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estimating cost when building your own house

3K views 19 replies 10 participants last post by  Daniel Holzman 
#1 ·
How does one come up with estimates of construction costs when designing their own house?

I want to consider different designs and ideas and how much they might cost but it seems like it would be quite annoying to be asking a general contractor to give me bids when I don't have a final design.
 
#17 ·
if you do work with an architect and they help determine price. MAKE SURE THEY HAVE EXPERIENCE IN PRICING and actually know what labour rates are ,

just recently we were asked to bid on a large custom home build. the architect had a ton of high end custom stuff spec`d on teh house and told the homeowner it should run them about $600,000 however when we price it up along with 2 other contractors everyone came in at over $1 million. thus sending the homeowner back to the drawing board to get the pricing down. they can probaly find a contractor will do it for what the architect spec`d howeveri can guarentee the work wont be very good if it even passes the inspection stages which in turn could more than double the actual build price
 
#4 ·
Are you able to pay cash for this build or at least have a huge down payment and really good credit and lots of collateral and already own the land free and clear?
Reason being no lending organization is going to be lending money to a first time home builder.
Just how much free time do you have? Building a home requires a whole lot of time.
Got a place to live while this is being built and able to afford paying for two different places.
You''ll get over the thinking this is going to be fun really quick when you find out just how much "fun" it is having to deal with subs that you have never dealt with before.
You will soon see why it's almost always faster and cheaper to at least hire a GC to get this house dried in. He or she is going to know which subs are going to show up, know what there doing so there's no do overs.
No sub is going to put a once shot deals needs above a GC that they have been counting on for work for years.
He's going to know what needs to be done in what order and exactly what materials, equipment needs to be on hand.
All day long there's going to be decisions that will need to be made that can not wait for someone to figure it out or go on the net to ask how something needs to be done.
Someone needs to be on site that knows what there looking at to know if things are being done right and to code. No sub is going to wait and come back later when you make a decision.
Everyday that building is not dried in is going to take a toll on any materials left exposed to the weather.
 
#18 ·
I see what you're saying but wouldn't a certain amount of delays be assumed at all stages and thus you'd always be on time or ahead?
No, if you assume delays everywhere, you will use up all that time and still be late.

Unless you are an ace at critical path scheduling and have a system to track the amount of delay that has already accumulated, the easy assumption is "built in delay (or float)" will cover it. Every one goes on fat dumb and happy until it blows up in your face.

Do you even know what the critical path of your project is ? You can end up working on (or having a sub work on) a non critical activity when you could be working on the critical activity that will cause a day for day delay in the entire project.

Experienced GCs know where the critical path is, at least most of the time. Even they get surprised occasionally by a sub-critcal activity that used all available float and has now become the true critical path activity.
 
#2 ·
Work with an experienced architect and have a GC also hired for periodic review for costing if you want to create something that works for the construction world instead of just the design world. Also, explore new homes for sale in your market. You can get an idea what it costs to build in a subdivision by an experienced builder. Fully custom will generally be more sometimes substantially so. It's the difference between haute couture and the designer clothes that you can buy at a high end department store. Then there are the plan mills that you can buy existing home plans on the internet. Those vary between a Macy's quality to below WalMart quality. Here, in my low cost little corner of the world, a fully custom home at a mid grade finish level runs roughly around $175-$200 per square foot. Existing homes of that same build level can be purchased for $100-$125 a square foot. Higher end projects have correspondingly higher costs to produce. I'm involved with a 10,000 square foot build right now that's coming in at around $600 a square foot because it's an unusual design that needed a lot of engineering and has lots of custom specialty details. And I live in one of the cheapest construction climates that exists.
 
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#12 ·
Why wouldn't a sub do one shot deals?
Thats not what Joe said.
He said "No sub is going to put a once shot deals needs above a GC that they have been counting on for work for years."

Translation -your work is going to be delayed. The sub is going to do the rush jobs that his regular GCs need done, before doing yours. Usually, you won't even find out about the delay until his guys don't show up. Then you have to slip the work of the next sub. They may not be able to accommodate your slipped schedule, so you get additional delay. It will all get done, but not to the schedule you originally planned on.
 
#13 ·
I can attest to that....

Basically, you become fill in work. A sub is going to be faithful to a GC...and a GC uses a sub because he does good work and is faithful. I have a couple of friends who are GC's....and one of the things they hate is having to find new subs...they like subs they can call up and depend on to be there when they need them...and do a good job. As one guy put it, you have to 'break them in' to your way of working.

On the flip side....I got some good pricing because I was 'flexible' on time and they used me as fill in work.
 
#16 ·
They do ours a little different...as long as you have incremental inspections along the way, then you can keep the permit open. In my case, I'm going on 2.5 years so far....and I'm about 6 months away from the final.
 
#20 ·
An alternative to having a GC or the architect cost your house plans is to have a professional estimator price up the job from the plans and specs (if you have specs). It might cost you a thousand or more dollars to get a professional estimator to do the takeoffs and prepare the estimate (this is NOT a bid, this is an estimate for your use in budgeting and negotiating with contractors). Having an independent estimator do the work has some advantages, since they have no financial incentive to skew the cost, and they may have some good ideas on how to save money and/or time on the project.
 
#3 ·
@Live_Oak so I guess I feel like if I come up with a design, basic or full and ask a GC or architect to come up with a bid I would be wasting their time as I imagine it takes them some time to work out a bid.

I especially feel this way because I will be doing the general contracting and they wont get the job no matter what, I want to do it for the fun and because in my limited experience if you want it done right you do it yourself.

Are most general contractors / architects open to consulting on an hourly basis for this type of thing?
 
#9 ·
@Live_Oak so I guess I feel like if I come up with a design, basic or full and ask a GC or architect to come up with a bid I would be wasting their time as I imagine it takes them some time to work out a bid.
so hire the builder to provide cost figures, pay him for his time. you get accurate numbers and they are compensated for their time.
 
#5 ·
Depending on your location you may need an architect/engineer stamp to get your building permit.

Many people underestimate the value and function of a good GC. A good GC understands the timing of a project, and knows the good and bad subs. If you are in a busy construction area, how much priority are the subs going to give to hellonko's one time project, over company XYZ's multiple projects?

You mention your limited experience. Are you ready to tackle the task of being a GC for a home?

I GCed my cabin project, but was lucky enough to hire a framer who taught me a lot while on the go. Being your own GC is a challenging rewarding experience, but your money savings will be offset by delays.
 
#7 ·
Building your own home is a full time job. I suggest you start with a smaller project first. If you own the property, build a shed on it that can house the needed construction equipment and supplies. You'll have to design it up to current codes and get permits and insurance for that as well, but it's a lot simpler than a home to begin with. If you can do that, then you've gained valuable experience as to what 1/10 of building a home is like.

We built our own 1800 sf shop/garage, and built it up to residential standards with heating and cooling. And we already owned a BUNCH of tools and had a barn to keep the materials in. It still took us 2 years and 40K. And that was 15 years ago. It would probably take even longer now that we're older, and it would certainly cost more! We didn't have to deal with plumbing, or any extensive electrical, although we did have to comply with seismic and high wind requirements.

All I'm saying is don't bite off more than you can chew. Know your limitations. And the best way to find out your limitations is to start smaller.
 
#8 ·
As someone who is on the final stages of a 2-story addition to my house....yea, Joe pretty much has it..

I was my own GC...in fact, except for the foundation, roof and stucco...I did ALL the work myself.

The project has taken twice as long as I expected (over 2 years instead of 1)...and the cost is about 50% more than I planned.

Mind you, to some extent, I think the final outcome is better....because it is mine, my attention to detail was higher.

When it's all done...I'm pretty sure I'm going to come in around $80/ft, less than half the going rate if a GC did all the work.....but not without it's trials and tribulations..

If you want an idea...click on the link in my signature...
 
#10 ·
@Joe_caption - Yes I have a cash budget as much free time as I would need and a place to live free as well as non working income.

Why would I have to deal with subs I have not before? I already know good foundation / electrical / and plumbing subs that I have used before and trust.

Why wouldn't a sub do one shot deals? Work is work. Wouldn't they want the good word of mouth? I know they are not that busy. The electricians have done things from a half house rewire with a new panel to moving a 220v dryer outlet.

Also it is not like I am going to run out the door right now and start building something. I would find a local GC figure out a way to ride along through the entire process.

@ddawg - Thanks. Are you saying that even though your costs were double what you planned your final cost will still be half of the typical costs per square feet? For example: You thought it would cost $40 but it cost $80 but it would have cost $200 with a GC? Thanks for the link too I will read through it when I have a bit of time. How did you come up with your initial prices so you had a rough idea of what you could / couldn't do?
 
#11 ·
@ddawg - Thanks. Are you saying that even though your costs were double what you planned your final cost will still be half of the typical costs per square feet? For example: You thought it would cost $40 but it cost $80 but it would have cost $200 with a GC? Thanks for the link too I will read through it when I have a bit of time. How did you come up with your initial prices so you had a rough idea of what you could / couldn't do?
Cost was 50% more....time was 125% more

Some things did come in on budget....foundation...calculated $7K...if I exclude all the extra hold downs (earthquake stuff), it was on budget...

Roof...on budget

Stucco...Close...real close...but I also ended up with it turning out better than I originally expected plus we did more stucco than originally planned...for example, we striped off all the old stucco on one wall and re-did it all the way to the end. Considering that we insulated that whole wall and replaced the windows....in realty, I actually saved money if you factor in doing it after the fact or as a retrofit.

As with any project, it has the typical 'creep'....the typical "You know, it would be really neat if this was 'this' way instead of 'that' way." Part of the extra cost is windows and doors....Windows alone was over $7k...but for that, I got double panned, low E, fiberglass outside, vinyl inside.....the noise reduction alone is well worth the extra money...

We are starting to get our cool weather now...I don't have the heat hooked up yet...but we have found the temps to be great...the house originally did not have any insulation in the walls....this is California...so no big deal...but we ended up insulating all but one section of wall. The noise reduction and better temp control has been well worth it. I'm sure that once I get the rest of the drywall up and plug up the remaining air leaks, my temp control will be fantastic.
 
#14 ·
@Oso954 - I see what you're saying but wouldn't a certain amount of delays be assumed at all stages and thus you'd always be on time or ahead? Or you would know how reliable the subs are and have a pretty solid idea of if they will be on time?

I know what you are talking about. When the HVAC people came for the remodel I am doing, the guy didn't have the right plenum and other things to set it up so they had to order those get them. More delays, other parts needed. Then the exhaust pipe had a slight dip in it and if I had not been doing the ceiling insulation / drywall myself and had sealed it up it would have been a huge huge problem because the dip was collecting condensate in a pool and blocking the exhaust flow. They also forgot the dust leg on the gas line so I had to get in reinspected. Didn't tell me I would need an outlet for the condensate pump and and and...

I wouldn't do anything with a fast schedule anyways because thats how you end up with mistakes and crapy work no matter what you are doing.

@ddawg16 - good to know. I have experienced some of this myself. The HVAC people although a total pain accidentally installed a super efficient furnace that cost twice what the one I payed for cost and once it was in they kind of just had to leave it.
 
#15 ·
Double check with your local building authority on how long a permit is good for. Some locations will leave it open indefinitely. Some have a 1 year limit. Some have a 1 year limit, with renewals possible. The variation is wide.

In our case, we had a 1 year limit, and they "forgot" to do the final. When we finished, a year later, we called for the final inspection and it surprised them that we slipped through the cracks. It should have cost us another $400 for the extension, but the head codes guy waived that and just went ahead and did our final.

That's an important consideration because of the added time of a self GC'd project. In the usual scheme of things, with a construction loan, added time is added money because of the extra interest. It's one of the reason that banks are very hesitant to work with owner builders. They don't want to get left holding the bag of a half constructed house that couldn't be sold to satisfy the loan amount.

You also want to check with your AHJ about what types of insurance that they might require for you to self GC, and if any type of training or classes might be needed. In some locations, that's the case. It's all location specific. You also want to purchase the latest version of the IRC and familiarize yourself with it. It's your bible for how things should be done, but it doesn't cover everything, and it doesn't cover what happens when things conflict.
 
#19 ·
My wife and I are in the very final stages of designing and building our house by ourselves. We're down to miscellaneous trim work, painting, and a little tiling. It is a log home we built from a kit. Because of that, we didn't need an architect - my wife designed the house using some software I bought her, and the log home company generated the blueprints and put together the kit. It included virtually everything to get the house dried in. Quite literally, almost the only thing we had to buy to get started was nails. Neither of us ever worked in any building trade; we're just very experienced DIYers.

Because we were more concerned with having the house be exactly what we wanted rather than the total cost, we didn't do much cost estimating or shopping around. If the wife wanted things like handmade wrought iron railings of her own design and a circular staircase not originally in the plans, she got them. Nor did we bother with competitive bids for the little work we subcontracted out (foundation, HVAC, and metal roof). Living in an area where homeowners can do just about everything themselves (subject to the same codes and inspections as the pros), that's what we did. Having owned nine previous houses, we have quite a bit of experience in electrical, plumbing, framing, flooring, etc., etc. We chose the few subs based on recommendations from contractors who are personal friends.

While it worked out for us, I don't recommend that the average non-professional build their house as we did. It is NOT an easy thing for just anybody to do. I was retired and my wife didn't work, so we had all the time in the world and essentially no day-to-day schedule. We had no children at home to worry about. We lived in our RV on the property the whole time so there were no additional living expenses or concerns about theft or vandalism. We had no debt whatsoever. Not counting time spent working with Habitat for Humanity, we had 35 years of DIY remodeling and construction experience. We already owned virtually all the tools we needed. And the budget wasn't a concern.

Are we glad we did it? Absolutely. Is the house perfect? No, of course not, but neither are the shoddy McMansions going up these days. Would we do it again? Yes, but we'd start a lot younger than we did.
 
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