Hidden costs

Well, as you can see not really "hidden." But these are the kinds of things that I didn't really even think about when I was doing our rough budget. None of the quotes I got from contractors included things like a propane tank ($2000), or the cost of excavating the trench for the gas line (900). And that's not even counting the $2k it cost to fill the thing with gas! (Now you can rent them, and they are free - you pay a surcharge in $/gallon. But then you have to keep it above ground, and the last thing we wanted was a huge propane tank to be the first thing we see when we come up the driveway.) Part of the reason it's a surprise cost is that it was a change; we had originally planned on using all electric. But gas made more sense for a lot of reasons that I didn't appreciate when we started making plans. (And of course we'll have to change that 220 outlet in the kitchen to accommodate our gas range...)

Now those are certainly identifiable costs if you do your research and are diligent about anticipating and calculating these items. I didn't do such a great job. So here are some items that I don't think I included in my initial budget (roughly outlined over at the budget page, which I've been updating a little lately):

Drilling the well: $11k (and we'll still probably need to add a filtration system);

Roof flashing: $3,275 (I knew this was a cost, but I thought it was going to be lower than this);

Cedar trim and cement board: over $3k (again, a cost I knew was out there but didn't know the amount);

Deck: going to have cost well over $12k by the time we're finished (5k in ipe, nearly 1k in ipe clips and fasteners, almost 1k in cedar, 2k for cable rail, 1k for pressure treated framing lumber, 1k for the labor I hired to help frame it). Now this probably would have cost twice as much if I hadn't done it myself.

Again, as you can see these are all pretty predicable costs. You can get estimates for all these things beforehand, or even roughly ballpark them. I think the biggest cost overrun I've had has really stemmed from not knowing what my materials were going to cost (and because Res4 calls for - and we've been using - top quality materials, it turns out they're pretty expensive). That's a function of being my own GC and doing DIY work and not having experience with pricing these items. I would expect that a real GC, particularly one experienced with prefab or even Res4 construction, would be much more adept at accurately predicting what this would have cost at the outset. At the end of the day I should be pretty close to our predicted cost because I'll have saved a lot of money on the basement, but we'll see just how close as these other costs continue to add up. My budget page, when all is said and done, should be a pretty exhaustive detailing of just what kind of costs you can expect to encounter when you do this kind of thing, and so at the very least you can use it as a starting point when evaluating bids from contractors or trying to gauge your own budget.