We met briefly with the HO manager and they have a 3 story with parking garage under the 3 floors that is heated.  The building has 2 entrances with meeting area in both foyers and the foyers are open all the way to top of building.

The HO manager says they have about $50,000 allocated for some upgrades and he wants to know if I as an energy auditor can give the 70 owners any suggestions to improve the comfort issues in this 50 yr old building.  We are thinking about doing a sample of some units to see what issues we find with blower door and thermal.  

Making some suggestions as a start.  They have all electric heat furnaces in each unit with AC roof tops. We know there is poured concrete between floors and older aluminum framed windows at this point.

Does anyone have any thoughts or suggestions on how to approach this project.  

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Where is this project located?

Try getting an energy modeler to perform an analysis of the building.

In California, we work on Multifamily projects and the California Building Code for Energy Compliance requires the use of the California Simulation Engine, either CBECC-RES or EnergyPro software to perform this type of analysis. There is a report called an ECON-2 report that can show your building's energy consumption as-is, then will allow you to explore various upgrades, showing the cost and the energy savings benefit for each measure.

Windows should be the last thing to upgrade in my opinion, unless the energy model shows that they would be the greatest benefit. With your budget, you might be interested in other strategies such as window overhangs, better insulation, etc. and focus on basic thermal comfort to help mitigate long term climate change- depending on what you think the largest issues are for the building.

He is in the Chicago market & here single pane aluminum windows are not something you would like to have when the temps drop into the negatives much less electric heat... There are numerous was to look into this but I would start with the easiest - poll the existing tenants, look at utility numbers & then maybe do some testing / modeling to verify / quantify issues & ideas

If you are not part of Illinois Green Alliance you may look into it as many do a lot of similar items in Chicago itself 

With less than $1,000 / unit and comfort as the primary driver, air-sealing and select insulation seems likely to be the best solution.

But it's worth also looking at what the replacement schedule is for the AC and furnaces. If it's coming up soon, and depending on unit lay-out, etc. it might be worth replacing all heating and cooling with ductless minisplits on top of the air-sealing and insulation improvements (which would be a must to make this work well) and looking at the longer term financial savings and other benefits. 

With such a limited budget, you might focus on one of the biggest issues I’ve found in multiple dwellings: pressure differences.  Hard to make more specific suggestions without knowing more about the construction and layout, but I would look at the following:

- Unit ventilation strategy: if exhaust only, is it continuous?  How many CFM?

- Supply air: is it only to common halls and entrance areas? If so, is incoming supply conditioned?

The combination of apt exhaust only with common hall ventilation often causes a high negative pressure inside the apts, exacerbating infiltration of cold air and causing apt heating units to run overtime to keep up with the air changes.  In addition, the likelihood of the garage being effectively air sealed from the upper floors is zero.  And of course the stack effect pressure issues in the full height foyers.

I bet if you can find and fix some of the pressure issues, people will be a lot more comfortable, and save money too. 

Install ThermoDrain - drain water heat recovery technology onto the main drain stacks. Would need more info on location and type of water heating as well as drainage. Essentially the cost of one ThermoDrain would be shared by several dwellings and reduce the ROI substantially. 

Specification sheets uploaded


Interview a few home owners, get an understanding of their complaints and how important they are.

Budget may grow if you find enough pain.

Maybe the 50k should go towards diagnostics and design. At some point old equipment will need replacement, having a design spec in advance is really valuable.

Straight across should be replaced with ashp at minimum.

Agreed. Sample a few units. 

Use the GreenHome Inspection checklist https://greenhomeinstitute.org/greenstar-remodeling-inspection-chec...

Then work up some draft HERS ratings of some different units on each floor. Corner, center and etc. 

From there, try to find them some more money too! 

50K is not much to work with. I would look to air seal units. It will also improve sound and smell transfer between units.

2nd I would look to HVAC for comfort. HVAC and Air sealing usually solve many comfort issues. Is the HVAC system ducted? if so look to seal it up.  I would research AeroSealing and Aero Barrier. I know the Midwest Aero Barrier guys do good work. 

3rd if windows are leaky try to address that.

Good luck!


I agree that with the limited budget per unit it will be tough to really start tearing into things.  Sorry for the shameless plug, but depending on window square footage and current conditions, Indow window inserts might be a great option to improve comfort in each of the units.  There may not be enough budget to do all the windows, but since the install simply from the inside you could target comfort improvements specifically.  

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Large multi-families are challenging, both to test and to upgrade. I work solely in the single family/duplex market but From what I've seen at conferences and on line, the things I'd look for are:

Any concrete that can potentially act as a radiator to the exterior (cantilevers, edges of the floor system)

Interstitial connections between floors/units (even if the building shell is tight). Less likely with poured concrete floors as opposed to open web trusses, but still could happen at  penetrations that link up to (next):

Large openings in the building such as elevator shafts, mechanicals and flue chaseways.

You can work on individual units to make them more efficient but the effect will be diminished if the building as a whole isn't working.

For HVAC, definitely look into mini-split systems. A lot of hotel/motels are going to these so I'm sure those big chains are doing their due-diligence on the cost effectiveness of these systems.

With a small portion of the budget do an energy report as Jenna suggested, it should only be a few thousand dollars for energypro or CBEC analysis. The Econ II will list the energy savings by type of improvement. The majority of your savings will be in the exterior shell. Insulation and air sealing will be the biggest bang for your buck. Check to see if there are any local weatherization programs that may help with insulation and weatherproofing. They may do it for free depending on the tenants or owners income base. I am not sure if the 45L tax credit is still available for 2019 but you may be able to get a $2,000/unit tax credit if it is.

We do quite a few of these in California and Kansas, you can normally make a significant dent in the utility budget and comfort level of the units by concentrating on the shell.

We did a 1955 apt building.  budget started at $35K and ended at $234K.

A) show value,  cost of repair vs new, energy cost, system eff,  Cost per hr before - after ect

B) Pay back - short is not the big thing its rate of return

C) Cost to replace renters vs staying for 15 yr

D) Higher rent vs owner paying for all power needs

E)   worth of building to start vs final repairs

F)  The biggest thing was renters got to help plan and pay for total and then would brag about total.


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