There are basically two ways to estimate costs. You can use square footage and estimate cost per square foot, or you can work up costs from each line item in a construction budget. I did both.
Before I explain each, let me state the obvious. There is no upper limit on what a house can cost. If your house has a $100,000 photovoltaic system in it, that adds $100,000 to the cost of a house without that system. If you put 4000 sq-ft of antique wormy chestnut flooring in the house at $25/sq-ft that will cost $100,000, or about $60,000 more than nice oak flooring, and about $80,000 more than carpeting. Most of this post will relate the basic costs of building a high-quality structure, and not to the expensive jewels you might place in or on that structure.
Caveats: “market conditions” and “sweat equity.”
Estimates Based on Square Footage
Bigger houses will cost less per square foot than smaller houses. These costs are pretty good estimates for a house 3000-5000 square feet.
Custom home 3000-5000 sq-ft built by professionals…pretty much can’t do for less than $100/sq-ft. Plenty of homes are $500/sq-ft. I believe my actual construction costs will come out to about $133/sq-ft not including any design, engineering, or surveying costs (the costs you incur before you break ground). Everything, including all soft costs will probably come out to $150/sq-ft. Unless you are obsessive about cost management, I believe you should assume you will do worse than that, probably closer to $200/sq-ft. Most architects consider $200/sq-ft a low budget for a custom home.
What’s in square footage? All enclosed areas including garage, finished basement, and storage. All covered decks and patios. Mine does not include a large terrace, which has a foundation, pavers, and an awning that is 8 ft. deep.
Bank’s cost worksheet
Some good rules of thumb I used, and which proved to be pretty accurate in 2010:
Windows and patio doors cost $300-400 per unit, where a unit is an individual sheet of glass in a frame.
Interior doors are $200-400 per unit, depending on whether they are painted 6’8″ doors or finished wood 7′ doors.
Appliances: make a list…get quotes from usappliance.com.
Framing $7-10/sq-ft of floor space, not including materials.
Foundation $200/cubic-yard of concrete placed.
Excavation: could be as low as $10k for a flat lot with a crawl space or $60k for a steep wooded lot with full basement.
Fire protection (sprinklers): $1-2/sq-ft
Lighting fixtures: very little to a lot
Lighting controls: $0 to a lot
Tile: $10/sq-ft for installation
I finally had a few minutes to sort my actual construction expenses and put them in some reasonable categories. This is a brief summary of the construction costs.
First, the basic parameters of the house:
- 4348 sq-ft of space, including the garage
- 3-level “walk-out” design
- 2092 sq-ft footprint
- 4 bedrooms
- Cathedral ceilings in upper levels
- 5 bathrooms
- Enclosed deck on upper level
- Front and rear paver terraces
The total construction costs were $619,000. This is every dime I spent from the time we applied for a permit to the time we received the certificate of occupancy. It does not include the design fees (architect + structural engineer), which were about $60,000. It also does not include the cost of about 15 trips from Philadelphia to Utah, which cost about $10,000.
The cost comes out to $142/sq-ft of enclosed space. The square footage includes the garage but does not include the enclosed deck off the master bedroom, nor the covered terrace. I believe the calculation should include the garage, because the garage basically has the identical finishes as the rest of the house (same concrete, framing, drywall, paint, windows, casing, electrical, etc.).
In many ways calculating by the square foot is misleading. So, I’m providing a lot of detail on the costs by category in the following PDF file. This breaks down the costs by item with the usual “units” that are used to calculate the costs. For instance, the counter tops cost $7489 and comprised 135 sq-ft for a cost of $55/sq-ft.Continue reading
Whoa. It’s crunch time. We’re trying to finish this house in the next 10 days. There are about a dozen guys scrambling all over the place. The great room is still a wood shop, but the painters are trying to work around everything.
I suspect if you have a 12-18 month construction schedule you can avoid this. But, we’ll finish this house 7-1/2 months after breaking ground. That requires some overlapping of tasks.
Of course everyone wants to “go last.” More precisely, the painter, electrician, and plumber all declared that they should be the last people on the job. I suspect that if I had wood floors, the floor guys would also want to go last. The reality is that everyone ends up iterating a bit at the end to work around each other.Continue reading
I set up a fairly unusual arrangement for the Park City Modern project. Recall that this is a second home for me, and the distance between home and the job site is 2400 miles, about 7 hours door-to-door via Delta and a rental car. Thus, being on site every day was not feasible.
I visited a construction site with the architects last summer and talked to a contractor they had worked with before. This was a monstrous house , which had been under construction for over 2-1/2 years. It was 15,000 square feet and had a budget of $600/sq-ft. (That’s $9mm in construction cost for those who have a hard time with decimal places.) The GC boasted that the owner had only been on site twice. (Whoa.) I knew precisely then that this guy was not for me. His truck was too nice and his homeowner kiss-up skills were too polished. Those guys serve a very important need…getting a great house built for very rich and very clueless owners.Continue reading
My strategy with bid negotiation was to only solicit bids from subcontractors who were highly recommended by trusted sources. That way, I could hopefully focus on price without worrying I was getting bids from guys who do shoddy work. In most cases, I adhered to this strategy, although occasionally I got a bid from someone brought in by a related subcontractor (e.g., a heating guy who got a bid from a plumber friend).
In most cases I got at least three bids. I plotted the results of this bid process for the major subcontractors involved in the first phase of my project. These are the costs to do the work, including materials (except for framing, which is labor only). My house is about 3,700 sq-ft of living space with a 600 sq-ft garage. The flatwork quote includes all the concrete floors in the house, a concrete driveway, tinting the concrete, and applying acrylic sealer.
The results reveal why it is imperative that you get multiple bids. The difference between the total cost of this phase of work taking all the low bids and taking all the high bids is about $110,000, or more than half of what I’ll pay for this phase. That is, there can be a 50% difference in the total cost of the house depending on who you contract with. Again, in most cases, all of these subs are considered high-end guys and come highly recommended. The exception is the low bidder on excavating, on whom I had no information. I did not find the bid credible, which is why I didn’t take that bid. In some cases, I wanted to work with someone who was not the low bidder, but I negotiated with them to do the work for the low bid. In a few cases, I negotiated a price that was not as low as the low bid. This was the case for the electrical work. I honestly think the low bidder made an error in his bid. I just don’t see how he could do the electrical work for this house for $10,000 (which would end up being something like $25/box…a crazy number). I gave the low bid to another electrician and he worked his bid down to the point where he said he just couldn’t go any lower, and I left it at that. (It still seemed a very aggressive price to me, and so I was happy with the outcome.) In the case of the flatwork, I got only one bid. The flatwork guy was highly recommended and the flatwork is tricky on this house. The bid came in right at about what the RS Means guide said it should, so I didn’t get any further bids.Continue reading
I just spent a week in Park City negotiation bids on the Mountain Modern house. I’m building the house with the help of Steve, the broker who sold me the land. Steve lives a couple of miles from the site and has built a series of homes in Park City and elsewhere, so has a lot of local expertise. So, while technically this is an “owner build,” I’ve hired a “consultant” to arrange the subcontractors and to keep me informed about construction on a daily basis.
New home construction in Summit County is very slow right now. Just two building permits have been issued in the first 2.5 months of the year. As a result, almost no one in the building trades has any work right now.
Our strategy has been to select 3-5 subcontractors for each task based on the quality of their work, and then to make a final selection based on price. We have let these subcontractors know this is how we are proceeding.Continue reading
In this post I explain the analysis I did to understand energy efficiency design issues in my new house.
There are two basic contributors to the energy efficiency of a new house:
1. basic form, and
2. energy efficiency features.
By basic form, I mean what shape does the house have, how many stories is it, and how much window area is there. Those factors matter quite a lot. The most thermally efficient shape (ignoring solar factors) has very little surface area relative to its volume, basically a cube (if you assume the surfaces will be flat not curved). In the analysis I did, I assumed for a base case, a 3200 sq-ft 2-story house, with 8′ ceilings, on a 40′ x 40′ footprint. That’s a pretty boxy shape, but quite efficient thermally.
Windows are wonderful, except that they have just terrible thermal performance, even the really fancy ones. So, you basically have to decide how much glass you want and trade that off against how much energy you are willing to lose. About 12.5% of the wall area on an average new home in the U.S. is windows. I assumed that value in my base case.
OK, that boxy house with average windows in it will lose about 23,000 btu/hr keeping the inside at 70F on a 30F day, a typical heating day in climate zone 6, where I’m building my house. Note that this is not the maximum required heating capacity, which would actually be about 40,000 btu/hr for the -7F design temperature used to size boilers in zone 6. If you assume 200 days a year of 30F weather you get 8000 heating-degree-days, which is pretty close to the actual value for my location.
In order to give one of the design review committees a better sense of what the house would look like on the site, I made a quick sketch in Adobe Photoshop and Illustrator.
Here it is. (As with most photos on Baubilt, click to see a larger version.)
To do this, you need some facility in a photo editing tool and an illustration tool. Here’s what I did. First, I found a photo of the site that was oriented such that the front elevation of the house would be in the plane of the image. I then pasted the photo into Illustrator. As a separate layer, I pasted into Illustrator a line drawing of the front elevation from the architects. I then drew rectangles for the windows and filled them in with a color picked from windows in a photo of a neighboring house. I inserted boards for siding (rectangles filled with colors picked from siding photos). I drew the roof in and filled it with colors picked from neighboring rusted metal roofs. Then, I copied the trees and car from the photo in Photoshop and pasted them in front of the house. Finally, I drew in a driveway freehand in Illustrator. I pasted some rocks and trees in for landscaping. All of this took about 2-3 hours. I’m fairly good with these tools, but I was not fussy about the sketch. I’m pretty happy with the resulting image, which has been useful in communicating how the house is likely to look on the site.
In my first meeting with architects Eric and Andy (Carney Logan Burke Architects), they asked about my stylistic preferences, invoking the idea of a stylometer for gauging client style. Since I had picked them in part because I liked the houses they had designed for themselves, I was pretty confident the stylometer would give similar readings for us. Here is what I can articulate about my own stylistic preferences, to which I’ll add a few points which Eric and Andy brought to the table and to which I’ve come to subscribe.
My style elements (which were shared entirely by Eric and Andy):