House addition questions

[Alexander Galkin]

I am planning an addition to my 2 story colonial. The addition is actually extending first floor along the side facing backyard. The addition will be

50 ft long by 6 ft wide. I want to do as much as I can myself leaving to pro only that part of the job that I absolutely cannot do or make no sense to do myself. I have moderate experience in framing, plumbing, electrical, insulation, drywalling and have all necessary power tools to do the job. I do not have any experience in building foundation or putting joist-beam floor system. I am weighing two options for the addition foundation: crawl space and full basement. Here I have several questions:

1. While I realize that every project has it many specifics what the approximate cost would be to excavate hole for the 50 ft x 6X ft addition foundation, build the foundation walls and slab, backfill and put the floor with no subfloor? I line in Central NJ.

2. What's the approximate cost difference of building full basement vs. crawl space? Frost line in my area is 3 ft so trenches for the footings must be dug 3 ft at least.

1. What's the approximate cost and benefits difference of concrete monolithic vs.cinder blocks foundation? My house (55 years old) foundation is built using cinder block with I believe no rebar reinforcement.

2. Is it feasible both economically and from time perspective trying to do some of foundation work myself? Could you advise me if any of the following foundation tasks I can do myself or I should forget about them and leave them to pro:

- building footing forms and put rebar in them

- renting gas powered concrete mixer or get ready mixed concrete and build footings myself

- building foundation walls using cinder blocks

Is above what I can really do myself or it is not worth it? I have limited experience with concrete (redoing parts of basement slab after installing underslab plumbing)

I believe having foundation built and floor put I can take over enlisting my Dad's and friend's help to put frame, siding, roof, plumbing, electrical and internal finish.

Any comments and advise would be greatly appreciated.

[Edwin Pawlowski]

For any quantity of concrete don't even think about mixing it yourself. It is not just the backbreaking work, it is the quality, consistancy, and time do do it in batches when a pour should be continuous.

There are alternatives to block and the usual plywood form. Look into using insulating concrete forms (ICFs) for at least he foundation if nt for the entire wall. It can be done yourself. Check out

Be sure to get up to speed on all the newer engineered wood products available. Not to mention al hte ohter building materials that simplify building. Ed

[Lyle B. Harwood]

? Is above what I can really do myself or it is not worth it?

If your time has value, you will be ahead to hire pros.

If your time has no value, how will you pay for materials?

In any case, the first thing you need is a design, from a licensed, local architect.

Best of luck, and let us know how it comes out!

[Tony Hwang]

Hi,

6 feet wide? That is really narrow! Would feel like tunnel. Tony

[Jeff Smith]

First thing to check is if you can submit the plans for the addition yourself (many states allow this under an owner builder provision) or if you're required to have an architect or contractor stamp them. Unless you are in the sticks you probably will be required to have a structural engineer look over and stamp your plans. Also if you're putting in any electrical (probably are) you need to see if based upon the size of your addition, if you will trigger redoing the smoke detectors in your main house as they are probably not all interwired together with building power and battery backup. If you are adding over a certain % of space onto your house usually you have to retrofit the smoke detectors in the entire building.

You're going to have to talk to local subcontractors to get their rates, they vary widely. Typically excavators charge by the hour.

Concrete and steel in most areas of the country has gone up considerably (steel 3x) in the past year and so the cost difference is probably more than you would expect.

My guess is, if the building codes are anything like in Nevada, you're basically going to build what the structural engineer tells you to build, unless you want to "upgrade" beyond what the engineer requires.

I definitely wouldn't be mixing concrete myself, that's not worth hassle, but you may be able to build footing forms and rebar, but the issue is you better be able to lay the forms out completely square and level. Most contractors are using laser levels for this nowdays and not the cheap $50 ones from sears.

[Alexander Galkin]

[Alexander Galkin]

I know I need a licensed architect to calculate the load, size and type of headers, etc. I already talked briefly to an architect and also to a building inspector while he was inspecting my other project. So when I will be applying for a permit I will have my plans reviewed and sealed by architect. Regarding electrical I have new 150 A service panel in my house and I will be completely upgrading wiring in kitchen, bath and office that the addition extends. It does not add any separate rooms so I don't think I need more smoke and CO detectors then I already have. They all but one in basement and battery powered and not interconnected. Fire inspection was passed OK.

[Tom Baker]

That's a lot of work for an extra six feet! Have you checked with zoning and the building department? Have you worked out the structural requirements for openings in the existing wall? Is there room to move equipment from the street to the back of the house? Is there enough vertical distance to fit a roof below the second story window sills? Do the existing mechanical & electrical systems have capacity for the addition? If the existing basement wall is unreinforced, how is the new wall to be tied to it?

The cost of excavation has to include digging next to an existing unreinforced wall without colapsing it; excavating one large enough to accomodate working room and the angle of repose of the earch; disposing of the extra earth.

There is more that needs to be taken into account before begining and the cost to design the work will be no less than for a much larger addition, since there are some things that must always be done.

Tom Baker

[Alexander Galkin]

My time does have value. And although I earned 3 times more then an average tradesmen annually their per hour rate (this is what actually you are paying them) exceeds probably that of some CEOs. In area where I live it is just astronomical. Initially I wanted to hire a contractor to install a sewage ejector pump and change plumbing in my basement when I was building a basement bath. I called several plumbers to get quotes. One said that job was too tough and refused even to consider it. Other gave quotes around $5500. I was shocked. Finally, having no prior plumbing experience but very good understanding what and how to do I did everything myself in three days. I did though made one mistake found by a plumbing inspector and that took me one more day to correct. cost of material was about $200. Besides obvious economic benefits of doing myself there are two others that other people my not share. First I really like building, I enjoy it. Second I hate so much to deal with contractors. I had very little experience with contractors and almost all of it is negative. I would rather learn to do and then do something myself then spend time calling several tradesmen, collecting quotes, bargaining with them, supervising them, etc.

[Alexander Galkin]

First of all thank you for your response.

See below my answers to your questions.

I need six feet to extend kitchen and office. I don't need anything more as I don't want to reduce my backyard by building larger addition.

No I have not applied for a permit yet and my project is in early planning stage. That's why I posted my questions here. Depending on what part of it I will be doing myself I will plan and budget accordingly. I did though speak to a building inspector while he was inspecting my other project. I don't beleive zoning department will have any issues with my plans.

Not yet. I plan to consult and get my plans signed by a lisensed architect before applying for a permit.

I can remove part of the fence that separates back yard from front yard to allow excavator and other equiptment and materials to be moved from driveway to backyard working site. At the same time I want all job to be done as carefully as possible. I don't want entire backyard to be turned upside down. Especially I worry about centures old oaks on my backyard. Although all trees are not in close proximity to the potential building zone I don't want to take chances. Do you have some advise what I should do to make as little damage to backyard as possible? I have no idea what type of excavator is needed. I also don't know how concrete is delivered and poured for the footings. I know there are concrete deliveries with pump that allow to pump concrete for the structure on backyard while truck is standing on driveway. But since that amount of concrete for the footings is relatively small hiring a concrete pump truck might be very expensive. That's why I asked it if it feasible to rent gas powered concrete mixer (my local HD has one). I can then have coarse aggregate, cement and sand deliverd and dumped on driveway. I also leaning to building walls using cinder blocks as they also can be dumped on driveway and I can move them to the work site later.

Yes. Actually, the shed roof I am palnning will have the same pitch as my house roof for the six foot wall extension.

I don't understand what "mechanical" means. I do intend to replace all wiring for the kitchen, bath and office that will be extended. The bath will also be completely renovated and its plumbing will be fully replaced.

I talked to a building inpector and also read in books. Holes will be driled in existing foundation and rebar will be inserted in to them where addition foundation attaches to existing foundation. I do plan to rebar reinforce footings and foundation walls regardles of how they will be built. I also plan to waterproof the addition foundation if it will have full basement but I didn't think yet on waterproofing method.

I understand that. Excavating will be done by a pro.

[Bob Morrison]

In most states this is illegal. Most states require the plans to be prepared under the "direct supervision" of the design professional. Direct supervision is usually defined as "in the design professional's office".

[lazenby]

One important ingredient was left out of your original post, Alexander:

Why would you (or most anyone else) want a six-foot wide by fifty-foot long basement, whether cost effective vs crawl space or not? That is really the basis of your problem.

Off hand, I'd say, it might be good for coal storage (if you ever have a use for that much, if any, coal) or a very narrow, indoor lap pool (for lapping underwater) or maybe a cistern or root cellar . . . but now I'm getting too practical to be plain silly. Off hand, I'd go with a crawl space, just because the basement isn't likely to be cost effective regardless of the likely usefulness.

Jim

[Alexander Galkin]

I want to build a sauna in the additional basement space. 6 ft wide is enough for that.

[lazenby]

Fifty feet long! I wasn't being silly after all. A sauna lap pool.

Saunas are a good thing! Why not put it on the grade level addition? No need to hide it.

Jim

[Alexander Galkin]

[Edwin Pawlowski]

But the basement is right nest to the existing basement. I'vd love to have the extra 300 sq. ft. of storage! Cut the existing foundation for access. Not a big deal in the scheme of things.

[willshak]

On 12/4/2004 12:16 PM US(ET), lazenby took fingers to keys, and typed the following:

I could use a 6' extension on my basement. It seems we accumulate more 'stuff' than we get rid of, therefore, additional storage space is always welcome. Where I live, the footings have to be 48" deep. Another 48" added on is no big deal.

[B]

I didn't read every word of every reply, but let me add that it will be difficult to divvy up jobs and sub-jobs between yourself and a contractor because a contractor usually doesn't want to take over from a DIYer and for good reason, and often doesn't want to take over from another contractor. So, what you CAN do yourself still might not be practical.

-B (contractor who has been burned by taking over somebody else's mess)

[Bob Morrison]

Alexander:

I don't know what state you are located in, but the building inspector is not the last word on this issue. In fact, most don't know enough about the state licensing laws and minimum design procedures to put in a teacup. Ever heard of trying to do a "lateral analyst of one wall of new addition". Patently ridiculous! Yet, that was the comment from the building inspector.

I would NEVER put my seal on a set of drawings prepared by the owner. That's a good way to lose one's license.

[Alexander Galkin]

I am not going to build 50 ft long sauna. I plan to build sauna in part of new basement space if the cost of building basement is not considerably higher then building a crawl space. 6 ft wide is enough for sauna I want to build. I have now problem using rest of the space for storage.