas water heater
• An Energy Recovery Ventilator (ERV)
• A solar thermal system with an 80-gallon tank and one solar panel
• Compact Fluorescent Lighting
• Energy Star Appliances

I have included a few more charts to show the performance breakdown for this model in a bit more detail below:

One thing to note is that as the home gets more energy efficient overall, the appliances really take up a large portion of the overall energy consumption. This is even without our TV’s, stereos and PC’s in the mix so you can start to see how much energy we still consume outside of heating and cooling. No matter how efficient a home is, it will still take a sizable renewable energy source like solar or wind to bring a home down to zero energy/carbon levels.

ZED Optimized Model

The ZED Optimized model adds two upgrade options to the home:

1. An additional solar thermal panel to double the impact on the hot water energy consumption
2. Cellular thermal window shades on all windows to double their R-value

We put these into the optimized model because they just could not be fit into the budget of the base 100K House. There is an outside chance that we can fit the second solar thermal panel into the budget due to federal incentives, but we will leave the window shades out. The buyer can decide if they would like to implement and also be able to choose the style and level of insulation they would like to have installed. See the final chart below for details on the Optimized model.

That’s it for now. I am off to a budget review meeting. We’ll try to provide more details on the equipment we decide to put in the final house over the next week as we nail this down with our HVAC installer and the rest of the team.

May from ISA passed on a link to a site where a couple is blogging about their process of designing and building a SIP/Modular Hybrid home. The site is www.GouinGreen.com and is meant to be a play on “Goin’ Green” as the couple’s last name is Gouin.

The couple has gone through a very similar process as we have here at 100K but they have the added complexity of coordinating the home to be built by a modular construction company using SIPs from a Pennsylvania vendor. Their home is being placed in Massachusetts and some of the features are as follows:

• ~3,000 sf
• R40 Poly SIPs
• Alpen high performance windows
• Geothermal Ground Source Heat Pump HVAC
• Ultimate Air 200 DX ERV (Same as we will most likely use)
• HERS rating of ~40 prior to renewable installations

These are just some of the features. The couple is now trying to get their building permits complete. Check out their site for more info. I have exchanged a few emails with them and they’re nice people. They have also been added to our blogroll.

We officially decided to go with the Pella Proline aluminum-clad wood casement windows for the 100K House project. The discussion that was sparked in the recent post on thermal shades was the clincher for us.

The Pella offering offered the best balance of modern style, quality, economy and energy efficiency for the home. The higher end brands as far as energy efficiency were just to far out of our budget to be considered in the end. The lower end offerings such as vinyl were also not at all appealing to us from both a green and design perspective.

Pella offers a nice look with aluminum cladding on the exterior in a nice range of modern colors and wooden interiors. The energy performance is good with U values of 0.34 for the operable versions and 0.29 for the fixed versions. We will actually have a number of fixed units in the homes, so the average U value will be around 0.32 for the home. The sliding doors from Pella that we selected also have a U value of 0.33 which is better than I expected.

I searched for a good image to show of the windows but just couldn’t find one of the specific model and style that we are going with. Most of the images show a more traditional window with grilles in between the panes. In case anyone is interested in the full details on Pella’s Proline windows, follow this link to their architectural design manual.

It’s been some time since I posted an inspirational project here. Last week, David Buege from Rural Studio contacted me about some $20K Houses they had been building for the past few years, so I thought I’d take the time to showcase them here.

Rural Studio is a remote program of the School of Architecture at Auburn University in west Alabama. For the past few years, their students have been designing and building low-income housing for only $20K in materials and labor ($10K ea). There is a Rural Development loan available through the federal government where very low income people in rural areas are able to borrow a maximum of $20,000 for home repair or construction.

The Rural Studio embarks on many projects each year, but the 20K House project was started in order to create a precedent that homes could be built on this extremely low budget that would outlast and outperform substandard housing or trailers that many in this very low income bracket are living in. This is extremely inspirational and really puts things in perspective for our project and others like it. I hope to visit David and his crew sometime in the future to see the work they have done in person. Check out their site and blogs for much more info and images, including interiors.

For more inspirational posts from the past, check out our inspiration category.

It’s the weekend so I get to spend some time on my long list of desired upgrades for the blog here at 100K House. This morning I added a new Archives page to the site. I must give Mr Chis Pearson credit for this upgrade. His blogging ideas are so simple, but so brilliant.

The new archives page lists the archives in three formats - by month, by category and individual posts. My favorite is this last method that lists ever single post ever written in one giant list from newest to oldest. It’s a great way to quickly scan old post titles to see if there is anything interesting that you might want to read. Lastly, I’ve also changed the format of the archive pages so that you see only a short excerpt of each post instead of the entire post. This lets you quickly scan through the month and category pages much faster to see all of the posts available.

If you’re new to the blog, check out the archives when you have a minute to see if there are any past posts that catch your eye.

It’s official, Postgreen and Level 5 Construction have teamed up to form a new construction company in Philadelphia - Build It Green. A few of you noticed that I changed the link in the left column from Level 5 to Build It Green and wandered over to the new site in the past few days. For the rest of you, head on over and check it out. The official press release on the site is linked below. Leave a comment for us over there if so inclined to help our launch day get off to a good start.

“Build It Green” is Formed as One of Philadelphia’s Only Custom Green Builders - May 2,2008

This is what has been keeping me busy over the past few weeks that I hinted to earlier. Building an entire new site has effected our posting lately, but we’re making a comeback now.

Scott and Donna Yohe, the founders of Level 5 Construction, approached me about a month or two ago to help revamp their existing website for L5C. I agreed and before I knew it, they had formed a new company to specialize in green building projects and wanted me to be a part of it. How could I say no? I couldn’t be happier with the turn in events and am very much looking forward to trying to grow the green building movement in Philadelphia in a much larger capacity than is possible through Postgreen.

Scott and Donna are the most professional builders I have met in Philadelphia and are really excited about getting involved in more green building projects like the 100K House project. We are working on putting together our first few green building projects that will immediately follow the 100K House project and will start meeting with new prospects and potential partners next week.

Again, if you have a minute, check out the new site and leave a comment for us on the press release post - http://www.BuildItGreenPhilly.com

I thought I’d take a close look at these insulating window shades today that Zero Energy Design is referencing in their energy model. There are a lot of cellular shades that are made up of one, two or three layers of honeycomb fabric with air in between the cells that makes the shade act as an insulator. From what I found, most shades can increase the R-value of a window by anywhere from 2.0 to 4.8 depending on the number and size of the cells and the material used. This is pretty significant since most energy star, double pane, low-e windows still have an R value of around 3.0 or less.

The first thing I thought when I heard insulating window shades was whether or not they would be ugly in a modern interior. After seeing some, I don’t think they look too bad. Look how happy the people above are with their installed shades! The bottom line is that in the city most are going to install some type of window covering for privacy, so why not give them a nice white shade that is custom made for their windows and save them some cost and hassle?

Zero Energy recommended looking at both Bali and Hunter Douglas brand shades. Long story short, Hunter seems to have the slightly better brand in terms of quality and R-values in their shades. They also offer one of the only triple-cell shades I could find.

There are a whole bunch of window shade sites out there but most of their pricing seems to be the same. I’ll use blinds.com for reference here as they seem to be a larger site. I priced a double cell shade in white that is semi-opaque to still let in light and for our 2′ x 5.5′ windows, they will cost $90 each. This has an R-value near 4.35 and the jump in price for the triple cell version is over $50 for only 0.45 increase in R value. Not really worth it in my opinion.

So we still have the question of whether this is a good investment toward improving the energy efficiency of the home. We will spend a little over $1,000 on the window shades which will decrease our energy costs by about $80 if the homeowner uses them properly and religiously year round. The other option is to spend more for the better Thermotech windows which guarantee a thermal improvement of almost $100 per year no matter how the homeowner uses them. The cost will be at least double the $1,000 premium for the better quality windows, but the labor costs will not increase. I would imagine the window shades will cost a couple hundred dollars to have installed in the overall budget.

What are your thoughts? Shades and the Pella windows or no shades with a superior Thermotech window?

Source Link: Great link on window shading options to improve energy efficienty. If you really wanted to go nuts you could probably bring your windows to a similar R-value as your existing walls by installing cellular shades internally in your windows, installing a roman shade over the window and then adding some heavy drapes outside of that. http://www.theblindspot.biz/energy-efficiency.htm

Yesterday I had our second conference call with Zero Energy Design who is performing energy modeling analysis on the 100K House. Yes, they changed their name since our last meeting. They provided a list of suggested energy improvements to the home with accompanying savings that would be realized over a code built home per year. I uploaded the spreadsheet to our documents page and an image of it is also shown below.

Note that the savings shown for each item is the estimated savings in one year of utility bills  over a  similar home built to code (IECC 2006). Each item does not take the other improvements into account, so ultimately the savings for each line item will be less in the final energy model that takes into account all improvements. Lastly, two versions of the model were run - one with A/C and one without.

The list yielded some interesting results as follows:

1. Beefing up the SIPs further was not recommended.  We currently have 6.5″ wall panels and 10.25″ ceiling panels spec’ed out and ZED recommended staying with the same wall panels and reducing the ceiling to 8.25″. The model only takes into account the R value of the different SIPs but I was surprised to see how little effect the higher levels of roof insulation would make.
2. There is a decent difference in the window types we are evaluating, but we will need to determine whether the significant cost premium for the Thermotech windows will pay off or if it is better spent somewhere else.
3. Insulating window shades seems to be a very good investment given the relatively low cost to essentially double the insulation value of the windows.
4. Window overhangs don’t have as much effect as I thought they would. The negative value with no A/C is because some sun will be blocked in the winter that would reduce the heating load while there is no reduction in A/C costs in the summer, because there is no A/C. This does not mean they will not be needed in the summer, as we need to cool the home as much as possible via passive methods.
5. An efficient boiler seems to be the way to go for heating both the domestic and radiant water. It even outperforms the popular tankless units being used today.
6. Amazing what a difference a simple $20 programmable thermostat can make!
7. Solar thermal is looking like a good investment, especially with the boiler and tank setup and the possibility of eliminating A/C.
8. CFL’s are more efficient that LEDs. Who knew? ZED says this is a common misconception due to the amount of LEDs that are needed to match the light output of CFLs in a similar spectrum of light that is pleasing to the eyes.

The next step is for ZED to plug the items we have chosen into their detailed energy model to determine the amount we can expect to save over a code built home. We did not get into specific models of equipment to be used too much in the meeting, but that will all be included in their final report. I can’t wait to see some pretty charts that clearly illustrate the predicted energy savings of the home. I will be posting in more detail on some of my thoughts on each of these line items also over the next few days.

This weekend I met with Mr. Matt Pappajohn of Pappajohn Woodworking to further discuss our “Urban Kitchen” design and possible materials. Matt has seen our renderings and has agreed that we can create a similar kitchen out of sustainable materials and green finishes that will fit in our budget for both homes. This makes me very happy and officially adds Pappajohn Woodworking to our team (they can now be found in the left column with the rest of the team members).

We talked about the various methods of constructing a cabinet that would be the most cost effective. Building cabinets with posts for legs like the Hansen Kitchens that I like so much is not as cost effective as traditional boxes with legs. Matt had some nice pieces of reclaimed wood from pickle barrels, old growth structural beams and flooring, but in the end we decided to go a more traditional route that could be easily replicated for others interested in a similar kitchen from Pappajohn.

I snapped a few pics of the desk that Matt and his brother Ian had built for their office made of Apple Plywood that became the inspiration for the basic design of our cabinets.


I’ve always liked this style of cabinetry with the plywood edge of the frame exposed. We started talking about a contrasting material for the door and drawer fronts. Matt has a couple of ideas which he is going to explore and we both really like the Neopolitan Plywood offered by Plyboo shown below. This could really look nice against the grain of the plywood.

We should be able to keep the entire kitchen off of the ground with some sturdy legs to get the furniture feel I’ve been craving. There are a lot of attractive legs commonly used for kitchens, but I think I may be leaning toward something a bit more industrial that you might find in a Grainger catalog to fit with our urban and functional theme.

Some other notes include adding a vertical support in the middle of the island to break up the six foot span and offer the support that will be needed. We may also install sliding shelves in the top half of the island and leave the bottom shelved fixed. The three large shelved shown along the wall in the rendering will also become drawers that will be 42″ wide. The top drawer will be shallow, allowing for silverware, while the other two drawers will be as deep as possible for maximum storage.

This is a big step for the kitchen design as I never thought we could afford a custom cabinet. I think the direction we are heading also will be very flexible for other customers. Pappajohn could offer quite a variety of different sustainable and reclaimed products that could substitute for the more affordable options we will lean towards. This could result in a nice line of semi-custom, modern & green cabinets…

You’ve all been patient with our decreased posting the past few weeks so ISA decided to reward you all with the first interior renderings of the home. I’ll save my thoughts for later an let you guys comment first. If you’ve always wanted to comment but never have, now’s your chance. Also, before someone mentions it, these are actually renderings of the 120K House that has some extra windows on the west wall.

Lastly, somehow I did not realize until recently that flickr provides RSS Feeds so I have just added our flickr image RSS feed to the left sidebar under the big RSS icon. I often post images well before including them in posts and also include inspirational images that never make it to the blog.