All Forum Posts by: Jimmy Nguyen

@Shane WoodsGreat pictures.  I'm going to have to start doing the stairs on my new construction soon.  I've never done interior stairs before myself.  Any general things to look out for?  

How are you going to finish the steps?  

Forgot to attach picture of basement.  We put down foamboard insulation before the slab was poured for comfort and to give us the flexibility to put down finished flooring afterwards without fear of condensation issues.  

The basement will really be my workshop for my beekeeping business and potentially to do some welding, but it is huuuuge.  Any other thoughts on what to do with a basement?  

@Mike WoodYeah I estimated $80/square foot, but hopefully will come in under that number. Although the $80/square foot number doesn't count my semi-finished (insulated, heated, and drywalled, but no bathroom or finished flooring) 1600 square foot basement, detached carport, and covered front and rear porch towards the square footage.  If counting just the basement towards the square footage, I would be right around $40/square foot.  I'm not sure if people only count conditioned space in their costs/square foot calculations, but it seems like a lot of the outside areas add significant expenses to a project.  My biggest costs above a normal house is the standing seam metal roof ($19,000 or $7/square foot), 7 kw solar panels ($19,950 or $2.85/kw before tax credit), and triple pane casement windows ($16,000). I am going to be using LP smartside instead of vinyl siding which is going to cost an extra $3,000-$4,000.

I suppose when I build a spec house I would opt for asphalt shingles ($1.50/square foot) and do good double pane windows for half the cost of triple pane and still have it be good quality, energy efficient, and attractive.  Solar panels would be optional for the customer.  I would still avoid vinyl siding as much as I could, not necessarily for aesthetic reasons, but more for its environmental impact.   

As far as double stud walls or foam board insulation - I calculated that the extra cost to do those things would be about $3200 including labor. By using energy modeling, I calculate that I will save about 1700 kwh each year. I pay about $.16/kwh and that would amount to a savings of $272/year. The payback period for this investment would be 12 years. By using the rule of 72, that is a ROI of 6%. Not too bad if you consider that electric rates might go up over time. Of course, I'll never get back the actual $3200 as it will be stuck in my walls. For building "green" spec homes, I will have to balance the cost, ROI, comfort, and environmental impacts of each product.

For the solar panels, the payback period with federal tax deduction will be 9 years with a ROI of 8%. Those solar panels have good resale value if I ever decide to sell the home.

Honestly, I think I will be under budget for materials and subcontractors because I usually estimate them 5-15% higher.  Probably not a good thing if I want really accurate numbers, but I will continue to fine tune everything.  

How are building things in the Big Easy?  I imagine you have different circumstances you have to deal with like flooding and high winds.  

Putting on the double studs on my gable end.  

I am still framing out the double studs in my home.  It has been a lot of work, but the extra insulation, air sealing ,and lack of thermal bridging through the framing members will definitely keep my energy bills low. To quickly explain, thermal bridging through framing members means that heat will find an easy way through wood or metal studs, rim joists, and the top and bottom plates.  Heat is lazy and will seek the path of least resistance.  It will avoid that batt insulation (which is usually poorly installed anyways) and escape your house during the winter and enter during the summer through the wood studs, which only offer a R-value of about R-1 per inch, whereas cellulose or fiberglass insulation has about R-3.6 per inch.  As a general rule, every time you double R-value you cut heat loss by 50%.  In most construction, studs are placed 16" on center.  With headers and the extra jack studs needed for windows and doors, the wood framing can make up about 10%-15% of your actual wall mass, where heat can easily escape or enter.  Doing a double stud wall, which lets you place insulation (i.e. dense packed cellulose) between two separated studs prevents this thermal bridging and cellulose does a good job of blocking air movement.  Our double stud walls will be 10.25" thick with a true R-value of R-34. Compare this to a standard 2x4 wall spaced 16" o.c. that has a true R-value of about R-10 and you will find that our house will lose 75+% less heat than a standard house.  Additionally, we placed our studs 24" on center to have less studs and more insulation in those walls.  Another added benefit is that the house will be super quiet.  The houses out here are mostly on 10+ acre lots, but sound travels surprisingly far in open space.  

If I am going to do energy efficient spec homes and try to make a good profit, I probably would not do double stud walls and instead opt for applying exterior foamboard insulation to achieve the necessary insulation, air-sealing, and thermal break required for energy efficiency.  It would be difficult to train a crew to do double studs and it requires a lot of labor and somewhat creative carpentry skills - just imagine having to frame out every window and door twice.  Hanging up sheets of 4'x8' foamboard is something that contractors are used to and it's a lot lighter than plywood or OSB sheathing. The only drawback to using exterior foamboard besides window installation is that it will release potent greenhouse gases throughout its life due to the blowing agents used in its production. The blowing agents give the foamboard its great insulation properties.  Other negatives are that most foamboard is made from petrochemicals and use toxic chemicals to make them flame retardant.  The good news is that the energy saved by using this stuff will offset the its environmental impact in 3-10 years depending on how much and what type you use. The one exception is XPS foamboard, which is the worst type of foamboard you can use because it uses more potent greenhouse gases in its production.  Polyiso foamboard is probably the most environmentally-friendly foam insulation.  Luckily, I have access to recycled polyiso foamboard insulation nearby from a company called Insulation Depot, which is the only way I would use the stuff.  And it's discounted about 70% off the normal price of polyiso foamboard.  Here is a great place to nerd out on foamboard and its impact on our world.  

It seems I end up doing all of my exterior work in the winter and interior work in the summer! I have to time my construction schedule better. 

Here is a picture of the first house we built on our farm.  We used recycled 1 1/2" polyiso foam board on this house and taped the seams.  We attached the foamboard to the osb sheathing using long screws and extra wide washers.  

In terms of cost it looks like the materials costs will be a little bit more using recycled foam board insulation than doing double studs.  The recycled foam board insulation costs me $10/ 4'x8' sheet.  Buying it new at retail or even at a contractors price it can go for $30/sheet.  At $30/sheet, double studs definitely look better.  Where I lose money is in the labor. Foamboard goes up pretty fast whereas framing double stud walls (at least my way) is slower.  But with double studs you get to use recycled cellulose for insulation which has minimal global warming potential in its production and is made from 85% recycled materials like newspapers.  Also, polyiso foam board performs worse than advertised when temperatures get below 50 degrees and there have been concerns about shrinkage and gradually loss of R-value of foamboard as it off gasses.  As an alternative, we may consider using mineral wool for exterior insulation.  It is naturally flame retardant, has no global warming potential, no VOCs, and its made from rocks!  The only drawback is it can be expensive.

@Rich P. Everything you said makes sense. When the contractor dug out my basement they encountered shale at about 4 ft. The soils here in Fauquier County, VA in the triassic basin vary significantly within tens of feet. The area were I put my house straddled the line between deep and shallow soils. I was hoping to get the deeper soil, but alas I did not. They didn't have to bring out a ram hoe, but instead banged away at large chunks of rock with the excavator for an extra 2 days. This ended up costing me an extra $1500.

I laughed about your line about "don't let [the contractor] think."  As building science continues to progress, new techniques and technologies are making homes more maintenance-free and comfortable to live in, but its application is hard because people are used to doing things the way they have been doing them for years.  For instance, I had to apply a cement-based capillary break on my footer before the basement walls were formed to prevent moisture from traveling up the walls through the footer.  I also had to spend a lot of time installing a perimeter drain wrapped in a "burrito" of filter fabric and gravel.  These things the contractor didn't quite understand and so I had to do it myself, which costs me my time.  

The one thing I do like about working with different contractors is that they do offer pragmatic, cost-effective approaches that sometimes the "green" builders don't take into account.  Not everyone can afford to spend thousands of dollars to reach Passivhaus standards when it may take one hundred years to recoup that investment.  

I was thinking about doing a promotion like "We guarantee your monthly energy bills will be $50 or less or we'll pay for it."  But then someone might install a hot tub or charge their Tesla and we'd be in trouble.  

Thanks guys.  I'll check out those tools and get back to you.  

@Rich P.@Trevor Ewen@Shahram Zarshenas - If going by the CSI divisions for spec houses - what expense do you usually find varies the most or is most difficult to predict?  I am trying to specialize in energy efficient homes and I'm thinking that the thermal and moisture protection division will vary a lot due to differences in the climate the house is being built, precipitation, solar orientation of house, level of energy consciousness of buyer, price of solar pv, local source of recycled materials, additional labor to air seal and insulate correctly, etc. 

And as a follow-up to this question - do lenders value energy-efficient construction as much as they should?  Is doing an energy-efficient spec house risky because buyers might not understand the benefits and only value standard luxuries like stainless steel appliances, granite countertops, and his and her sinks?  

Hi,

I am in the process of building a house on my 13 acre farm.  I have already built a smaller accessory unit on the property.  In both cases, I have been using simple Google spreadsheets to keep track of my costs.  

Is there a tool that professional builders use that is better at categorizing and analyzing construction costs, which can lead to better cost-cutting measures and future estimating?  Would the basic QuickBooks software accomplish this or is there something more specific to the construction industry?

Thanks for any advice you can give.

If purchasing land that will not be able to tap into a municipal water supply or septic system, it would be advisable to see what type of soil the land has.  I guess even if you have the ability to tap into municipal lines, you should checkout the soil conditions to see if conditions are good for a basement or if you have the dreaded shrink/swell soil.  Shrink/swell soil may force you to change your footer size and reinforcements.  

An online tool that I always use is the USDA Natural Resources Conservation Service's Soil Survey tool.  You can type in any address or the street name your plot is on, zoom in and out, and then select the area you want to analyze.  The data is quite accurate as it is based on decades of soil surveys done around the country.  

If you think you have a good plot of land and good soil, I would still put a contingency in the contract that says the land must perc for a conventional septic system.  More and more counties are requiring higher cost sand mound filtration septic systems that cost $10,000-$20,000 more than a conventional septic system with the added cost of having annual inspections.  

Also, the county cooperative extension service is great to talk to about land.  They usually have a soil expert or a soil conservation office that can help you determine the characteristics of the soil. They may even come out and do some hand borings for you to determine how deep the soil is to shale or other limiting layer.  

Thanks @Tanya F.  Progress has been slow as I can only work on the house on weekends. Plus, my crew consists of my dad, wife, and I.  We would have had the walls sheathed by now, but the double stud wall and raised heel trusses are adding some time.  I think it will be worth it in the end when our energy bills are lower, our house is quieter, and we have less air infiltration.  

Our raised heel trusses allow the attic insulation to be a full 20" above the top of the outside walls.  Usually, rafters or trusses are built so that the actual rafter or top chord of the truss sits directly on the top plate of the outside walls.  Insulation gets pinched here allowing minimal insulation depth.  So you will get a lot of thermal loss in these areas around your ceiling.  

Here are some pics to explain.

This is a drawing of one of my actual trusses.  You can see that the height from the top of my wall to the top of the top chord of the truss is 20".  So I will have a full 20" of blown-in cellulose insulation running across my attic with a R-value of 66.  Our climate zone 4 requires insulation with a value of R-49.  Most houses can get to that with about 14" of blown-in insulation.  However, houses without raised heel trusses will really probably be only averaging a whole attic R-value of R-30 because the depth of insulation is reduced to near zero at the walls.  

The annoying thing about raised heel trusses is that you have to brace them by connecting them to your walls.  The International Residential Code requires that any truss that has a top chord 15.25" above the wall be braced for shear and uplift forces.  So that requires extra blocking and sheathing, which takes extra labor.  

We had to do blocking between each truss with 2x4s.  

Then we had to tie the trusses, blocking, and walls together with 1/2" sheathing and a lot of ring shanked nails. 

Hi everyone,

I am building a 2800 sq. ft., 4 br/3.5 ba home with a 1600 sq. ft. unfinished basement on my 13 acre farm in Bealeton, VA. Although this is not a spec house or custom build for a client, I am using this opportunity to prepare for starting an energy efficient home design/building company. I am keeping good records to see what my costs are. I am trying to do about 70% of the work, while subcontracting out for things like metal roof, solar panels, drywall finish, electrical, and ductless minisplit installation. Some of the challenging work I will be taking on is double stud framing, window installation, hydronic radiant heating, air-sealing, dense-packed insulation, plumbing, kitchen, bath, and siding (cement fiberboard and cedar). Two years ago, I built a smaller home on my property that is a 700 square foot apartment over garage, where we currently live. The cost of that house came in at around $80/square foot, but the price includes the cost of well, septic, drainfield, and a lot of clearing and excavation. This current house that I am building will share the same well, septic, and driveway as the previous house so I am saving on those costs. I hope to build this current house for $80/square foot. The other house will then become a rental property, most likely via Airbnb.

Originally, for this current house, I wanted to do a slab on grade, but putting in a basement cost only $25/square foot and makes it easier for me to do plumbing, ventilation, and other utilities.  In comparison, slab on grade would have cost me around $12.50/square foot. Also, a basement is a good place to shelter during a hurricane or tornado, phenomenon that are uncommon in my area, but with climate change anything looks possible.   A basement is also good for resale.  Although, this is a house I hope to keep until I am old, I still have to strike a balance between what I want and what a buyer might want just in case I have to sell.

The house includes a 700 square foot in-law suite for my parents to stay in for most of the year.  I'm still wondering how they are going to downsize from their current 3400 square foot house.  Ebay and Craigslist will be our friends when we try to sell all their stuff.  The in-law suite has some universal access design features including an open dining, kitchen, and living area as well as a curbless shower that I had to plan for during the framing stage.  The in-law suite provides me an opportunity to explore home design for the elderly as this is an area in which I am interested.  With our population getting older and nursing homes not an attractive option for some, I think smaller, single story, custom built homes for the elderly is a good market.  I will also be putting in hydronic radiant heating for my parents' section to keep them nice and cozy during the winter.  

My wife and I have 2100 square foot of the house and direct access to the 1600 square foot unfinished basement, which will become my workshop for my beekeeping business. The house is very open concept without a formal living room or dining room.  Some people prefer these rooms, but I feel they are a waste of space.  We included a 5 foot bumpout for a nice lounging/daybed area and upstairs the bumpout will be used for an office.  All together, we will have 37 strategically placed windows to allow for lots of light.  We will have a mudroom/utility room, carport, and 360 square foot porch that we will share with my parents. Naturally, we will have separate keyed entrances. 

In terms of energy efficiency, we are installing triple pane Intus windows with a U-factor averaging 0.18.  Our double stud walls will have a true R-value of 36 with minimal thermal briding through the studs.  Attic insulation will be R-72 throughout thanks to 20" raised heel trusses.  Air-sealing will be accomplished through tapes, caulk, gaskets, and spray foam. Heating and cooling will be accomplished through wood stoves (we have 5.5 acres of woods), ductless minisplits, and hydronic radiant heating. The house is designed with generous overhangs to take advantage of passive solar heating during the winter and shading during the summer.  Our metal roof is the color bone white and has a high solar reflectivity rating to help keep the attic cooler and reduce our cooling loads.  I don't think the savings will be dramatic from the white metal roof, but I really just like the color. Ventilation will most likely come in the form of an HRV from Zehnder.  It is expensive, but a necessity for air-tight homes to get the right amount of fresh air exchange in the house.  Unfortunately, our house does not have access to natural gas so we are all electric. Energy use modeling estimates that we will use 934 kwh every month.  In our area this equates to about $150/month. An 8 kw solar panel array will take care of 90% of this cost and with the federal tax credit, we should recoup the upfront costs in 12 years.

We started construction on this house in September 2015 and finally got under roof before the snowstorm in January 2016. I hope to have the Certificate of Occupancy (CO) by January 2017. Obviously, this is not a good timeline for spec homes or custom homes, but I can only work on the house on weekends and my crew consists of my dad and I and sometimes my wife, who is now pregnant! In the meantime, I am going to get my Class A Residential Builder's License this year and start the LLC. Some of my friends have expressed interest in me building a house for them so if everything works out I'll be building some custom homes in 2017. I just hope the banks and my clients value energy efficiency and universal access design as much as I do. But in the end, it's what the client wants and that they will get and more.

West view of house.  House is oriented directly south. Notice the beginnings of the double stud wall on the first floor.  We will complete the second floor double stud soon.

East view of house shows my parents' 700 square foot section with shed roof.  The shed roof allows us to place more windows higher up on the front wall to allow in more light.  We may incorporate a loft for my parents' guests since we the 14ft. front walls allows more headroom.

Possible color scheme.

Early hand sketch of first floor.  Some things have changed over the course of the design, but this will give you a good idea of how we wanted everything laid out.  In-law suite is on the right side.  The bedrooms for our section are upstairs.