Cost difference of timberframe vs. traditional construction?
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I have an addition planned where we are adding a second story to a ranch. The current estimate for a traditional 2×4 construction is $123,000. I’ve thought about bringing in a timberframe company to provide an estimate, but don’t have any experience with timberframe and do not know what to expect. Would changing to timberframe construction necessitate an increase in budget?
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Traditional timberframing (with mortise and tenon joinery) is always more expensive than stick building. Additionally, it creates point loads at the base of the timber posts which would would be nearly impossible to carry properly to the foundation on an existing stick-framed house.
Jim,
"Would changing to timberframe construction necessitate an increase in budget?"
Yes.
Jim,
I apprenticed at a timber frame company several years ago, with the goal of cutting and raising my own structure. There are a lot of things to like about a timberframed structure. Cost is not one of them.
What you need to consider is that a timberframe needs to be enclosed. The enclosure is usually in the form of a stick-built structure OR SIPs. So basically you are building two structures. You ned the additional structure for insulation, plumbing and wiring chases, etc. When the house is built the timberframe becomes more aesthetic than anything else. 2 x 6 walls and SIPs do not need a timberframe for support.
Consider:
1) The quantity of wood required for the frame (those timbers are expensive). Timberframes are not resource efficient.
2) The labor. Although there are many companies cutting timberframes, the technique is highly specialized. It takes a higher level of craft to build a timberframe, therefore the labor is more expensive.
3) Engineering. You'll likely need an engineering stamp for the timberframe. More $$$ there.
All of these items are offset to a degree by the aesthetics and the relative permanance of a timberframe structure. In the end you get what you pay for . . .
Ted Benson is THE pioneer in American timberframing. He has several books on the topic. I'd recommend them if you're thinking of heading in that direction.
Good luck with the project.
"In the end you get what you pay for . . ."
Often you really don't. Relative permanence? Stick frame buildings are extremely robust, the technology dates from the early nineteenth century and surviving examples more than 150 years old are common. Aesthetics? If you like the look add a few non-structural timbers for show. A true timber-over-stick hybrid sounds like a structural nightmare with nothing to recommend it except obstinacy.
James Morgan,
It's a pleasure to hear another voice for putting function before form (which almost always translates to a more environmentally-responsible design).
Given today's habitations, authentic timber frames are more vanity than function. The aesthetic is wonderful but, as you suggest, can in part be met by including interior structural timbers with simplified joinery (half-laps and shouldered braces, for instance).
I've done this on most of my designs. Exterior double wall or trussed stick frames for maximum thermal efficiency with minimal forest resources, and a few strategically-located exposed interior load-bearing timbers for the aesthetic. If the timbers are sourced locally, they add an additional dimension of "greenness" to the product.
Robert, thanks for pointing out that heavy timbers within a stick frame can be useful structural members too, not just for show. We have used timber milled from clearing of the house site for this purpose. Very satisfying.
James - I guess when I said "relative permanence" I was thinking of Europe and the timber framed buildings there. In Dinkelsbuhl, Germany I slept in a timber frame house that dated back to the 16th century (it had been converted to a small hotel). There are a huge number of timber frame structures in Europe that date back 500+ years.
Then again, they probably used timber framing because they didn't have ready access to nails, or didn't like to cut the wood anymore than necessary (no power saws!).
Stick framing doesn't have that kind of history. We may like to think that stick built structures will last that long, but only time will tell.
If you look at the durability of "wood products" (and their susceptibility to moisture damage) I think you would agree that as the wood is cut into smaller and smaller pieces it becomes less durable.
Think MDF -> OSB -> Plywood -> Dimensional Lumber -> Timber
Perhaps it's a function of surface area. Or critical mass. Maybe I'm wrong. But that's the way I look at it . . .
The suggestion of using structural timber elements is very good.
BTW - It's not timber-over-stick, it's stick-over-timber. Most framers go with SIPS. Whichever way you choose, it is not resource efficient.
Perhaps it is obstinacy. Or wealth?
Robert - I agree with you. Today, timber frames are more vain than functional. I fell in love with the joinery. It took the apprenticeship to convince me that it just wasn't the right direction for a house.
I think the method is perfect for a barn, or any other "open" structure. There you have both form and function in harmony.
Daniel,
I don't think there is any correlation between the size of a framing member and durability. The critical factor is moisture, not wood volume.
For example, if a wood sill (on top of a foundation) is protected from capillary moisture and rain, it can last for centuries. If it gets wet, it will rot. I have seen 10x10 sill beams that are totally rotten -- and 2x6 sills that are dry and sound.
You can't fight a wet location by installing a bigger timber. Wood volume is irrelevant. Keep the structure dry, and it will last.
Daniel: when I wrote 'timber over stick' I was referring to timber framing an upper floor on top of an existing stick frame lower floor, not to the placement of the infill material used to insulate and weather-protect the structure . Good structural design generally avoids placing heavy point loads on top of a wall system designed to carry light distributed loads.
You are quite correct in your assumptions about the reasons for the prevalence of heavy timber frames prior to the early nineteenth century, not only in Europe but throughout North America also. The industrial revolution brought machine-made nails and water-powered and steam-powered saw mills which revolutionized construction technology. Before this time nails were made individually, by hand: no wonder oak pegs were the preferred fastener. Machine-powered saws were outlawed by the British government right up until the 1830's to protect landed interests and their agrarian labor economy.
A few heavy timber (cruck-frame) and half-timber structures from the fifteenth century and earlier survive in England. After that time masonry construction was largely adopted, partly because of extensive deforestation for shipbuilding, iron-smelting and agriculture but also because of the susceptibility of the timbers to rot in the damp climate.
Martin: "I don't think there is any correlation between the size of a framing member and durability."
Actually, there is. A fire will destroy a light-framed building much more quickly than a heavy timber frame, which tends to char and then insulate itself from further burning. A light wood truss will fail in a fire much faster than a stick-framed assembly.'
And, when we refer to the natural decay resistance of wood species, we're talking only about heartwood. Sapwood of all American native wood species is highly vulnerable to decay. A large timber is almost always center-sawn, containing much heartwood.
Good points, all.
Martin - I don't contest your point about keeping wood dry to avoid rot. Any wood will rot, given the right conditions. As you said, a larger timber doesn't solve the problem. Good building design and craftsmanship is the answer.
I do think it will take longer for a 10 x 10 timber to rot, as compared to a 2 x 6. Microbial and fungal decay happens more quickly as the surface area increases in proportion to the overall mass. Larger timbers also have a larger hygric capacity / buffer; a periodic wetting event would saturate the smaller member more quickly.
Keep them wet and both will rot. No argument there.
I used to travel to Europe for business, mostly Germany. I was always amazed to see brick in-fill used in the timber frames. It goes against everything in the book. Yet some of these structures have been standing for centuries. No capillary break between the wood and masonry, just clay brick and lime mortar packed tight against the timbers. They'll rot eventually, I know.
One thing about it, those old frames have great drying potential - in both directions. Maybe that's what makes them last. Still, it's a curiosity to me.
Daniel, you've hit the proverbial nail (or wooden peg) on the head.
Wood doesn't mind water as long as it can dry.
It takes many contributing factors to ensure a building's durability, and only a few of them are structural. Not setting it on fire is always a good plan, though if you do Robert is quite right that logwood will survive longer than kindling. However the most soundly constructed building will not last for long if it's poorly located, poorly suited to its purpose or not easily adapted to changing conditions. Stewart Brand's "How Buildings Learn" has some useful things to say about this.
'Good hat and shoes' is the old rule for cob (mud and straw) walls in the perennially damp southwest of the UK: a stone foundation that projects above grade and a good thatch with deep eave will keep this tenuous material together for centuries. The half-timber brick infill structures of Germany survive I think for similar reasons. The lowest exposed timbers need to be above capillary reach of ground water and outside the splash zone.
I have seen little in this thread about the fact that timber framing uses less wood than stick. Firstly, since there is less milling of larger lumber, and secondly because the structure requires less mass to provide equivalent strength and rigidity. By this yardstick, timber framing is the 'Greener' option. since the original question was about cost, I suggest that the cost to the environment might favour timber frame.
Steve,
Check your numbers again. A timber framed barn might use less structural lumber than a stick-framed barn, but a timber-framed house requires either stick-framed non-structural infill walls or petrochemical and wood SIPS panels, both of which are costly, resource-inefficient, and have a high ecological footprint.
A 2500 SF 2 storey house will have 6,000 BF of lumber in its load-bearing frame (including exterior walls, 2nd floor, 2nd ceiling and load bearing center walls, but excluding first floor if not slab). A similar timber frame house will require about 11,000 BF of lumber in its frame alone.
The last double-wall (modified Larsen Truss) 2,000 SF house I built required 10,000 BF of lumber for everything and resulted in an R-45/67 home.
A timberframed home doesn't "require" stick framed non-structrual walls or sips. I've been involved with cordwood stackwall, strawbale and hempcrete timberframed homes which used alternatives to stick framing and sips. Although more labour intensive the owners did save a bundle by doing much of the work themselves.
If you make the somewhat realistic guesstimate of a conventionally stick framed home costing between 40 to 60% of overall building costs, building a timberframed structure isn't really all that much more. Turn Key stick frame builders typical "turn key" cost estimates range in the in the %100-200 per square foot range. Many timberframe and log building companies advise clients of somewhere in near $150-300 (give or take) /sq. ft. turnkey costs.
Like so many things, cost, value and worth are not really black and white. If you have your heart set on building a timberframed structure it is entirely possible to build a similar home (albeit with tradeoffs perhaps (a smaller footprint or simpler design but a nicer aesthetics) but it is possible.
Like so many things in house building, the devil is in the details. You'll end up spending money (lots of it) building a new home. The most important thing is to spend it wisely and get the house that you want. I've seen houses with 10K worth of granite countertops and I've seen client built concrete countertops with cost a few hundred dollars. Both look fantastic and it made the homeowners happy.
Whichever way you go, you will want to get as many of your ducks in a row before breaking ground or submitting permits. Some costs will be fairly fixed and others have some wiggle room. Spend the wiggle room money on stuff that you really want, and try and save costs on stuff that isn't as important to you. Everyone is different in that respect and Vive le differnce!!!
Chris,
You're right that there are other infill alternatives. But cordwood infill requires an excessive use of forest resources (and cordwood masonry alone makes an excellent structure), and strawbale infill is very challenging to air-seal around the timbers (unless it's wrapped and not infilled).
But even your numbers suggest that the typical timber-framed house costs 50% more than an equivalent stick-framed home, and to suggest that it's important to spend extra for "what you want" undermines the most important element of green building, which is to build what we really need rather than waste resources on mere desires.
It seems like this has gotten off topic, but I'll use the opportunity to throw out a thought I've had that could be answered here. Isn't there quite a bit more embodied energy in KD framing material than the green wood used in most timberframes? Here in Maine you don’t have to drive more than a half-hour to get to your local sawmill, or you can use timbers milled on site. Obviously someone in a less forested area of the world has to think differently about a timberframe.
Recycled timber can also be used.
With a timberframe, if the roof is metal and the siding is clapboards or shiplap, there is no need for plywood or osb. A well built timberframe also affords the opportunity for a simple and improved building envelope since the framing is separate from the insulation/air/moisture barrier.
I’m not arguing here that timberframing is GREENER than stick building, but I think that each method has its benefits and drawbacks. And while there’s no doubt a timberframe is a little more expensive(not 50% overall, more like 10-20%), conventional wisdom is that a nicer, more attractive home will be cared for better and longer than others.
Ben,
You're right: green lumber has less embodied energy than kiln-dried lumber. But green lumber can be used for either stick framing or timber framing. My house was framed with green lumber: 2x6 studs, 1x6 sheathing.
Ben,
Not only can a stick-framed house be built with locally-sawn green lumber (that's what I've used for 20 years), but it's more resource-efficient to install siding directly over the framing (and WRB) without sheathing because - unlike a timber frame - the repetitive nailers are already in place as the structure, so there is no redundancy. Alternatively, one can use rough-sawn boards for sheathing or roof decking in place of high embodied energy plywood or moisture-vulnerable OSB.
Worth mentioning is that you'll get much more usable stick framing material out of a given tree than you do heavy framing timbers. Timber framing produces much more waste and unless you have a specific ecologically responsible use for all of the by-products it represents a poor use of natural resources. Of course this disregards issues of species and girth; additionally there are situations where using site-milled or recycled timbers for structural or decorative accents in a home can be very meaningful and rewarding, but for general construction purposes there is no question that stick framing sits far better with best practices for sustainable, renewable forestry.
Hybrid Timber Framing is so often misunderstood. Yes - there are lots of 'framer options' that can incorporate some basic timbers into a home for the 'look' but hybrid timbers can actually be structural - for instance, go heavy on structural timbers for entry and great room - but then 2 decorative beams in the kitchen for instance, 3 decorative gables on the outside. No timbers in the closet or the bathroom! (That can save on cost...)
The best explanation of this is probably: https://arrowtimber.com/hybrid-timber-framing/