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Community and Q&A

Building a new house: Planning stage

Jason Dennis | Posted in General Questions on

I’m planning to build a new home in Pender County, NC, near Burgaw. It’s in the southeastern part of the state near the coast. It’s in climate zone 3 and below the “warm-humid” line. Plain, super-simple rectangle, interior dimensions 39×50 (very open floorplan). Front door facing N (just slightly NE). Simple gable roof with the ridge running east to west. Wrap around porch across the front and down the east side. As you can imagine, I have so many questions, I’m not sure where to start. Regarding the foundation, I would like the house elevated as it would be with a crawl space, but I understand the issues / potential issues with building and sealing crawl spaces correctly. Would a raised slab be a good option? Do I understand correctly that the very basic idea is to build a block wall the size of the footprint, backfill it, compact it, and build the slab on top? What are the pros and cons of raising a slab like this? How high can it be raised? Also, what is the best method for insulating a raised slab? Rigid foam underneath? Finally, should I maintain this same thread for all questions about the entire project, or should I create a new thread for each question about a different aspect?

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Replies

  1. Scott Wilson | | #1

    Can you post the plan to show us your layout?

  2. Deleted | | #2

    Deleted

  3. Zephyr7 | | #3

    If you can swap your master bedroom closet and master bath onto the opposite sides of your master bedroom, you’ll put your master bath sharing a wall with your “regular” bathroom which will make your plumbing a bit simpler. If you can’t do that, at least make sure that there is NO PLUMBING IN EXTERIOR WALLS. This is important. Plumbing in exterior walls is asking for trouble, and is a bad idea even in warmer climates.

    If you’d originally thought about a crawlspace, why not just dig a little deeper and make it a full basement? It doesn’t cost terribly much more, but it gives you all of the advantages of a basement (space for building mechanicals, storage, etc). Unless you have a very high water table, I would definitely try for a full basement.

    I’d go with this thread for your getting started summary stuff, and then new threads for each specific question as you think of things. Really long single threads can be difficult to follow. Maybe try not to start a huge number of new threads all at once though, make it easy for our friendly moderators :-)

    Bill

    1. Jason Dennis | | #7

      Bill,

      I never really considered doing a crawlspace. I wanted to do a slab from the start, but I wanted the raised look of a crawlspace, hence my reason for asking about the raised slab. In regards to the full basement, it is in an area with very high water table and the excavation for a full basement isn't really an option.

  4. User avatar GBA Editor
    Martin Holladay | | #4

    Jason,
    For some reason, builders in North Carolina build foundation walls with concrete blocks (CMUs). Most of the rest of the United States switched to poured concrete decades ago. If you have a choice, select poured concrete over concrete blocks.

    It seems that you are talking about a frostwall-plus-slab foundation. For information on insulating this type of foundation, see this article: "Insulating a slab on grade."

    See the illustration below.

    1. Jason Dennis | | #9

      Martin,

      Here's a link showing what I had in mind.

      https://www.2x4designs.com/blogref/2016/3/7/foundations-crawlspace-vs-raised-slab

      The raised-slab detail drawing looks similar to what you posted, but possibly different? Your thoughts on this?

      The drawing has concrete blocks. So you believe that a raised slab like this should use poured concrete for the outer wall instead of blocks?

  5. User avatar GBA Editor
    Martin Holladay | | #5

    Jason,
    Thoughts on your floor plan:

    1. Your entry door is awkwardly located. Entering your house through a long, narrow, dark corridor is uninviting.

    2. Every house needs a minimum of two exterior doors for fire safety. So include another door.

    1. Trevor Chadwick | | #6

      Martin,
      It looks to me that there is a door in the top left (mud room) and one in the center bottom (the hall way)

      Jason,
      Up here in NY/ New England, everyone uses a poured foundation with full basement (8'+ walls) doing that would give you the ability to raise it as far as you would like, makes plumbing and electrical work much easier, and gives you a ton of room for storage, a now in vogue man cave, or anything else. All assuming the water table isn't too close tot he surface.

      1. User avatar GBA Editor
        Martin Holladay | | #16

        My apologies. In my hasty review, I missed the second door.

        1. Jason Dennis | | #19

          Martin,

          No worries. As always, your input is much appreciated. Do you have any thoughts on the "raised-slab" link that I posted? Potential issues? How to insulate?

    2. Jason Dennis | | #8

      Martin,

      The plan is something we are still actively working on, but we really like where we are on it currently. I like the idea of a foyer that is somewhat "separated." The foyer actually has a fair amount of space. It will be between about 5.5' from the doorway to wall that you are facing when you walk in. The wall creates a great spot for a painting and a small table. A lot of our initial ideas and sketches (with different and more open foyer placement) kept moving us away from a simple rectangle, which I wanted to maintain considering all the known benefits. So we were pretty happy when found a foyer layout that we liked that allowed us to maintain a rectangle envelope with the everything we wanted room and size wise. Also, that front hallway, past the foyer, will be fairly wide (at least 42" wide, maybe closer to 48") and only about 11' long. The window next to the front door will give the hall some natural light. Also, there will be a fair amount of glass across the back of the house that will also provide a lot of natural light. All that said, I'm definitely going to give your point some thought regarding the front entry.

      Trevor is correct that there is an exterior door leaving the laundry / mud room (top left corner). Also, there will be door(s) at the back leading out to deck/porch. That entire back wall is empty in the PDF I posted, but there will be several windows and at least a single door there near the kitchen/dining.

      Trevor,

      I agree with you on the benefits of the full basement. Unfortunately, the water table here will not allow it.

      1. Malcolm Taylor | | #10

        Jason,

        There is nothing stopping you from building a raised slab as you have described it. The concrete or block walls will need more reinforcing depending on how much higher than the existing grade they are. The footings need to be sufficiently below grade, not only to protect against freezing, but to allow your drains to exit the foundation.

        Intentionally raising the first floor is usually done to avoid flooding , or in areas with lots of snow, as usually people like to get their entry points as close to grade as they can to create an easy transition to their yards and surrounding landscape.

      2. User avatar GBA Editor
        Martin Holladay | | #17

        Jason,
        Sorry for my error; I didn't see the second door. So you're fine on that point.

    3. Vlad Shpurik | | #15

      Martin,
      I am curious about #2 item you've mentioned above. I suspect that the two door requirement may be subject to the overall floor area and/or number of rooms. The house I am building is under 1000 sq.ft. and has only one door. I do have an egress window though in each room.

      1. User avatar GBA Editor
        Martin Holladay | | #18

        Vlad,
        I'm not sure whether there is a code requirement for a second exterior door. (Any readers care to comment on this?) Whether or not a second door is required by code, it is common practice for fire safety reasons.

        1. Zephyr7 | | #20

          In commercial buildings, the code requirement is for the egress path to the nearest exit to not exceed a certain amount (150 feet if I’m remembering correctly). I’m not entirely sure that carries over directly to residential construction though, but if it does, the implication would be that very small houses would be ok with only one door. I’ve had to design in an extra exit before when the floorplan is such that the egress path is too long. This issue should be caught at plan review time when going through the permitting process.

          I do think it’s best practice to have at least two doors though, ideally on opposite sides of the house. Fire codes are all about “get out quick”, and if one door is blocked for any reason in an emergency, you’ll want that second door.

          Bill

        2. Brendan Albano | | #26

          R311.2 in IRC 2018 seems to says that a minimum of 1 egress door is required.

          R310.1 requires that every basement, habitable attic, and sleeping room have an operable emergency escape and rescue opening (i.e. an egress window)

          Certainly, small structures like ADUs are commonly designed and built with only a single egress door.

          Having two doors on the ground floor of a larger single-family home seems like a responsible and conservative decision as far as fire safety goes, but at a quick glance I'm not seeing a requirement in the IRC.

  6. Scott Wilson | | #11

    Jason, I would suggest you go to the library and check out some of the books from Sarah Susanka's series "The Not So Big House." In it she talks about "moving towards light" so if you're thinking about light from the windows in the great room brightening the front hall then you should place the front door directly centered on the front hall so that people entering will immediately see the light and want to move towards it (I also don't see a front hall closet).

    If your kitchen/dining/living space is on the south side then your master bedroom will be in the north east corner (which is fine) but you're placing a laundry/mudroom in the south east corner (which is prime real estate for morning sun). It would be better to bring the kitchen into the southeast corner so you get windows on that east wall letting light into the great room in the morning.

    In regards to the "two small bedrooms/common bathroom across the hall " layout, psychologically no one wants to cross a main entrance hallway after taking a shower in order to get back to their bedroom. It's too public a space.

    As to the front porch, it sounds like it's going to be pretty big if it's wrapped across the north side and down the east side. Those tend to be the least successful areas to add a porch since there won't be any sunlight on the north side and it isn't typical for people to be on a porch in the morning. Why not do a porch on the south and west side so people can use it in the afternoons and evenings?

    1. Jason Dennis | | #12

      Scott,

      Some of your points definitely have me thinking, so thank you for that :).

      In regards to the porch... I should have mentioned earlier that the property is going to be a small horse farm...just over 4 acres. I'm attaching a jpg of a very rough site plan with the house, detached garage, barn, and pasture. The area marked at the back west corner of the house is the approved spot for septic and leach field. The entire lot is wooded and the dotted line shows the tree line I intend to keep. Because of the placement we wanted for the house, the east porch made more sense, but I do understand your point about the west side.

      In regards to the back (south side), my wife definitely wants a covered deck/porch across a good portion of the back as well with room for outdoor dining, couch, swinging daybed, etc. I intend for the south wall to have a fair amount of glass and be the primary supply of natural light into the main room (kitchen/dining/living), and I am concerned that adding a large covered porch on the back will take away too much natural light from the house and make things way too dark. Your thoughts on this?

      Please feel free to share thoughts on the site plan as well, but the site for the leach field is pretty much set. It can move forward up to 25' feet or so, but cannot move any closer to the western property line. My preference would be not to move the house much closer to the road if possible.

      Thank you again for the input.

      1. Zephyr7 | | #21

        There are clear materials that you can use for your porch roof to allow more light in. Ameriluxe covelite is one option (clear or smoked polycarbonate or fiberglass roof panels). You can also use greenhouse polycarbonate glazing materials like twinwall (the insulating value won’t matter on an open porch, so you’re only looking at the structural properties).

        Regarding your comments about an amateur expressing their vision, I agree there is no reason you can’t do that. The problem many of us here that have been doing this for a while see is that while you may like what you see on paper, you may not like it so much when it becomes a 3 dimensional space. You may also find that things you thought would work well aren’t actually as good as you’d thought after you’ve been living in the house for a while. If you retain the services of a design professional, you gain the advantages of their experience to help you polish your design. I like to tell my consulting customers that my job is to make sure they don’t have problems 10, 15 years in the future and to avoid them thinking “I wish we’d xxxx”. I try to anticipate future needs and design for them. It’ll be worth it for you to at least have a professional do a design review of your plans. They may catch issues you never even thought of, and you want to fix any issues on paper before you begin construction.

        Bill

  7. Alan Lehman | | #13

    I have been enclosing crawl spaces and conditioning the air. I like to have the room to run ductwork and for any future issues with plumbing. I am using an ERV on my projects where I do this and supplementing with mechanical ventilation in the crawl space so I can keep my ERV cleaner. There is probably some cost savings possible with doing a slab on grade.

    I saw in the thread you are pretty happy with the layout. If that is the case and you are good with what you have ignore this post from here......That was fair warning.

    I am a design/build professional and I focus on small houses. Coming up with a really good working floor plan is not easy. What you have presented is more of a diagram than a good floor plan. I would strongly suggest you hire a design professional to help you with the house design. Yes, you could do it yourself and there are cheap or free CADD programs where you can make a drawing. But, designing a home that you will love living in takes more experience and vision than most amateurs possess.

    From what I have seen on the internet through CADD forums, in your neck of the woods you can probably get a great designer on board for less than 10k. Trust me, that will be 10k that will come back in returns paid by heading off potential problems and a better space that you will be living in for decades (more of less).

    1. Jason Dennis | | #14

      Alan,

      As I said before, the plan is still an active work in progress, but I do like where it is in general. I know that it's a rough "diagram" that is lacking detail and certainly needs refining, and I will likely be seeking out an architect for that very purpose. However, I don't feel that being an amateur or inexperienced in a field should stop someone from trying to express their own ideas and vision. I personally believe that doing so can only help to get you closer to what you really want when do finally seek the help of a professional. That said, your input is certainly understood and appreciated.

  8. User avatar
    Walter Ahlgrim | | #22

    How do you enter the pantry?
    Where will you put the water heater and furnace?
    I do not see any windows in the big room.
    Do you like the angled office wall?
    Is 4 acres enough for horses? I though 10 was the minimum but I am not a horse person.
    +1 on swapping the master bath and closet.
    I do not see much storage but I am a pack rat.

    Walta

    1. Jason Dennis | | #24

      Walter,

      I posted the layout reluctantly in a very rough, incomplete state. So to answer your questions...

      Pantry door would be on the wall facing the kitchen...likely a sliding barn door style.

      Water heater in the mud / utility room which can be made larger if necessary. My intention is to use mini-splits for heating/cooling.

      There will be larger windows (maybe 3?) across the south wall (back of the house) along with glass doors that open to a back porch.

      Personally I do like the angled office wall. I know that it cuts the size of the office, BUT it keeps the entry into the main room more open and I think balances the hallway entrance past the foyer in regards to space.

      My wife has raised horses almost her entire life. 4 acres, if laid out and managed properly is plenty of space for a small horse farm. I suppose at the end of the day it depends on how many horses you plan to keep. My intention is two and never more than three. Also, I don't intend for pasture to be the only source of food. So yes, plenty of space.

      I understand the point that was made about swapping the master bath and closet and it has been noted.

      I agree with you on the storage issue and that is something I'm currently thinking about. However, we are planning detached garage that will be heated and cooled with plans for a room above for storage. But honestly, my wife and I are not really "stuff" people. Our current house is fairly "empty." :)

      I'm going to attach another copy of the layout with some furniture so maybe folks can have a little better idea about what my intentions are in the large open area. I'll also add the intended doors and windows on the south wall. Please see post #2 above for layout attachments.

  9. Scott Wilson | | #23

    A house on a horse ranch definitely has different requirements compared to a standard home. Usually you need a lot more space for cleanup after being out with the animals and also more kitchen space for preparing, preserving and storing all that home grown food.

    You might have a look at this farmhouse design, which has been featured in several of Sarah Susanka's books (as well as numerous other articles on architecture). While it is a 2 story design it could be adapted to a one story plan. The main thing is to note how the public and private spaces are separated from each other and yet connected by passageways and views. The other thing is to see how the covered porch and screened-in porch are integrated into the plan.

    Also, notice how just about every single interior wall has been adapted to include storage, whether by built-in cabinetry, bookcases, closets or display spaces.

    https://architecturalhouseplans.com/product/field-of-dreams-farmhouse/

    1. Jason Dennis | | #25

      Scott,

      Thank you again for the insight. All very good points. Something else I should have mentioned before now...it's just me and my wife...no kids. However, we like to entertain a lot and intend on this house being a "hub" for the holidays and events for friends and family. Hence, the large open dining / living area, and the plans for an outdoor living area on the back porch.

      On the storage point, as I mentioned in my reply to Walter above, it's something that I am definitely thinking about. We do have plans for a heated / cooled detached garage with a room above for storage.

      Also, please note that I added two different copies of the layout to post #2. One has dimensions and the other has some furniture in the main room. Maybe they will help some folks understand my convoluted thought process a little better.

  10. Scott Wilson | | #27

    Jason, in looking at your updated plans the problems with the layout become more apparent.. The front entry hall is too small and far away from the great room. The two small bedrooms only have room for a bed and two night tables. The area around the dining table is a bit cramped and you have a major circulation pathway coming through the kitchen from the mudroom.

    If you have a look at this floor plan I think the vast majority of the layout problems in your plan could be solved by moving the entrance hall to the side and running the bedrooms across the north side of the house. This plan is a bit smaller than your design but you could lengthen the house by adding the mudroom/pantry you want on the other side of the exterior kitchen wall and then widening the bedrooms to keep the house a rectangle

    One thing you mention is that your house is for 2 people. Although you do want some extra bedrooms for guests you might consider doing what this plan has done and make one of the rooms an office/bedroom by using a Murphy bed.

    https://www.familyhomeplans.com/house-plan-74001

    1. Jason Dennis | | #28

      Scott,

      We have thought about a office/bedroom, which is what I have currently, but the consensus was for a separate office area (read that as wife made executive decision... :))...

      I'm not trying to defend the flaws of the plan, as there are plenty, but I think that the drawing may not be easy to see the spacing on. Actually the guest rooms are sized to handle a night stand an a chest-of-drawers, likely all I would ever need there. Also, assuming a 10' x 4' dining table (to seat 10 comfortably), in the current layout you could provide 4' of space from the table to closest obstruction, which by most standards that I've seen is considered at least somewhat spacious around a dining table. Also that is a point where just a few inches can make a tremendous difference. Size of furniture would be everything in this case. That said, your points are certainly noted.

      I've thought about the balance left to right and moving the bedrooms across the north side of the house just as you mentioned, but I've felt like the front door being off-center on the exterior was too "jolting" when you see it. It's just very unsettling to me for some reason, especially if you are considering a front porch.

      In regards to the front hallway...it's something I've really thought about. I like the idea of a "separated" foyer and a "path" leading to the main room, but I have felt like it might be to narrow at 42". Is there a width that you think would make it more workable in your opinion? 48"? 52"? Wide enough that it feels more like part of the foyer than it does a hallway?

  11. Zephyr7 | | #29

    If you have no way to avoid a narrow hallway or the occasional smaller than ideal room, you can often make those spaces seem larger if you can raise the ceiling. I don’t know if that’s an option for your particular house design or not, but it might be something to think about. Another thing that can help in tight spaces are pocket doors since those eliminate the need to keep the door swing area clear.

    Bill

  12. Scott Wilson | | #30

    If you are set on a separate office the three bedrooms in the second plan I posted could be slid up and an office located where their den/bedroom is. As to the front door, on the same plan it could be centered on the wall between the living room and office location as well but I think by choosing a "path" to the great room from the front entry you are negating the prime function of the front entry which is to create a "sense of arrival" in the home.

    When guests arrive they look forward to seeing into a grand space, wondering what else awaits them and being intrigued. To arrive in a small separate room with a closet or maybe a bench and then have to travel down a narrow hallway is a bit of a disappointment. However, such a design is more than adequate for a rear mudroom entrance (and is actually preferred since most of the mess caused from arriving with groceries or wet clothing is hidden away). That's why I suggested having the front entry more "open" and closer to the great room.

    The main thing to be gained from the second plan I posted is the separation of the house into public, semi-public and private zones. The main entertaining spaces are all in the great room, the bathrooms are in the middle and the bedroom are separate and private.

  13. David Pilati | | #31

    How important is insulating the slab in your area?
    I did in Raleigh but partly as a comfort thing. The ground will cool the house in the summer so it is my understanding that you lose that in exchange for the winter effect. As you get warmer, the value of the slab insulation decreases.
    How far are you from water? Rivers/ponds. I am sure the generous rain lately has kept you thinking about that. I built on a raised slab but we are a high point compared to neighbors and the street. No body of water nearby.
    I checked and Burgaw is 46 feet above sea level but the potential for flooding is generally quite significant east of 95. Raleigh feels high at 450.

    1. Jason Dennis | | #32

      David,

      I'm not in the area of Burgaw that is near the Cape Fear River and prone to flooding. As a matter of fact our property and a good amount around it did NOT hold water at all after Florence. There is a small creek that runs along the back of the property that I imagine gives water / run off somewhere to go. So yes, there is a potential for flooding in the general area but our "micro-area" faired very well through Florence, which is probably a good indicator.

      Jason

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