House Addition Cost

[brendon444]

What would I be looking at to add a 16’ wide by 14’ deep addition on a house built in 2008. Thinking it will be on a grade beam foundation with a crawl space and used as a bedroom. Will possibly add a ensuite depending on cost and if we can fit it into this space.

Looking for ideas and how I should go about this project. Had a builder come out today and gave him our house drawing and he is going to give an estimate. I am not sure what a fair price would be with or without a bathroom. Hvac and plumbing seem to be close by.

Any suggestions on what and what not to do?


Attached picture of house where addition will go. Thinking of stepping down the roof line and going with the same pitch roof. Just underneath upstairs window


Open to any suggestions.

[EZM]

Originally Posted by brendon444

What would I be looking at to add a 16’ wide by 14’ deep addition on a house built in 2008. Thinking it will be on a grade beam foundation with a crawl space and used as a bedroom. Will possibly add a ensuite depending on cost and if we can fit it into this space.

Looking for ideas and how I should go about this project. Had a builder come out today and gave him our house drawing and he is going to give an estimate. I am not sure what a fair price would be with or without a bathroom. Hvac and plumbing seem to be close by.

Any suggestions on what and what not to do?


Attached picture of house where addition will go. Thinking of stepping down the roof line and going with the same pitch roof. Just underneath upstairs window


Open to any suggestions.

Be careful to ask about proper insulation for the plumbing if you choose to add the bathroom. Many of these crawls are built with the crawl as a cool space (sun rooms, 3 season rooms, boot rooms, etc..)

This is the more cost effective way.

If the intent is to use a grade beam and cold crawl, and you must have a bathroom, I'd locate it closest to the house so you get a decent pitch on the toilet drain and get it back into the plumbing stack back into the house using shortest possible route - and build a warm box around it to keep it a warm space.

I would also cost in radiant floor heat into that space and insulate very well from below using reflective type insulation/vapour barrier.

I can't tell you how many "cheap" additions have ended up being a nightmare for the home owners.

It looks like your grade outside will require your crawl (floor) to be potentially below grade - so make sure they take the appropriate measures if it's a cold/wet space - mold and lack of cool air circulation in short or below grade crawls can be ugly.

I'd let the contractor chime in on prices - but if you have enough electrical available, capacity on your furnaces, etc... you are probably well into the $100K range on something like this to be realistic (and to get it done properly) so it doesn't look like a "me too" patch job.

Having said all of that - if you can make the crawl into a warm space you might be far better off.

[brendon444]

Yes I want it to be seamless and look like it was part of the original house or I am not getting it done. The floor will be the same level as the deck so 4ft off the ground.
Was thinking the crawl space walls will be insulated and insulate the ground some how whether it be pouring a small pad with insulation underneath or somehow insulating and sealing the ground and adding heat duct to this area. . Or do I spray foam floor joists?


Have the electrical and furnace capacity. Will not be adding any type of floor heat for only 225 sq ft. If my basement already had it I would tie it in but doesn’t seem cost effective for 225 sq ft.

[bobalong]

I would be curious what your estimate is. I am just in the process of estimating a 14x14 addition similar to yours except the floor will only be about a foot off the ground. My son and I will be doing all the electrical and carpentry ourselves. Not going to bother with in floor heating or plumbing from the house as it is just an entry. Going to insulate roof, walls and the floor well and just use space or gas heater.

[Trochu]

Just for clarity, a grade beam typically implies a a reinforced concrete*beam*that transmits the load from a bearing wall on to a spaced foundations such as piles. I'm assuming your think of utilizing a foundation/footing wall which is a reinforced concrete wall that transmits the load from a bearing wall to a continuous foundation such as a footing.

[brendon444]

Originally Posted by Trochu

Just for clarity, a grade beam typically implies a a reinforced concrete*beam*that transmits the load from a bearing wall on to a spaced foundations such as piles. I'm assuming your think of utilizing a foundation/footing wall which is a reinforced concrete wall that transmits the load from a bearing wall to a continuous foundation such as a footing.

I understand the difference, I thought I would need concrete piles. I’m not sure what our county code calls for. I just want this done correctly if I go ahead with the project. So if one type is a better choice over the other that is what I will lean towards.

[Ronji]

In our company, we exclusively use engineered screw piles. Our grade beams are then formed with ICF. We have used this method for years and works well.
If you have any questions, pm me and I can discuss with you over the phone if you like. We have done a ton of additions.

[mmhmmmm]

Where are you located approximately? Sounds like your on the right track. Grade beam on piles, insulated walls around the outside similar to a basement, with a “mud slab” essentially less finished concrete with 1.5-2” insulation underneath. Add some heat runs into crawl space and good to go. Tricky parts are siding and roof tie ins to look original.


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[Ken07AOVette]

what about extending the basement under the addition, which would double your usable added space without any additional taxes? Cut a door through the existing basement wall, and you then have heat under the new space too? Yes i know it will cost more, but just a thought?

[brendon444]

Originally Posted by mmhmmmm

Where are you located approximately? Sounds like your on the right track. Grade beam on piles, insulated walls around the outside similar to a basement, with a “mud slab” essentially less finished concrete with 1.5-2” insulation underneath. Add some heat runs into crawl space and good to go. Tricky parts are siding and roof tie ins to look original.


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Yes that how I was thinking of doing it.
I don’t need the extra space in the basement and don’t want to dig down that far.

With the roof line if you look at my picture I was thinking of stepping the roof down below the window and running at the same pitch as the roof beside it.
Or should I move the window and just continue the roof line over.

[brendon444]

Any suggestions what to do with roof? Want it to look like it belongs

[brendon444]

Originally Posted by brendon444

Any suggestions what to do with roof? Want it to look like it belongs

Located in lloydminster I forgot to add.

[skoalzie]

What is the window above for? Stairwell? Bedroom? Master bedroom?


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[JB_AOL]

Nothing to add, except, get a proper HVAC quote or sizing done for your existing system. I know with my house, if I added 50sqft, I would require two furnaces.

[brendon444]

Originally Posted by skoalzie

What is the window above for? Stairwell? Bedroom? Master bedroom?


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Master bedroom bathroom. Just to let in light as it is opaque and can’t see through. I think if we do the project we will move the window and carry the roof line across as this will look the most natural and like it is not an addition.

Got a quote back at $65,000. Seems to high for only 225 sq ft on a crawl space.

Also, when drilling for concrete piles is there a way to effectively locate septic lines. They exit that half of the house and would want to be sure not to hit them. Drawings don’t show enough detail.

[mmhmmmm]

Locating lines shouldn’t be too hard. Approx 500 dollar job in the city of Edmonton I think. Typically have them located along with all water gas and electrical lines. They can send a probe down the line from inside the house to get it pretty precise. Pile layout can be altered to suit the sewer line location. 65k sounds fairly in line imo. If the bathroom is included in that I think it’s fair for sure. Relocating window hopefully won’t be hard, but depends where the header is located above it. I agree with moving it up for the roofline to come across. But might be right for room. Worth converting to a shorter window if need be.
Is the 65 including bathroom, window relocation, and all other work? Concrete slab in the crawl space is a nice touch as well if that’s included


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[brendon444]

Decided not to do bathroom based on limited space.

Quote did not include moving window or concrete in crawl space. Just included lower pitched roof underneath the window.

I like the idea of sending locator down the line seems the most accurate.

Would like to move the window and carry the roof line over. Just build a bedroom with no bathroom on a crawl space with concrete slab. My budget is 30-40k is this reasonable? 225 sq ft and essentially 2 walls.

[skoalzie]

My thought was if it was in the master maybe you could turn the roof of the addition into a deck which could be nice off the master. Maybe not the way to go if you would always have to walk through the bathroom. Does seem a bit steep on price though. But there is a lot of work they have to do there!


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[koothunter]

I'm just finishing up a 1080 square foot addition with 1 full bath, a half bath, and a vaulted ceiling. I did most of the work on my own and I'm only into it for $60,000 max. I also live in BC where everything costs more and has 12% tax. The $60g includes everything from excavation work to décor. I have some exterior work left, but not much.

DIY and learn a few skills while your at it. Saves tons of money and is actually quite enjoyable. I did it over the course of 2 years while working 14 hr days at 2 other jobs.