Showing posts with label energy efficiency. Show all posts
Showing posts with label energy efficiency. Show all posts

Monday, November 5, 2012

First year utility update

As we were preparing for our open house yesterday, we remembered how we were a little skeptical of the savings we would enjoy with a full ICF home. We knew that we would save money, but what we really wanted to see was hard numbers for an actual house, not percentages and averages.

We decided to pay it forward by offering our actual utility costs. Our house is 2,880 square feet (finished) = 1,700 in the unfinished basement.




We are amazed that we are paying much less than we did last year, in a house half the size of this one. Equally impressive is the fact that our actual costs will be nearly a thousand dollars less that the projected costs based on our low HERS score. 

The flyer with this information was very popular with the potential homeowners who toured our home this weekend. Several asked about the temperatures at which we kept our thermostat. 

In the summer, we often kept it between 76 and 78 degrees (F), not because we were trying to save more money, but because the house was quite cool and comfortable at that temperature. As a comparison, I was sweating at anything above 68 in our old house. 

In the winter, we kept the thermostat between 66 and 68, again, simply because that's where our home comfortable. In our old house, we kept it at 72 because I would be cold even while wearing warm clothes.

Another thing we didn't expect was how well the house holds the temperature. Yesterday, it was in the upper 30s. We had the thermostat at 68, but the house temperature went up to 70, with the furnace still off, just from all the people walking through. Last winter, we didn't turn on the heat until the temperature was 29 degrees outside, because the temp inside was still in the upper 60s!

We had a very hot summer this year, with several days in the 100s. Our electric bill in August was $150, nearly a hundred dollars less than we paid in our much smaller house a year earlier. 

One last thought: other than the first three months of the year, our gas bill has consistently been between $25 and $27 dollars. In January and February, the two coldest months of the year, our house was still under construction, and our March bill only reflected two weeks of occupancy (plus two weeks of workers going in and out all day). To compare, in our previous smaller house, we paid $168, $162, and $146 in January - March 2011. It's worth mentioning that our previous home was less than ten years old and fairly energy efficient as well, as we had a home energy audit before putting it on the market.

Saturday, April 21, 2012

LEED certification

One of the things we kind of brushed aside was the LEED certification of our house build. The main reason for that decision was the paperwork and additional project meetings that are required as part of the certification. In my opinion - and take it for what it's worth - the LEED certification needs to be focussed a little more on the actual product than on the process.

Don't get me wrong, LEED certification is an excellent guarantee that your home is truly green and sustainble but requires you to have an official kick-off meeting with a detailed project team and a complete action plan PRIOR to you build or you risk being ineligble to achieve a LEED for Homes certification. Your house may be the lowest HERS on the block, have renewable everything, but if you forgot to hold your meeting you cannot be certified (exceptions always possible...).

Regardless, I did a quick score on the LEED for Homes site and after answering the questions to the best of my abilities we came out half-way between a Silver and Gold.

Since our house actually has a HERS score of 38 , we used advanced framing (e.g. ICF), renewable materials (e.g. cork flooring), have virtually no air leakage, all CFL and LED lighting, all EnergyStar appliances (most even CEE II or III) and all WaterSense fixtures and sourced most material from within 500 miles we probably would have scored a solid 'LEED Gold'.

Brushing aside the LEED certification surely kicked way back on the paperwork (and probably the headaches as well) but as we kept the certification rules in the back of our mind in building decision-making the building result would have been almost 100% the same.

So, piece of advice: if you truly want a LEED certification for you building, make sure to get your ducks in a row prior to starting your build or risk not being able to get certified.

Tuesday, April 10, 2012

Home Energy Rating Certificate

On a couple of previous posts we've talked about the HERS rating index. It stands for Home Energy Rating Scale and measures the energy performance of your house. For many people it's just another bit of 'Green' mumbo-jumbo so let me try to explain why this number might actually start to mean something for the average American home buyer and home owner within the next couple of years...

Consider a car. We select it on a whole range of criteria and recently gas mileage has become an increasingly important factor. We still want big cars, but we still want it to be energy efficient and get good mileage. The index used for cars is MPG.

Think of the HERS rating index as the MPG number for your house. The only difference is that the HERS scale uses 0 as a value where no outside energy is consumed (house produces as much energy as it consumes) through solar panels, geo-thermal heating, wind turbines, etc... so a lower score is better where for cars a higher score is better.

The HERS scale goes from 500 down to 0 where each number represents a 1% difference. The average new house built to minimum code in the USA scores about 100 on the HERS scale and you reach Energy Star levels at 75 to 70 depending on which Energy Star version (2.5 or 3.0).

Our house scores a pretty impressive 38 on that scale. A quick browse around the web learns that there are precious few houses under 38, espcially not without the use of any renewable resouces. The 38 score means that our house is a whopping 62% more efficient than the average new American home that is build to minimum code.This translates in a pretty low monthly utility bills.

The score of 38 based on the overall scall... as you can see anything below 70 is basically 'off-the-charts'.

So far, especially our gas bills are way down. March was just $7.38 in usage charge (we used only 1.3 MCF). The March electric bill was $132 for a total utility bill of just under $160. Keep in mind that we have a lot of appliances in a large house (3000 sq.ft above ground, 1700 sq.ft basement + garage) leading to a conditioned area of a little over 50,000 cu.ft. For a house this size average total utility bills under $160 per month are pretty darn good. As a comparison, our previous house was build in 2003 and the average for that house was $180, but... for a house half the size...

In the future we'll probably be installing some solar panels on the back of our house, most of which has south-west exposure to catch the most intensive solar rays of the day. That will help bring down the electricity cost. But first we need our savings account to renew before we can invest in renewable resources...

That brings me back to my opening line...'why this number might actually start to mean something for the average American home buyer and home owner within the next couple of years'... There are some talks in the industry to add a HERS index to how mortgages and home appraisals are being calculated. A house with a low HERS index will be worth more since it's using less energy thus leading to lower monthly bills. That in-turn can be used in mortgage applications since disposable income in a lower HERS index house is higher than in a house with higerh HERS index.

Very curious to see where this is going, but if it does happen, we're ready for it...

Friday, April 6, 2012

Offical HERS Score came back...

Just got a call from our contractor about the official HERS score for our house. The preliminary score - based on the actual readings - was 41, but after all calculations were done the house actually came in 3% better.

Therefore, both Charis Homes and de Jong family are proud to present a HERS score of... 38!!


Our contractor was just as happy as it is their first house in the 30's. Keep in mind that the average new house is between 100 and 75 (with 0 being a net-zero house).

Note that this HERS score of 38 was achieved without the use of any renewable engery sources (geothermal, solar, wind). By adding solar in the future we can reduce this even further. As a comparison, it's the same score as the HGTV Green Home from last year but that house is using solar for a large part of their electricity need.

Having a HERS score in the 30s with just smart building and a properly constructed tight building envelop reduces the need of using energy. This is the first and - in our opinion - the most important step. After that it is time to see if or when you want to generate (a portion of) the remaining energy needs from renewable resources.

Thank you, Charis Homes for building us the engery-efficient house we wanted!

Dominion Gas Bill: March

For those of you bored with my project and organization posts, here's a fun one about the energy efficiency of our new house. We just received our bill for March, the first full month we've been in the house, heating it (not that it was needed much with such a mild winter), and using all the appliances.

First, the breakdown. I'm not sure why we are charged from both Dominion and Vectron, but they both chip in and ask for money.


DOMINION:
Basic Monthly Charge - $20.37
Usage Based Charges - $1.67
(1.3 MCF @ $1.3000)
Gross Receipts Tax - $1.02
Total Dominion Charges: $23.08


VECTRON:
Standard Choice Offer (SCO)
Gas Cost 1.3 MCF @ $3.446 - $4.48
Sales Tax - $.29
Total Vectron Charges: $4.77


Total Bill: $27.85


Yep, living the dream.
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