Dirt oh yes dirt. It's a big eater of funds and sometimes can't be predicted.

We added 15-20% to some categories to be sure we'd be covering the 'surprises' and a couple blew the buffer right out of the water - dirt was one of them - framing was the other. Items like lumber/drywall that fluctuate really can be a bugger.

I've received a figure of $150 per dump trunk for clean fill but may have to pay extra as I'm not in a building hot build (a bit more rural).

How did your contract read that you had to pay for fluctuations in lumber and drywall? Although I thought I remember you where your own GC so that makes senses as I can't see a sub holding pricing for an individual.

I can 3rd the dirt. Our going rate here is also $150 per load, I was able to find it for $98/hr. The yard just happens to be right down the street from our house (literally 5 minutes) so I should be able to get more than 1 load per hour thus reducing my cost. Regardless, I have about $8k budgeted for fill and that's on the light side. (Random note: Just got a call receiving 50 free loads of fill from my county so that saved me a tonne -pun intended haha!- of money) If you need lots of dirt, put a sign on your property and post ads in your local buy/sell. I know on some jobs, my husband's company has to pay to dump their loads so if they can find somewhere to do it for free they go that route. (Unfortunately our property is just too far for them to come out)
Our #1 overages come from random expenses, a lot of which are lumber. I am constantly running to the hardware store to pick up supplies. It is these little things that add up very quickly.

Are you doing a self-build or hiring a contractor?

Good question, I'm hiring a builder.

Any reason you budgeted $8K for fill? Assuming you had to set your home further back than expected and have exposure?

whaas-yes owner build. We had a 'rough' quote but it was sorely underestimated and much more rough than we thought. Long story short it was someone we knew so we paid it but then called it complete as it was and moved on to someone else for the finish grade work. It definitely was not 'you get what you pay for' in that instance either. Paid a lot for a little.

We went over on excavation and subsequently foundation. That also resulted in some mods to the deck and patio railings. Total of 10k, but as a percentage, not too bad. In total we were 3% over. I worked like a dog to keep things within budget.

Lighting and faucets. Builder thought $100 for exterior lights was sufficient. We're building in the middle of no where. No street lights, no lights of any kind. Between the soffit cans, floods, and a yard light on aa 30ft pole, we're more like $1000. He also estimated $200 for kitchen faucets and $100 for bathroom. We doubled both of those. Also rock for the driveway was an overage. We're 30 loads in and might need that many more in the next couple of years...

Nothing structural, only selections for us. Home automation, lighting, hard surface basement flooring, countertops and faucets/towel bars/tp holders.

However, this was a builder financed build (so he would have something to show in the fall Parade of Homes) so he had his numbers in place for his own bank loan before we came into the picture.

For us it looks to be finishes. Seems pretty easy to really spend some money on fixtures and lights.

I believe the reality of the structural allowances (everything through drywall I mean) comes down to how well your builder knows his trade. Ours turned out to be within 5% of the estimates.

ground/landscaping for us.... $13,000 in grading (digging basement, moving dirt around) and sod/mulch, another estimated $5,000 for retaining wall, and estimated $10,000 for some foundation plants/trees, rocks. Builder estimated $5000 total.

Detail work was the big thing for us. Upgraded wood trim, stair parts, lp siding, exterior details, etc...all that and some minor overages on floors and some other items added up to almost $30k extra. We also had a surprise fee of over $5k that we had to pay to the city before they would give us permits. We didn't have to worry about non-allowance items going over budget though. That would really stress me out.

All thanks for the feedback! In some cases it seems things just change based upon mainly selections or surprises during excavation.

Halcyonbear,

Did you plan on different materials prior or was it not spec'ed out at contract?
That seems like a major $ figure for things that should have been known?

Some of our changes were things that just weren't really specified before hand, or underspecified. For example, we didn't know that the standard way to do an open staircase around here was to have a mini wall in the middle. We wanted it completely open, so we paid a little more to have them re-engineer and build the staircase the way we wanted it. Plumbing and electrical went up a little bit (not based on selections), but not by a lot.

Most however, were things that we decided to do differently once we were actually able to see choices in person, do more research, etc. One major thing we decided to do was go with LP siding, rather than vinyl. Also, turns out the cost for trim can go up by nearly a factor of 10 when you decide to do a 2 piece, wide poplar casing and thick baseboards. instead of mdf. That was really surprising to us. Just flat poplar instead of mdf would have been a difference of around $5k. We didn't even do any crown molding or anything, and nearly doubled what we had budgeted for trim work (we had budgeted for flat poplar).

We really thought about the way we live and the layout of our house before we signed our contract, so we didn't make any real changes to the structure. We didn't really run into any complicated lot issues (other than city fee), so that was nice. Before signing our contract with our builder we did go meet with a bunch of his contractors to make tentative selections that we could base the contract price on. However, I have to say, we're surprised by how much our tastes changed from our first meetings with people to now (just a matter of days 'til we move in).

One thing that became really important to us, which we didn't really realize when we started, was to add as many historic elements as we could afford in order to recreate the charm and character that we love about older homes. Since you really can't get authentic looking details without a lot more labor (and usually more expensive materials), that really drove the cost up on some items. Our carpenters probably love and hate me. Thinking about it now, most of that extra expense has gone to our various carpenters (that's totally ok with me, because they're awesome).

I do think you should have a little extra room in your budget that will allow you to be flexible with your style and choices as you go through the project. You probably won't make such extreme deviations from your original design concept, but I can all but guarantee things will come up that you'll want to do differently. Adding architectural details usually worth the extra money in my book, but it might not be to you. Still, if you can, I think leaving some room for things you don't really need, but come to love, is something you should definitely do.

Sorry for the long-winded response, but hopefully it's helpful.

Appreciate you taking the time to share more details!

You're super welcome!

For us it was overages on all the "allowances"...glass enclosures for the showers (over by 2k), closets (we decided to have our cabinet guy build our closets too, over by 10k), upgrades on the cabinets (the estimate was unrealistic, over by 30k), cabinet hardware (no idea, stopped counting), lighting (both chandeliers and under cabinet LED lighting), 5 zone Sonos sound system with in ceiling speakers. Fortunately we had some savings too. Instead of tiling all the bathroom showers and putting in all free standing tubs with separate tub fillers we did shower inserts on one shower (3k saving). We also went with ADT instead of a local company for security (another 3k saving). Instead of a built in grill we just bought a webber and had our builder pipe a gas line out to the lanai (about 6k savings). We are not completely finished yet. At the end of it all, we hope to keep the overages below 35k.

As mentioned above specify, specify and specify. IF you must have allowances have the labor included in the base contract and make certain the allowances are reasonable (most are not on purpose).

What millworkman stated above was dead on accurate for us. We actually went with the GC that was about the most expensive just because we felt he was the most realistic about his allowances. We are paying cash and unrealistic allowances would have been/will be a killer. It helped that we were very upfront about our expectations.

Most people say 10% for overages...I'd try to keep 20%. It's better to have a smaller, less-detailed home that comes under budget, IMHO.

And choose all your details EARLY and do NOT change your mind. Hope this helps!