# Green Building Annuity



## prisoner24601 (May 27, 2018)

Hi everyone. I wanted to share some experiences and numbers with the group after building a new house intended as our retirement place. Warning, I am a hard core energy geek and the house is likely one of the most efficient in Canada. But still the numbers may be of interest to some here. Here are the basics on energy use (everything- heat, lights, appliances, cooling, hot water, etc..) based on the Canadian Energuide for Homes standard:
Typical new build in Canada: 135 GJ
Our House (without solar): 41 GJ (Step 1)
Our House (with solar): -8 GJ (Step 2)

and to get our house to this standard, here is the additional building cost over an above what it costs to build a new house:
Step 1: $70,000 to meet Passive House standard building envelope (insulation, timber and tape)
Step 2: $30,000 to offset all energy use with a bit of margin

After a couple of years, I'm actually doing better than the rated numbers above but lets stay with those because they are based on Energuide typical consumption for family of 4. If I run the IRR on 25 year time horizon using current energy rates and historical energy inflation, I get

Step 1: inflation protected payment of $4,288 per year (6.3% return)
Step 2: inflation protected payment of $2,087 per year (7.8% return)

So, I've come to think of this as my privately funded annuity which offers the same advantages: tax free returns, inflation protection, risk free 'income' for life. You could also think of it as a 25-year inflation protected bond paying between 6.3 and 7.8% 

If you are building new or doing a big reno, this is a no brainer I think.

All the best and look forward to your thoughts


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## lonewolf :) (Sep 13, 2016)

A plug in hybrid car, plus grow lights to grow hydoponic food in the basement might save you a bit more money. With global cooling food will become more expensive

Hard to say if you will come out ahead or behind in the future? Houses can now be built using 3 D printing for pennies on the dollar. Some say nuclear fusion is the most abundant form of energy in the universe. Maybe nuclear fusion will be used in the future for pennies on the dollar for our energy. Interest rates could go above 6.3 & above 7.8% as well house prices can drop i.e., in Italy homes are being sold for 1 Euro.

If Everything vibrates sideways or vibrates higher for energy costs you come out ahead.


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## nobleea (Oct 11, 2013)

It will depend entirely on the price of energy in your area. Out here natural gas is practically free and power is very cheap. <$4/GJ gas and often under $0.05/kwh power.

When we did our new build, we looked to make simple changes to the construction to get closer to passiv house, without going crazy. With EIFS exterior and a bit more caulking and sealing at the framing joints, we were able to get down to 0.8ACH on our blower test. Considering passive house is 0.6ACH and the fact our incremental cost was probably <$2K over the standard construction, I'd say we did pretty well.


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## prisoner24601 (May 27, 2018)

lonewolf :) said:


> A plug in hybrid car, plus grow lights to grow hydoponic food in the basement might save you a bit more money. With global cooling food will become more expensive
> 
> Hard to say if you will come out ahead or behind in the future? Houses can now be built using 3 D printing for pennies on the dollar. Some say nuclear fusion is the most abundant form of energy in the universe. Maybe nuclear fusion will be used in the future for pennies on the dollar for our energy. Interest rates could go above 6.3 & above 7.8% as well house prices can drop i.e., in Italy homes are being sold for 1 Euro.
> 
> If Everything vibrates sideways or vibrates higher for energy costs you come out ahead.


lonewolf - I agree, it really depends on energy pricing and who really knows where that is heading. My bet is higher costs for de-carbonizing is in the cards -whether gas/oil is replaced by electric via nuclear, wind, hydro there are massive infrastructure costs to produce and distribute. I'm long AEP and XLU.... Thanks for your thoughts


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## prisoner24601 (May 27, 2018)

nobleea said:


> It will depend entirely on the price of energy in your area. Out here natural gas is practically free and power is very cheap. <$4/GJ gas and often under $0.05/kwh power.
> 
> When we did our new build, we looked to make simple changes to the construction to get closer to passiv house, without going crazy. With EIFS exterior and a bit more caulking and sealing at the framing joints, we were able to get down to 0.8ACH on our blower test. Considering passive house is 0.6ACH and the fact our incremental cost was probably <$2K over the standard construction, I'd say we did pretty well.


nobleea- As a transplanted Calgarian I know what you mean. I cringe when I think of how much gas I burned during the winter. Where I am gas isn't an option so we are starting at 3x your rate for electricity and oil is about the same. I'd be interested in what your total GJ use is with a near PH build. I saw this article and it got me wondering https://www.efficiencyalberta.ca/average-alberta-energy-consumption/


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## nobleea (Oct 11, 2013)

prisoner24601 said:


> nobleea- As a transplanted Calgarian I know what you mean. I cringe when I think of how much gas I burned during the winter. Where I am gas isn't an option so we are starting at 3x your rate for electricity and oil is about the same. I'd be interested in what your total GJ use is with a near PH build. I saw this article and it got me wondering https://www.efficiencyalberta.ca/average-alberta-energy-consumption/


I can tell you exactly what it is.
Our gas consumption is 153 GJ per year and our power consumption is 8050kwh/year. We have a rental suite about our detached garage. I suspect if you took that out of the equation (thus eliminating the additional need to heat the garage space), we'd be closer to 130GJ gas and 7800 kwh. Those are both above the average consumption around here, though barely. I don't think that air tightness has a very large impact on energy use. I think insulation and house design plays a far bigger role.

If one follows that per sq ft guide in the link you posted, we'd be using 140 GJ and 12,800kwh power. So bang on for gas and significantly more efficient for power.

If there's one thing I was shocked at, it was our water consumption. 10.7m3/mo which is below the 16m3/mo average around here and below the european average. And that included 3 pre school kids, a female tenant, and 1/4 acre of irrigated landscape.


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## agent99 (Sep 11, 2013)

It's been a while, so energy consumption numbers are no longer in my head. We have an older frame home with 2x4 studs exposed to Lake Ontario winds (they make quite a difference). No basement, so some heat losses through crawl space. 

We did an energy upgrade from previous electric baseboard heating to central high efficiency heat pump (that also provides A/C) (Mitsubishi). At same time we sealed house and added insulation. Energuide rating came in at 73 on 0-100 scale. Not great, but inspector thought it quite good considering age of home and what it had been!

We spent $20,000. (Government rebate just covered taxes!) Saving expected was $2000/yr or better for 10yr payback. It will actually be about 9yrs (we are almost there) Only maintenance required has been new air return filters - about $40/yr. Pretty good return compared with some of our investments 

If I was to build a new home, I think I would forget about gas and install a ground source heat pump. This along with sensible passive heating and some solar. I think this what the Building Codes are moving towards.


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## nobleea (Oct 11, 2013)

agent99 said:


> If I was to build a new home, I think I would forget about gas and install a ground source heat pump. This along with sensible passive heating and some solar. I think this what the Building Codes are moving towards.


I think the air source heat pump (as you have) are probably the way of the future. The ground source has quite an expensive up front cost which will scare many away.
Certainly if you can get away from hooking up gas in the first place, you automatically save the ~$50 in monthly fixed fees, which is a decent savings.


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## agent99 (Sep 11, 2013)

nobleea said:


> I think the air source heat pump (as you have) are probably the way of the future. The ground source has quite an expensive up front cost which will scare many away.


When retrofitting, an air source is no doubt a lot less expensive than a ground source (aka geothermal) heat pump. We looked at it, and our costs would have more than doubled with about 50% higher savings. However, if building a new home, the installation cost could be lower and maybe easier to accept as part of the overall home cost. The good thing about ground source, is that the heating medium stays at about same temperature through heating season. This keeps COP constant. With air-source, the COP goes down as the air temperature drops. Air source COP probably only 1/2 of ground source? We figure ours is about 2.0.

Anyway, I don't see us ever building a new home, so all theoretical


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## nobleea (Oct 11, 2013)

agent99 said:


> When retrofitting, an air source is no doubt a lot less expensive than a ground source (aka geothermal) heat pump. We looked at it, and our costs would have more than doubled with about 50% higher savings. However, if building a new home, the installation cost could be lower and maybe easier to accept as part of the overall home cost. The good thing about ground source, is that the heating medium stays at about same temperature through heating season. This keeps COP constant. With air-source, the COP goes down as the air temperature drops. Air source COP probably only 1/2 of ground source? We figure ours is about 2.0.
> 
> Anyway, I don't see us ever building a new home, so all theoretical


Indeed, it is certainly climate-specific in terms of ASHP efficiencies. They have gotten much better, even over the last 5-10 years.
Many COP's for GSHP don't include the energy required to run the pump which can be a significant amount. Of course below a certain temperature, there's no comparison, GSHP are better.

Almost all net-zero new builds around here will use ASHP with solar. Along with superinsulated walls and air tightness.


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## prisoner24601 (May 27, 2018)

nobleea said:


> I can tell you exactly what it is.
> Our gas consumption is 153 GJ per year and our power consumption is 8050kwh/year. We have a rental suite about our detached garage. I suspect if you took that out of the equation (thus eliminating the additional need to heat the garage space), we'd be closer to 130GJ gas and 7800 kwh. Those are both above the average consumption around here, though barely. I don't think that air tightness has a very large impact on energy use. I think insulation and house design plays a far bigger role.
> 
> If one follows that per sq ft guide in the link you posted, we'd be using 140 GJ and 12,800kwh power. So bang on for gas and significantly more efficient for power.
> ...


Thanks. I pulled numbers from my Calgary SFH house which was new in 1999 to compare. As a young family of 4 back in the day we were at 156 GJ Gas and 14,500 kWh electricity. I think my old 50 inch plasma TV was responsible for half the power:apologetic:! Your power use of 7800 kWh is typical, Energuide for homes model assumes 19.5 per day or 7118 kWh per year for lights and appliances (family of 4). On the building envelope, insulation and windows/orientation are big factors as you say and air tightness is too. At 0,8 ACH that is really good, I think many typical houses I see on the Energuide tests are 4-8 ACH or higher. Our house tested at 0.4 ACH but then we have no dryer, bathroom exhaust or range hood fan holes which means you need an excellent balanced whole house ventilator with heat recovery.


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## prisoner24601 (May 27, 2018)

Love air source heat pumps! They are definitely the way to go in all but the most extreme climates. We run 2 small Fujitsu units one up one down for all of our heating. Also our hot water heater is air source heat pump and so is our ventless clothes dryer!


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## agent99 (Sep 11, 2013)

prisoner24601 said:


> Love air source heat pumps! They are definitely the way to go in all but the most extreme climates. We run 2 small Fujitsu units one up one down for all of our heating. Also our hot water heater is air source heat pump and so is our ventless clothes dryer!


It is hard to find accurate technical data on heat pumps. I see that Fujitsu now advertise units that are good down to -15F. But I haven't found any data on how their performance varies with ambient temperature. 

When we were in the market, we needed a central unit that would still have a reasonable COP at low Ontario winter temperatures. There were just two. The Mitsubishi Zuba and Carrier. Both published performance characteristics. The Carrier initially had a higher COP, but as temperature dropped it's COP dropped off very quickly. This made the Zuba the only unit at the time that would still operate with a reasonable COP at say -23C. And it was only available in one size. At that time, Mitsubishi had one wall hung unit that might have worked, but I don't think anyone else did. That was all almost 10 years ago, and I am sure things have changed. 

Don't know where you are, but no doubt air source heat pumps, central or wall hung would be ideal on the West Coast. Care needed when choosing them in colder climates.


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## prisoner24601 (May 27, 2018)

agent99 said:


> It is hard to find accurate technical data on heat pumps. I see that Fujitsu now advertise units that are good down to -15F. But I haven't found any data on how their performance varies with ambient temperature.
> 
> When we were in the market, we needed a central unit that would still have a reasonable COP at low Ontario winter temperatures. There were just two. The Mitsubishi Zuba and Carrier. Both published performance characteristics. The Carrier initially had a higher COP, but as temperature dropped it's COP dropped off very quickly. This made the Zuba the only unit at the time that would still operate with a reasonable COP at say -23C. And it was only available in one size. At that time, Mitsubishi had one wall hung unit that might have worked, but I don't think anyone else did. That was all almost 10 years ago, and I am sure things have changed.
> 
> Don't know where you are, but no doubt air source heat pumps, central or wall hung would be ideal on the West Coast. Care needed when choosing them in colder climates.


I'm in Nova Scotia and we don't really see extreme cold. My Fujitsu units put out rated heat down to -21C with COP of 2. At more moderate temperatures around 0C COP ranges between 2.5-4.5 depending on compressor speed. We just set it and forget it which helps the COP since house loses heat very slowly so the variable speed compressor rarely runs at full load (high speed=more electricity). I visited a PH in Ottawa where they used only a small electric heater in the ventilator supply air stream. You can get heating demands down to a few kW in these houses pretty much anywhere, it's really just a function of how much insulation you are prepared to install plus other construction details. The house in Ottawa had walls that were over 20 inches thick and I expect 12-16 inches of foam under the slab. Here is a nice test report if you are interested in COP data with temperature https://www.nrel.gov/docs/fy11osti/52175.pdf


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## fireseeker (Jul 24, 2017)

agent99 said:


> It's been a while, so energy consumption numbers are no longer in my head. We have an older frame home with 2x4 studs exposed to Lake Ontario winds (they make quite a difference). No basement, so some heat losses through crawl space.
> 
> We did an energy upgrade from previous electric baseboard heating to central high efficiency heat pump (that also provides A/C) (Mitsubishi). At same time we sealed house and added insulation. Energuide rating came in at 73 on 0-100 scale. Not great, but inspector thought it quite good considering age of home and what it had been!
> 
> ...


Agent, how does your system work when it gets below -20C? What do you have to augment the air source heat pump?


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## agent99 (Sep 11, 2013)

fireseeker said:


> Agent, how does your system work when it gets below -20C? What do you have to augment the air source heat pump?


Our heat pump installation has no supplemental heat. The original baseboard heaters are still in place and our plan was to use those if the heat pump reached it's limit. We have one small breakfast room with a lot of glass and exposed on 3 sides to outdoors and wind. Crawl space under. Occasionally, we turn baseboard on in morning because that room is slower to come up from night to daytime set temperature. The Mitsubishi Zuba only came in one size. My calculations said it should provide all of the heat for the main living area of our home down to -23C. That has proven to be about right. For one prolonged period at about -23C with wind, we were only just able to maintain an inside temperature of 19C. (set at 20C). Wind is a big factor here. We don't have ducts to the two bathrooms. They have minimum heat loss to exterior. The baseboard thermostats are set to keep those reasonably warm. 
We have another part of home that is not serviced by the heat pump. Still on baseboards. Considered a mini-split, but the ones that would work at our min winter temperatures (only one model of Mitsubishi at time) were too expensive.


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## agent99 (Sep 11, 2013)

prisoner24601 said:


> Here is a nice test report if you are interested in COP data with temperature https://www.nrel.gov/docs/fy11osti/52175.pdf


I noticed that most of test data was at higher temperatures than we can experience. For Fujitsu, only one point below 8F. Then they projected low temperatures with a straight line. They were most interested in Pacific Northwest, so perhaps lower temperatures were not of as much interest. However, for most of Canada, they are.

When I was doing this, I compared the *heat output* of the Zuba and the Carrier at low temperatures rather than COP. The Zuba continued to provide the required heat output down to low ambient temperatures, albeit with reduced COP. The Carrier did not and would have required a lot of supplementary heat, even although rated COP was higher (Because ratings are quoted at higher temperatures). In fact Carrier rep suggested not using it, partly because compressor did not like stop/start at sub zero temperatures. 

Just a comment on that Ottawa house and the 12-16in of foam under slab. Except for the perimeter, I would expect heat to be gained by not insulating. Center of earth is hotter! - Heat should flow into the home! We have low unheated crawl space. Undersides of home floors are not insulated. Crawl space perimeter walls are insulated but only where we could get at them. Crawl space is sealed in winter and ventilated in summer. Old home and not perfect, but temperatures in unheated crawl space stay reasonably high - Haven't checked for a while, but I recall it being stable at something like 9 or 10C. Floors not cold.

We could have done a lot more, but happy so far with the return on our $20k! Might look at a minisplit for two rooms in other part of home. They will have to have come down in price to be viable! (Our home is almost all on one one floor - not good for mini-splits.)


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## nobleea (Oct 11, 2013)

agent99 said:


> ed a lot of supplementary heat, even although rated COP was higher (Because ratings are quoted at higher temperatures). In fact Carrier rep suggested not using it, partly because compressor did not like stop/start at sub zero temperatures.
> 
> Just a comment on that Ottawa house and the 12-16in of foam under slab. Except for the perimeter, I would expect heat to be gained by not insulating. Center of earth is hotter! - Heat should flow into the home! We have low unheated crawl space. Undersides of home floors are not insulated. Crawl space perimeter walls are insulated but only where we could get at them. Crawl space is sealed in winter and ventilated in summer. Old home and not perfect, but temperatures in unheated crawl space stay reasonably high - Haven't checked for a while, but I recall it being stable at something like 9 or 10C. Floors not cold.


There is an ongoing debate about the value of insulation under the slab. Some say do it since the earth's temp is 12-14C and so you lose heat in general. Others say it's very little loss and sometimes a gain. There is no definitive answer. There are pages and pages of discussion on greenhome building advisors message boards.
We put 4" of foam under our slab. The basement has 10' ceilings and the frost line around here is around 4' in the winter. It's very warm down there, even with bare concrete.


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## agent99 (Sep 11, 2013)

nobleea said:


> There is an ongoing debate about the value of insulation under the slab. Some say do it since the earth's temp is 12-14C and so you lose heat in general. Others say it's very little loss and sometimes a gain. There is no definitive answer. There are pages and pages of discussion on greenhome building advisors message boards.
> We put 4" of foam under our slab. The basement has 10' ceilings and the frost line around here is around 4' in the winter. It's very warm down there, even with bare concrete.


In theory, heat must flow from the earth up into our homes. We may know what the temperature of the earth is at certain depths outside of buildings at different times of the year. We use that for deciding on depth of foundations water pipes etc. When we pour a slab over a large area of land and then keep temperature above that at say 20C, we impede the heat flow and should receive a gain in heat from earth. The earth below our slab should get warmer. But that earth will try and equalize in temperature with the soil outside our building perimeter. It will always be warmer, but by how much depends on size of slab and how far from perimeter walls we measure the temperatures. 

Accurate calculation of this requires finite element analysis, a knowledge of the soil properties as well as the Earth's heat flux for the location. Not practical, so simpler methods have been developed. Most of those suggest that you really only need to insulate for a certain distance from foundation wall under the slab. But in our climate, fully insulating probably does no harm. But putting 1 ft in middle of slab? 

We didn't have this problem. For crawl space upgrade, recommendation was to just insulate perimeter walls. Not much choice anyway - clearance under floor joists goes from 3ft to 1ft. Not ideal working space


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## prisoner24601 (May 27, 2018)

agent99 said:


> I noticed that most of test data was at higher temperatures than we can experience. For Fujitsu, only one point below 8F. Then they projected low temperatures with a straight line. They were most interested in Pacific Northwest, so perhaps lower temperatures were not of as much interest. However, for most of Canada, they are.
> 
> When I was doing this, I compared the *heat output* of the Zuba and the Carrier at low temperatures rather than COP. The Zuba continued to provide the required heat output down to low ambient temperatures, albeit with reduced COP. The Carrier did not and would have required a lot of supplementary heat, even although rated COP was higher (Because ratings are quoted at higher temperatures). In fact Carrier rep suggested not using it, partly because compressor did not like stop/start at sub zero temperatures.
> 
> ...


On the Ottawa PH like ours, it is 2-storey slab on grade so edges of the slab are well above the frost line and require special insulation skirts plus the soil temps under the slab around the perimeter are much lower than if you had a full height basement. I'll admit PH is a bit extreme because it prescribes a strict limit for heat loss and you've got to properly insulate every exterior surface of the building envelope to have any hope of getting there.
In any case, negative heat flows are definitely happening 24/7 in any house if you are at 20C inside the conditioned space and 14C under the slab. For large footprint house in a high HDD area the cost of heat loss through the floor is going to be a good chunk of your home heating bill. It's only a question of how much insulation and how low you want to get the heat loss. I think code in most areas is now R-10 (2 inches) under the slab which probably gets you to a reasonable level of energy efficiency. With a crawl space the conditioned space boundary is the floor above the crawl space so it would make sense to focus insulation/sealing on that surface first.


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## agent99 (Sep 11, 2013)

prisoner24601 said:


> With a crawl space the conditioned space boundary is the floor above the crawl space so it would make sense to focus insulation/sealing on that surface first.


That is only true if crawl space is ventilated or open. And then, you also need to insulate all pipes and ducts if there. 

For sealed crawl space, insulating inside or outside of walls is recommended by Natural Resources and others. In fact it was one item I had to do to get my EcoEnergy rebate! ($1000 for adding R24 insulation to crawlspace walls!)

https://www.nrcan.gc.ca/energy/effi...ng-the-heat-in/basement-insulation/15639#a6-3

We didn't add the suggested vapor barrier on floor because floor could not be fully accessed and sealed. In any event, we have no moisture, no mould. Just thin soil layer over limestone. In summer we open vents and run an extraction fan (low energy!)


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## Prairie Guy (Oct 30, 2018)

prisoner24601 said:


> Hi everyone. I wanted to share some experiences and numbers with the group after building a new house intended as our retirement place. Warning, I am a hard core energy geek and the house is likely one of the most efficient in Canada. But still the numbers may be of interest to some here. Here are the basics on energy use (everything- heat, lights, appliances, cooling, hot water, etc..) based on the Canadian Energuide for Homes standard:
> Typical new build in Canada: 135 GJ
> Our House (without solar): 41 GJ (Step 1)
> Our House (with solar): -8 GJ (Step 2)
> ...


The $100,000 extra would not pay off in my situation due to the already low energy costs. I have a 50 year old, 1000 square feet, 2x4 construction house and my total energy costs per year are about $1400...$400 for natural gas and $1000 for electricity.

If I was building new I'd insulate very well and use triple pane windows but spend nowhere near $100k in additional costs to gain what might be negligible returns.


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## prisoner24601 (May 27, 2018)

agent99 said:


> That is only true if crawl space is ventilated or open. And then, you also need to insulate all pipes and ducts if there.
> 
> For sealed crawl space, insulating inside or outside of walls is recommended by Natural Resources and others. In fact it was one item I had to do to get my EcoEnergy rebate! ($1000 for adding R24 insulation to crawlspace walls!)
> 
> ...


good to know thanks for clarifying that


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## prisoner24601 (May 27, 2018)

Yes, I got that from a few trades on the build. Funny no one ever asks what the return on investment is for the upgraded kitchen, floors and cabinetry...


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## agent99 (Sep 11, 2013)

prisoner24601 said:


> Yes, I got that from a few trades on the build. Funny no one ever asks what the return on investment is for the upgraded kitchen, floors and cabinetry...


My wife claims those upgrades will increase the resale value. But we are not selling anytime soon anyway


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