A few months back, a Wallyhood reader had commented on the use of single-paned windows versus double-paned for the sake of energy efficiency at Hamilton. I spoke with Michael Romero from Heery (the Hamilton construction manager) and he informed me that due to Landmark Commission guidelines regarding replacement windows, all of the original 1926 windows and panes were left intact, with the exception of those that were broken or cracked. Each window was taken down, tagged, and sent to a window renovation specialist in Ballard, where they were re-sashed and re-weighted, and new pulleys and vinyl weather strips were installed. Any kind of heat loss from these windows equals about 5% of the building’s total heating budget, unlike the original windows in some of the surrounding homes in the neighborhood, which can cause up to 30% in heat loss. Re-use of the existing windows rather than building new double-paned windows to match the landmark windows saves the District roughly $2 million.
Each classroom is individually climate-controlled by a main pressure heating and cooling system. CO2 monitors are also in each class so that if the levels rise, the air connection pumps in fresh air from the outside. This monitoring means that outside air will only have to be heated or cooled when classrooms are in use and the fresh air is needed. Since most of the building’s heating budget is used for warming outside air required to keep air fresh in classrooms filled with students, this type of heating and cooling monitoring will reduce the building’s energy use by up to 20%.
While we’re on the subject of energy, here’s a recap of the construction work in progress:
At the end of January, all four main stairs were put into place, as were all windows in the main building and the addition. Finish work, including final drywall, paint, ceiling tiles, wood trim and ceramic tile, continues on the 3rd and 2nd floor of the historic building. The ADA ramp installation at the corners adjacent to the project is underway and sidewalks are now in place on the south side of the site and underway on the west side. All work on the Seattle City Light transformer was put in place, and the building was ready to have its electrical power turned on. Plaster restoration work began at the 2nd floor of the landmark spaces.
In February, the building’s electrical power was turned on. The contractor completed the rolled metal roofing at the new addition and new gym lobby. Painting of the new gym interior work on the floor coverings. Work will continue on the school/park interface, including the installation of the final stairs and completion of the retaining wall.
Aerial View of Hamilton International Middle School looking south, showing the new gym construction and the renovations of the historic building, taken January 19th, 2009. Aerial photos courtesy of Fred Cavazos, Above the Rest Blimp Photography http://www.atrphoto.com/
PHOTO CAPTION: Aerial View of Hamilton International Middle School looking south, showing the new gym construction and the renovations of the historic building, taken January 19th, 2009.
Aerial photos courtesy of Fred Cavazos, Above the Rest Blimp Photography http://www.atrphoto.com/
Beware of Greenwashing!
Discussing energy savings as a percentage of total energy is just plain silly. For example, take two buildings with identical windows and identical window areas, but have one building be an energy hog (perhaps because it is leaky) and the other be tight and energy-efficient. The heat loss through the glazing is the same in both buildings so the payback for the windows due to the energy savings is identical for both buildings. If the energy savings would pay for new windows in the efficient building, it will also pay for new windows in the energy hog!
It is the absolute quantity of energy saved that determines whether an improvement makes economic sense, not the percentage. The District will buy the same amount of energy forever to make up for the heat loss through the windows regardless of the percentage of the total. Would you pass up saving $20,000 per year in energy just because it was “only” 5% of your energy cost? Saving $20,000 per year is saving $20,000 per year, regardless of percent.
Further, the School District would have also saved on the size of the heating and cooling equipment in each space, the electrical service, the wiring, the water piping (the unit use water as the heating/cooling source), pumps, boilers and cooling towers. Energy savings ripple through every system in the building when you are replacing all of the systems anyway. And don’t forget the improved comfort and reduced fading that new windows offer. What a lost opportunity!
By the way, the Landmarks Board did not tell the School District they could not replace the old single-pane windows with new energy efficient windows. The School District never asked.
Funny, the cost for new windows touted during design and bid was $1 million. Even at that cost, replacement made economic sense. Perhaps that is why they are now saying new windows would have cost $2 million.
I was shocked – shocked – when I learned last year that Hamilton was going to be “remodeled” with single-pane windows. Who would ever do that in a their own house remodel? Was it the sort of fuzzy logic described above that persuaded the decision makers to accept the single-pane windows? Stunning.
By the way, what is the status on solar panels for Hamilton?
They didn’t replace the windows with single pane, they had the original 1926 ones cleaned and restored. If you read the city’s database of existing and proposed historic sites, this is actually a major consideration with historic buildings. So whether or not they asked the city for permission to swap them out, imho they acted responsibly in preserving an old building on the historic registry.
I for one will never replace my leaded single pane windows from the turn of the century. They add a character to the house that can’t be obtained with newer windows (and believe me I’ve looked.). Our climate is also temperate enough that in my experience,it’s not a huge deal for heat loss, especially when you have an efficient, updated heating and cooling system like a heat pump.
Also, since the 5% loss here is equal to 20k/yr in energy, It would take 50 years of savings to break even on the $1m cost of new windows, right? I am guessing the building will undergo another remodel by 2060.
And lastly, I was wondering how much energy does it take to make a million dollars worth of double pane windows you don’t need?
Greg make an excellent point. The addition of efficient window reduces the load on the mechanical system. Shouldn’t a fair accounting of window costs (an obvious moving target) include the reduced costs of a smaller mechanical system and likely less installation costs.
I followed the project during the design and permitting phase and attended many of the Landmarks Commission meetings. Keeping the old inefficient windows is not a Landmarks requirement. The renovation at Roosevelt HS provided new double pane windows in a Landmark building.
If the districts current logic is that thermally efficient windows only contributes to a small percentage of the overall efficiency of the building envelope, then why are the windows in the new portion of the building all double pane…..I was just starting to believe they are a waste of money.
While on the issue of costs. The construction update shows the installation of terrazzo floors, and what appears to be a custom inlaid floor medallion. As the district is asking the community for added tax levies, does it make sense that the floors in new buildings are custom terrazzo? Even within the context of this one building, I don’t see how custom terrazzo floors and inability to afford efficient windows are on the same spread sheet.
Also, it is hard to miss that the power has been switched on to the building. The second floor lights are left on all night. You can see the school like a lantern from the Aurora bridge at night. There is no work happening in the building at night. I’ll make the comment that this is not energy efficient. I suppose now the greenwashing crew at the school district will response that the new wires require current to flow through them for a certain amount of time for the lighting to run most effectively. I’ll wait for that in the next update.
I am curious about the negative responses from Greg and Bill… do you have kids that will attend Hamilton? I’m guessing not and am fairly certain that you did not support the remodel of this building from the get go. It’s really not about the windows for you is it? I really hope that you learn to embrace this beautiful new building and are able to take advantage of what it offers to our neighborhood.
I have two children who will both attend this fabulous new building and am very excited about the improvements that are being made. The old Hamilton was a dungeon and drastically needed updates. Having a building that is physically attractive will make a difference in the academic quality of the the school. It seems very shallow, but a pretty building will be more sought after by parents and teachers.
It is very exciting to be part of this new era for Hamilton. I hope the nay sayers can learn to appreciate this.
For citizens to step in and keep an eye on your levy dollars at work is simple good citizenship. The Seattle School District lacks oversight, something the new Mayor pointed out in his campaign. An elected School Board is almost always in flux with a new election looming, the Superintendent is appointed and there have been several in recent memory, and the District’s building department – “Facilities” – just keeps on installing fancy floors and tired windows and creating cost overruns. Be all for schools, we all are seems like, but also be for accountability and remember that Wallingford Playfield is our park, not an extension of the petite new Hamilton footprint.
Mom,
You guessed wrong. I also have two kids that will attend Hamilton. One will be in the first new class of 6th graders to attend. It will be a great facility, and my kids will benefit from that. Maybe here is where you are right, there are plenty of folks that are shallow enough to overlook;
Energy efficiency…..sure it is great to talk about….but do we really have what it takes to require our public buildings to be more sustainable.
Cost control…..really terazzo floors and custom fabricated curved metal roofing over windows.
School Inequality…..I’m sure the south end would love the attention the north end schools are receiving.
I did support a remodel. I supported a community response remodel plan that was based on school needs and the community input. A plan that even school board members said was a better plan, but the district staff said was “too late”. I volunteered time to work on that plan. I volunteered to be a member of the City of Seattle Department of Planning and Development Departures Committee that reviewed the district plan and provided community response. I wanted Hamilton to be the best plan for the school and the community.
I will not guess your involvement, just say that I am not the average “nay sayer”. I will appreciate Hamilton, I just wish there was more of what we Wallingfordians appreciate; energy efficiency, equality, and fiscal responsibility.
Bill, imho, you are conflating remodeling and new construction considerations. They are course putting double-panes in the NEW portion of the building. If you are starting from scratch on new construction this of course makes the most sense. (In fact it would probably cost you more trying to source single pane windows or have them custom made from a supply and demand perspective.) But remodeling and new construction have very different considerations. In an OLD building, you are starting with most everything you need and must evaluate the cost of replacement. So unless the vendor was willing to sell the school the windows on a no interest, 20k per year 50 yr installment plan, it seems like this was the best decision to me.
I am also very skeptical you could have sized the mechanical system any differently if you had that 5% efficiency back given that most HVAC systems have variable speed fans, etc.
As for leaving the lights on at night, I don’t know if it’s more efficient to just leave them these kinds of lights on or not, but I do know this is a pretty common practice in construction to reduce the risk of material theft and vandalism.
I’m not going to bother to argue the costs of the aesthetic choices like the medallion and terrazzo floors. You euther care about these things or you don’t, and if you do, they hold proportionate weight with other building concerns.
I can only say that when I saw the pictures, I was warmed, thinking that this is going to be a building we can all be proud of, and gather in as a community, and a school our children will enjoy being in, whether they recognize the aesthetic impact or not. Instilling pride in your school from the get go is a preemptive strike on Broken Windows theory becoming practice.
Old windows are great to look at. I suspect, however, that if nearly 1/2 of the wall area of your home was single-glazed, you might have different thoughts about perhaps putting in storms or double-glazed units. Remember, Hamilton will now also be mechanically cooled for the first time in its history and single-glazing essentially DOUBLES the cooling load for each of the perimeter classrooms. Just imagine the sun on the east, west and south exposures with no overhangs.
As a homeowner, you make a fiscal choice to keep old windows. Perhaps you can afford the cost for the extra energy used. A public school is a public resource, however, and the District will always be a bit short on cash. Is Hamilton a public school or a museum being preserved?
The $20,000 energy savings mentioned in my post was for a hypothetical building, not Hamilton, intended to point out that it is absolute savings that counts, not a percentage. The calculations are actually much more complex, especially when you are gutting an old building completely and starting anew.
The District figure for new windows was $813,450. If one subtracts the cost spent to refurbish the old ones, it would have cost approximately $435,000 to get all new windows for the building. These numbers are from the District’s consultant during design.
The 30-year present value of the energy savings for the new windows is $408,693 (again from the consultant). What this means is that the net cost to the School District to replace all the windows would have been $26,037 total over 30 years – or, a simple payback cost of $868 a year. To replace all the windows!
Now deduct the capital savings of $240,000 due to the smaller capacity HVAC equipment that could have been installed, plus another $80,000 savings over the 19-year life of the equipment for replacement and repairs, and the estimated cost for installing new windows at Hamilton over 30-years was a SAVINGS of $294,827. That is, the District would essentially have been PAID $10,000 each year, for 30 years, for installing the new windows. $10,000 a year in their pocket!
Throw in the added benefit of improved comfort for the students, reduced glare and reduced fading from UV and the decision seems a slam-dunk… but District Facilities was in a hurry.
The issue is not that folks are “nay-sayers”. Some if us spent countless hours on getting Hamilton a new home since 1996. No one is against Hamilton. There is nothing negative about watching out for what appear to be dumb decisions about public resources. After all, WE are the Owners. We are the ones who will be paying for these choices being made… for a long, long time.
Also, as someone with 32 years experience in HVAC design and energy analysis, it is uncomfortable to hear Greenwashing claims repeated that somehow the amount of energy saved does not matter. It does. If we are serious about sustainable design, better fiscal choices need to be made. Being in a hurry is no excuse for bad design choices.
Thanks Greg. Agree the calculations are incredibly complex. We’re likely all dramatically oversimplifying this.
About the numbers you present, are you saying it cost $380k to dip/strip the existing windows, and restore them at the specialist in Ballard? (Because you can’t count the cost of taking them out or reinstalling them. You would have had to do that labor even if you put in new windows.) I suspect that invoice is public-record, we could check.
Also, why do you account for these choices as the result of being in a hurry? Seems it would be much faster to yank the old windows and put in pre-hung new ones than to send the old ones out to be fixed. Seems like there may be more to this than we’re considering here.
Also, would the student’s comfort really be any different? I mean the system is definitely working harder on the perimeter rooms with single pane, I’ll give you that, but with constant air circulation and independent climate control in each room it seems like the temperature fluctuation wouldn’t be noticeable regardless of windows. (BTW Can’t you apply anti-glare/UV film coatings to single pane?)
Lastly, I was wondering why you used hypothetical figures before when you had these strong numbers to make your case from the beginning?
Howdy
The labor to remove and replace the windows would be essentially equal for both alternatives, so labor cancels out. During the design process, the rationale given by District Facilities again and again, was that they just did not have time to modify the design, no matter what was suggested. Ironically, waiting would have helped out financially because the recession kicked in after the District bid the job and bids on public projects plummeted 20% shortly thereafter. Instead, District Facilities rushed to bid the project on 90% completed design docs.
If the windows were replaced, the heating and cooling loads and equipment selection should be recalculated because properly sized equipment runs more efficiently and would be less expensive, so more savings, but it takes time to run the calcs again.
I’m getting a bit wonky, but human comfort is driven by both radiant heat loss and the convective/conductive heat loss. The latter is a first-power function of the room air temperature, but radiant heat loss is a fourth-power function of the line-of-sight transmission between two objects. This is why cars get frost on them more often on a cold clear night than a cold cloudy one – the car is radiating heat to deep space instead of to the “warmer” clouds. Fires keep you warm by radiant heat. A room can have the same air temperature, but the radiant heat loss through single pane glazing is substantially higher than low-e double pane. One simply feels colder in a room with a lot of glass, regardless of air temperature. This is primarily due to radiant heat loss and is one reason why you feel much warmer when you pull the drapes closed.
I asked Michael about low-e films during the design process, but the problem is that films are subject to damage and not likely a good choice in a rough environment like a public school. Carve your initials in the school windows, anyone 🙂
I used the hypothetical numbers only because I was too lazy to pull out my files from design. My recollection of the energy savings was not far off, though.
Again, this is not criticism of Hamilton, just of some of the choices made by District Facilities that often seem to be made on impulse and justified later. The justification given in the article for the windows is simply not correct. We should all chime in and call the Powers-that-be on it whenever that happens.
Interesting discussion. I have a few silly comments.
Chris, I have walked past that construction site a few times and they seem to have a fence around the entire site, also they have had a guard there with an idling call at night….not sure if that is still true, seems it would be hard to break in. Even though….re the lights a deterrent? Are there “kinds of lights” that are more efficient to leave in all night, news to me. Do they get to leave them on through summer break also?
….and Greg…yeah. comfort is comfort…who cares how long the furnace has to run! Yikes!
Greg, thanks for the only real data in this discussion.
Greg, thanks for the tremendous detail. Wonky is good. 🙂
Chuck, Poor form. I simply stated a fact about construction site safety/security practices, but thanks for the snark downplayed as “silliness” to give you an out. Greg’s most specific and helpful data came after the questions/challenges made in the discourse along the way, and he didn’t get upset when myself and others asked these questions in the form of assertions, he just graciously answered.
But yet you see fit to jump in at the end, incorrectly interpret my question, about how comfort quality can vary, as a statement and then mock it with a wink like you yourself share Greg’s expertise. Yikes, indeed!