Improving the Efficiency of Your Single-Family Home

Buying a home can be overwhelming. There are many factors that need to be considered and decisions that need to be made. For many Americans, aesthetics often outweigh certain characteristics critical to a home’s success, such as health, comfort, and efficiency.

To help us evaluate these critical characteristics, we’ve asked SWA’s COO and Mechanical Engineer, Srikanth Puttagunta, to walk us through his recent home-buying experience. Sri discusses ways to maximize a home’s value by taking advantage of incentives, enhancing existing infrastructure, and making the key decisions that may benefit your family’s health and comfort for years come. Join us as we dive into the essentials of single-family home ownership. 

Episode Guests: Srikanth Puttagunta

Srikanth Puttagunta HeadshotThrough his involvement with the Department of Energy’s Building America Research Program, Sri has an extensive background in barriers and challenges that residential builders and multifamily developers face to meet the requirements of codes and higher efficiency programs. He performs design reviews and building forensic investigations, identifies energy saving opportunities, quantifies the associated energy and cost savings, provides technical consulting, and supports measurement and verification of long-term energy savings. In addition, Sri has been involved in several of SWA’s product development efforts and also collaborates with industry partners on enhancements to their mechanical system product offerings.

Episode Information and Resources

Learn more about Sri’s home improvement projects in our Party Walls Blog!

Programs and Studies Discussed:

Federal Incentives:

Upcoming Events and Conferences

BuildingEnergy NYC, October 3-4

The BuildingEnergy NYC Conference + Trade Show is NYC’s premier event for professionals and practitioners in the fields of high-performance building, energy efficiency, and renewable energy. SWA will have various speakers presenting on an array of building energy topics. Come visit us! 

NAPHN Conference, October 17-21

Join North America’s Passive House community as it convenes in a surprising hotspot of Passive House design and construction: Pittsburgh, Pennsylvania. SWA has four sessions at the NAPHN conference on a variety of Passive House topics. Hope to see you there!

Upcoming Training

NAPHN’s Certified Passive House Designer or Consultant training

*Available in various locations across the nation and every other month in NYC!


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About Buildings and Beyond

Buildings and Beyond is a production of Steven Winter Associates. We provide energy, green building, and accessibility consulting services to improve the built environment. For more information, visit


Robb Aldrich | Kelly Westby

Production Team

Heather Breslin | Alex Mirabile | Dylan Martello

Next up on Buildings and Beyond…

Smart Buildings 

Guest: Dave Unger

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Episode Transcript

Kelly:                                  00:06                   welcome to buildings and beyond

Robb:                                00:09                   the podcast that explores how we can create a more sustainable built environment

Kelly:                                  00:13                   by focusing on efficiency, accessibility and health.

Robb:                                00:18                   I’m Robb Aldrich

Kelly:                                  00:19                   and I’m Kelly Westby

Robb:                                00:21                   and before we get into this week’s episode, we wanted to let you know about a couple of upcoming events. Dylan Martello, who is a passive house consultant here at SWA, and is really instrumental in putting this podcast together, helping to produce the podcast. He’s going to be speaking at both of these conferences and he’ll give you a little bit of Info about them.

Dylan:                                00:40                   Thanks Robb. The first is building energy NYC conference taking place on October 3rd and fourth in New York City. The conference which is presented by Northeast Sustainable Energy Association or NESEA, has become a staple for professionals and practitioners in the field of high performance building energy efficiency and renewable energy. We’ve been to the building energy conferences for many years now and my colleagues and I are looking forward to returning for another great event. Visit for more info.

Robb:                                01:09                   Yeah, I’ve been involved with NESEA for 20 years or so and they’re really good people and I’ve learned tons at NESEA conferences over the years.

Dylan:                                01:17                   Next is the North American Passive House Network Conference and expo taking place at the David l Lauren’s convention center in Pittsburgh, Pa. Join us October 17th through the 21st where we’ll be speaking on a variety of topics related to passive house visit for more info.

Robb:                                01:35                   Thanks Dylan.

Kelly:                                  01:37                   Are you interested in becoming a certified passive house designer or consultant? Checkout North American passive house network’s five day training in various locations across the nation and every other month in New York City. See Their website for an updated schedule.

Kelly:                                  01:54                   Welcome everyone. I’m very excited about today. It’s a little bit of an indulgence for me because I am actually working on some planning, some renovations for my own house. And so I have Sri Puttagunta on from Steven winter associates. He’s a mechanical engineer and focuses on residential home consulting. Mostly on the HVHC and mechanical side. He’s also done a lot of residential research initiatives for different programs, building America, and various other programs. And today we’re going to take a little bit of a personal tone and talk about renovations that he’s done on his own house. So let’s just jump right in.

Kelly:                                  02:37                   So Sri, thank you for being on the podcast. I wanted you to talk a little bit about a switch that you had made in your life. I let everybody know a little bit about your background in the built environment in the residential sector and you bought a house and turned the tables and now you are the client. So tell me a little bit about what that was like.

Sri:                                     03:04                   Yeah. A couple of years ago I was living in a townhouse and had to deal with condos issues and not really be able to touch much in my house, and decided to move out to the burbs. And we ended up purchasing a 1960 split level home. And while it had some nice updates in it from an aesthetic standpoint, it was your typical 1960s home in terms of everything that we love in terms of energy efficiency, and health. So it was an interesting process. One of the main things, was this was probably the first time we actually got into being the client. So everything I’ve done has always been on the consulting side and it’s easy to tell somebody what to do, especially when it’s not your money. But in this case it’s both being the client and the consultant. And of course I can see the bottom dollar. So it was really quite interesting in that aspect. And like every other project you have to sort of make your selections of what you want to do, what you might do later on and what you’re just going to have to skip for this project.

Kelly:                                  04:14                   Yeah. And I’d love to get into all of that, but first, do you want to give me a little basic overview of some of the things that you did in your renovations?

Sri:                                     04:26                   Sure. The house itself is right around 1600 square feet, it is as I’ve mentioned, a split level. And the main things we focused on originally was, the envelope. So first things where: it had essentially R4 degraded insulation in it. And we are looking at different ways to insulate that both in the walls and then also looking at the roof through the process of doing this. And one of the interesting thing is, we actually found that there was a very large pest infestation in the house. So mice, dead mice literally everywhere. Roof ceiling, basement, it was pretty bad. So We figured this is a perfect opportunity. We’ll do air sealing, we’ll do the installation, and we’ll be able to take care of the pest problem as well. So that was the main thing that we did.

Sri:                                     05:21                   We did dense packed cellulose into the exterior walls and then a close spell spray foam in the ceiling. So just because it was in most cases a pitched roof, vaulted ceiling, we wanted to get a high enough R value in the ceiling. And so we did add the roof deck itself. Some of the other things- the home was originally an oil boiler. And when we first were looking for house, I was absolutely against an oil house. I’d said no way. And when we put in the offer for the house, I was standing the street and there’s a gas line in the street and I called the utility company like, I don’t have gas, it’s on the street. And they said, no, you don’t have gas in your street. I was like, I’m literally standing on the valve.

Sri:                                     06:10                   And I took some while, but I finally got them to come out and they’re like, oh yeah, you have gas. And so we were able to get gas connected to the house. So we did some improvements in terms of the old existing boiler updating it to a tankless boiler. We kept the radiant baseboards. I didn’t feel like doing any traditional drywall work, so I said, hey, if we want to use it, we can have it. There were some through wall AC units in the house. But I was looking for something a little better than that. And again, part of trying to air seal through all units really don’t cut it. So we actually included a multipart air source heat pump in that house as well. Because it’s split level, we really didn’t have an opportunity to put duct work, so using the individual heads a lot is to get zoning as we wanted to meet our cooling needs.

Kelly:                                  07:04                   That’s awesome. And I think you told me a story that I thought was a really interesting anecdote about how you had called the people that used to live at your house and they had some issues with their children, they had asthma symptoms while they were in the house and when they left, they didn’t really have those symptoms anymore.

Sri:                                     07:23                   Yeah, when we started doing inspections and everything and we found all sort of issues with mice, there was feces everywhere. And so anywhere we were going, we were vacuuming everything up and that’s when I just, I’d had caught some information from the previous homeowners cause I was curious about their utility costs and stuff. So I had their information and I just sort of had an offhanded comment with them to talk about health. And I was just like, you know, it seems like there’s a lot of sort of pest issues in the house. Did your kids ever have any issues? And they had talked about the kids, which were in I think were five, seven years old. And they said, yeah, they were having a lot of asthma issues. And then I said, you know, I might understand why they’re having asthma issues. And they also just off handily mentioned that they sort of were reduced once they moved away. They moved into a new construction house, which didn’t have the same issues as their previous house. So it was definitely high on our list to take care of, as one of the priorities for any of the work we were doing

Kelly:                                  08:32                   for your own family. And you’d mentioned kind of in the beginning a little bit about challenges with budgeting. Do you want to talk about what specific examples you have that came up that were issues that you maybe didn’t predict in the beginning?

Sri:                                     08:47                   I mean, one of them, you always under budget, you think everything should be cheaper than it really is. Once you get into and you see all the details and you want to do a high quality job, it ends up taking more than you originally estimate. But one of the big things that I really wanted to originally do was adding exterior rigid insulation to the home. So I figured it’s two by four walls. If I dense packet, I’m getting into maybe R15, I can do a little better than that by putting an inch of rigid on exterior. So it made perfect sense. But once we pulled down the siding and we’re starting to look at it, we had done the dense pack of the cellulose from exterior actually. we didn’t want to actually take down any of the interior dry wall.

Sri:                                     09:29                   So we’re able to do most of it not being so intrusive to the interior of the home. But when doing that, we actually noticed the windows on half of the house we’re essentially retrofit windows that they installed at a later date. And the way they installed it was actually incorrect. And so we were actually having water that was draining back into the wall cavity. so wasn’t something we originally anticipating having to deal with in terms of cost. And so we ended up doing a tradeoff there of buying half house of new windows and eliminating the rigid insulation.

Kelly:                                  10:07                   Okay. Interesting. And did you find big issues? I mean, windows are obviously supposed to keep the water out, not funnel it into the wall cavity. So was there any major issues from that?

Sri:                                     10:18                   we were fortunate. I guess one of the things with old 1960 homes is that they’re very leaky, so if they get wet, they dry out pretty quickly. so there was some evidence of water damage, but the real extent of it was really just changing some couple pieces of plywood to the exterior. so there wasn’t anything drastic.

Kelly:                                  10:40                   But obviously the windows added a lot of costs?

Sri:                                     10:40                   Yeah. And especially with us insulating and tightening up the home, it would have been a serious issue moving forward if we would have left it the same way cause It wouldn’t have dried out.

Kelly:                                  10:53                   Right. And did you look at any monitoring? Do you know how much energy consumption was reduced by your retrofit?

Sri:                                     11:04                   Yeah. So because we’re energy Geeks, certainly I wanted to know sort of everything about it. So as I mentioned, we reached out to the previous homeowners to get their utility bills. so we actually got two years of their utility bills and they are running roughly $7,000 a year for all their utilities. And we’d done modeling, but I really wanted to know a little deeper how much energy we would be using. so we had our own utility bills after a year, but I was curious really exactly where we’re doing it. So, we installed an energy monitoring system on our electric panel, and we took it a little extreme. So rather than just doing the whole house and the solar, we actually went to do every single circuit breaker, you know, just little bit of overkill, but I was curious. and so we ended up getting a lot of interesting data. I can certainly tell the patterns of my family and what they’re doing. Very typical.

Kelly:                                  12:08                   When your children are out of bed, when they’re not supposed to be ?

Sri:                                     12:11                   I can tell when he’s turning on the TV without me knowing

Kelly:                                  12:14                   side benefits.

Sri:                                     12:16                   But in the end, after the year of a monitoring and looking at utility bills, we were roughly 1500 annually. So it was a huge difference.

Kelly:                                  12:26                   seven Thousand to 1500. wow

Sri:                                     12:28                   Part of that is converting fuels. So we did switch from oil to natural gas, but a large portion of that is energy savings and then solar generation.

Kelly:                                  12:39                   Right. That’s great. Did you get any incentives for any of the work, solar or otherwise?

Sri:                                     12:46                   So we actually got, between state utility centers and federal tax credit, we got roughly half of the solar cost of the solar system covered by incentives. And then we got probably another 10% of cost for insulation windows, high efficiency, mechanical equipment. And one of the interesting things is, my house was the case study that we used to get the Connecticut multiport heat pump incentive. So prior to that, they only did a single air source heat pump, just a one to one unit. That’s what they incentivized. And I actually had a single outdoor unit to multiple heads inside and they said, well, you just get the incentive for one. I said that doesn’t make sense. And then they said, well, you can put as many, you know, one-to-one combinations as you want and get the incentive for each one that way. It’s like, what’s the difference? multiport or single, it should essentially be the same and I don’t want to have, you know, four outdoor condensing units for no reason. So we actually worked with the utilities to revise their incentive program and we got incentivized.

Kelly:                                  14:09                   There you go. That’s great benefits of being the client and the consultant at the same time. Did you do anything in terms of automation? We hear a lot about smart thermostats and learning thermostats and did you do anything in that world?

Sri:                                     14:29                   Absolutely not. I have enough frustrations in the day dealing with my computer at work and having to do control, delete and resets and network issues. And when I get home, I really don’t want to have to deal with another computer. I like a simple light switch. If I want light on, I’ll turn it on. We kept the most basic thermostats. they are programmable but I don’t program them. we did all the work to make it an efficient house and I just set it to what temperature I want and then it runs.

Kelly:                                  15:07                   do you set it back manually during the day when you’re at work?

Sri:                                     15:10                   No. I mean we set a higher cooling set point than probably most people. But I like it that way. So we’re not over cooling it during the day, but it’s just a simple, I want to at 68 degrees in the winter, 78/77 degrees in the summer. Let it be.

Kelly:                                  15:31                   Awesome. Is there any difference between before you did this retrofit yourself and after in how you work with your clients or recommendations that you make to them?

Sri:                                     15:45                   Certainly, working with the Department of Energy’s Building American program, it’s very much heavily focused on energy savings. Looking at site or source energy, but it’s Btu saved, kwh saved. And that sort of the main metric that we’re using and a lot of times for clients, it was always about the return on investment, simple paybacks, everything was sort of about the energy-saved aspect to it. And going through this process, especially on sort of the health side of it, made it very clear to me that the way we present the value of a lot of these improvements needs to change. And so certainly health is one of the key ones that I focus on when trying to explain certain decisions. And it may not have a direct monetary payback, right? But productivity, long-term health, there’s a huge value to that. And then the other one is certainly comfort, its huge one that we always want.

Sri:                                     16:56                   You can always get comfortable with the house that sort of doesn’t work exactly as you want after a couple of years, but why? If you can make it comfortable for you rather than you adjusting to it, take the time to do it. And then the last one is really one I hadn’t really thought about before, which was noise. And making stuff a little tighter. Getting more insulation in the walls. The sound level significantly changes also. And so, especially with a lot of our high end clients, noise control or abatement is just as important as a lot of the other aspects that we’re trying to pitch to them. And so taking all those together, you can make a much fuller case to make a large investment into projects, rather than just focusing on energy.

Kelly:                                  17:47                   Right. Yeah, I think that’s really interesting and I’ve definitely come across a lot more of a focus on noise recently. And I don’t know if our equipment has gotten noisier or people are just more attuned or are less comfortable with just giving into the noisy equipment. So that’s really interesting anecdote. Was there anything that you didn’t do that you regret? That you might go back and change later?

Sri:                                     18:22                   I mean one we talked about was the exterior rich installation. And again, for that one, I think I do it more so than anything. I mean, I’m comfortable in the house, but from some other projects I’ve been on I’m certain there’s a noise benefit of having the exterior rich insulation. So I’ve gotten used to it, but you know, every morning we’re very much woken up by the birds chirping outside, and it’s like, well, it’s sort of nice alarm clock, but it’s sometimes it’s like, hmm, don’t really want that on a Saturday or Sunday morning.

Kelly:                                  18:54                   You want to wait for your own alarm clock.

Sri:                                     18:55                   The other big one is probably actually one that I’ve done quite a bit of research on. And so that was actually our kitchen range. The previous homeowners had done pretty extensive update on the kitchen, so I though it’s done. I don’t have to do anything more to it. But it was a microwave fan, and so its beautifully laid out, but it has a microwave over the range. And so I was like, oh, what are we going to do here? And it’s a vaulted ceiling, so you know, running a pipe also through the voltage, is just not aesthetically going to look nice, but we were able to figure out a way to duct it to the outside within the wall cavity. So it’s still a microwave range, but it is ducted to the outside. so it’s an improvement. It’s not perfect, but it’s an improvement.

Kelly:                                  19:52                   Yeah. Yeah. And I would just bring up at this point that the NREL study that looked at particulates and exhaust and things given off by everybody’s range.

Sri:                                     20:07                   Yeah. Aldehydes, particulate matter, Formaldehyde. Yeah.

Kelly:                                  20:12                   And that they recommend a minimum of, I think 200 cfm exhausts?

Sri:                                     20:18                   somewhere in the 200 to 300 cfm range, and a variable speed one, but it’s there on the Max range. If you have that along with the very good capture hood. So you really want a hood that extends all the way over your burners. If you could do that, that’s CFM range works fairly well.

Kelly:                                  20:38                   Great. Yeah. And I think they showed that a significant number of houses in the state of New York I think where the range was not operating properly

Sri:                                     20:50                   range doesn’t operate properly and people don’t turn them on. I mean, for it to be effective, you got to turn it on.

Kelly:                                  20:56                   That is an excellent point. And speaking of ranges, what are your thoughts on induction stoves?

Sri:                                     21:04                   So this is one project that I’m still trying to convince my wife of. originally it was a propane range and we converted it back to natural gas once we got that line. but two out of the four burners don’t work. and so we’re like, it’s time to replace it and doing sort of the studies looking at different things, I’ve sort of gone towards the induction idea. So we don’t allow combustion, burning a combustion gas anywhere in our house. It’s all sealed combustion at this point except for ranges just because we like it for cooking aesthetic. And so we’re really looking at moving to induction range. The main difference really is the pot selection and the amount of stuff that’s available now, I even have a cast iron pan that works for inductions. So I think that’s the route we’re going to be going and it will take care of some of the additional pollutants that we have to deal with when cooking.

Kelly:                                  22:19                   Right. Great. Yeah. And I think gas stoves are a big issue with passive house and I know that we have another episode on Passive House and Lois is not a big fan of those either. So, I also want to reference something that we’ve talked about, is the value of these improvements. And I know you wrote a blog post about the value of energy efficiency improvements on your house in terms of market value. can you talk a little bit about that and what your thoughts are?

Sri:                                     22:52                   The value or the lack of value? it’s one of the things that the department of Energy and the appraisal associations are all starting to get on board with this. the number of homes that have now been rated as energy star has gone into capacity where it’s starting to make an impact in the market. So people are actually considering HERS index energy efficiency and seeing a benefit from it. so you’re starting to see it creep into stuff. but you certainly have still the case of aesthetics upgrades, being the primary driver of what the price is. I just read an article the other day, if you paint your front door a gray blue color, you’ll add $6,000 worth of value to your house. And I was like, but I just put a generator. Did I get $6,000 worth of benefit back? Or I improved my boiler and I might get the cost of it back, but did I get $6,000 back? Ya know? It really hasn’t got to that point yet. But the bigger part I think that’s going to start getting into it is as we get more familiar with the health aspects of stuff, that’s going to have a huge impact on how we really value these homes.

Kelly:                                  24:15                   Yeah. I think that’s a great point. And I’ll, I’ll end on: if we are talking in five years on this podcast when we’re still around, of course, what would we be talking about then?

Sri:                                     24:34                   I’m guessing we’re going to all be living in domes electrochromic windows that will change depending on. No, I’m kidding

Kelly:                                  24:42                   Ah, you have a lot of big hopes for the next five years

Sri:                                     24:49                   We’re going to be talking about the same stuff. The big part that we’re doing is rather than being sort of on the leading edge, the early adopters, it’s going to be mainstream. So energy star is now getting more of a foothold, you’ll then start seeing passive house zero energy ready homes. All those things are going to start becoming what is demanded by the market rather than the nice extra feature that somebody does. And that’s really where I think the markets going to be going.

Kelly:                                  25:17                   That’s awesome. Great. Thank you so much for being on buildings and beyond.

Speaker 6:                        25:25                   Thank you for listening to buildings and beyond. For more information about the topics discussed today. Visit and check out the episode show notes. Buildings and beyond is brought to you by Steven Winter Associates. We provide energy, green building and accessibility consulting services to improve the built environment our professionals have led the way since 1972 and the development of best practices to achieve high performance buildings. I’ve production team for today’s episode includes Dylan Martello, Alex Mirabile, and myself. Heather Breslin, thank you for listening and we’ll see you next week.


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