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Community and Q&A

Unfinished Spaces for Improved Building Envelope

cococchio | Posted in General Questions on

Due to budget limitations, I am considering leaving the 2nd floor and basement unfinished rather than cheap out on the house shell. The builder I am working with is advising against it “as this will complicate the remainder of the project”. To me this does not make much sense and it sounds like the builder is just trying to maximize its profit.
Any thought about this? Thanks!

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  1. user-6623302 | | #1

    Please explain what you mean by unfinished.

    1. cococchio | | #7

      As much as possible. Walta in his answer below gave me precious infos.

  2. walta100 | | #2

    I think second floor plumbing ruff in, electrical will need to be finished, HVAC ruffed in, insulation and air sealing and drywall are required before you could get an occupancy permit and make sense even if no permit is required.

    Unfinised basement is normal enough.


    1. cococchio | | #8

      Thank you!
      So would plumbing ruff in, electrical, HVAC ruffed in, insulation and air sealing and drywall also required (or make sense) also for basement?

  3. DC_Contrarian | | #3

    How far along are you in the construction process? If you're in the planning stage it might make sense. If the house is already framed and dried in the contractor may have a point. He should have already booked the trades and drywaller. Asking for revisions at this point isn't going to save a lot of money.

    1. cococchio | | #9

      Still at a planning phase and feasibility study. Unfortunately, we have a design service agreement with the builder so we cannot just pick another builder without hiring another architect. However, if the builder does not allow unfinished 2nd floor I will not proceed with them. The construction cost increased by 25% c0mpared to the target price.

  4. Expert Member


    Under our code there really is no "unfinished". By the time you put in what is required for final occupancy, what is left is incidental. You should see what is needed where you are.

    1. cococchio | | #10

      Yes that's something I need to find out

    2. DC_Contrarian | | #13

      I think you could revise the permits to have an attic storage space and basement that would require a lot less than if they were finished as bedrooms. What I see as more of an issue is if you have construction financing, the bank is going to want to see any permit revisions. And if you got financing based on say a four bedroom, 3.5 baths and now you want to build a one bedroom, 1.5 baths they're going to balk.

      1. cococchio | | #17

        Thank you! I did not apply for permits yet but I am applying for a construction to perm loan. The lot is fully paid for and I can put down over 50% of the construction cost so hopefully the bank will be ok with such a plan.

  5. Expert Member
    Michael Maines | | #5

    It depends on what you mean by unfinished, and also what climate zone you are in. If it's a heating-dominated climate, you don't want uninsulated walls, or insulated walls that are open to absorbing water vapor from the interior.

    1. cococchio | | #11

      I am in zone 4a. Definitely I would install insulation and seal the envelope.

  6. seabornman | | #6

    You could treat the second floor as "attic" which means you could leave all plumbing and electrical out, however in order to meet energy code you'd have to either insulated the floor to code levels, or insulate the complete second floor and remove portions when it comes time to put in electrical and plumbing. HVAC could be a separate unit or a blocked off supply duct. It could be done.

    1. cococchio | | #12

      Yes thank you! That's what I was hoping to do. I would insulate and seal the entire building but install a second HVAC unit or connect a supply duct later on. I guess I just need to check the specific regulations in my county.

  7. Deleted | | #14


  8. DC_Contrarian | | #15

    If you plan is to finish the house now with the second floor and basement unfinished, it would make sense to do the following:

    Rough plumbing

    These are things that you either have to have to pass final, or will be a lot more expensive to do separately later. The big thing is drywall, which you need as an air barrier.

    You could omit the following:

    Bath fixtures
    Bath cabinets and counters
    Bath flooring and finishes
    Interior doors
    Interior trim
    Finish flooring
    Interior painting

    Those six items aren't nothing but they may not be much in the scheme of things. Certainly not the 25% savings you're looking for. And it will be more expensive to have it done later. For example, new houses now are mostly spray painted, if you do that before the rest of the finish the labor to do a few more rooms is pretty minimal.

    1. cococchio | | #18

      I am a bit confused. If I apply for permits in which the 2nd floor is an attic storage space, do I still need to do HVAC, electrical, rough plumbing and drywall? Can I have plumbing if the permits do not show any bathroom in the plans?
      I understand that delaying these things to a later time in principle might cost more, but on the other side I will be able to shop around and compare multiple quotes whereas right now builders are still very busy and it is so hard to find contractors with decent quality/cost.

      1. DC_Contrarian | | #21

        I'm assuming the plan is to finish the space as time and money allow. Absolutely the most expensive thing to do is to build the space as unconditioned, unfinished space and then later try to convert it to conditioned, finished space. That's essentially building a small house and later expanding it to a bigger house. You're much better off doing it as conditioned space even if it's unfinished.

        Conditioned space needs an air barrier. In most houses the drywall is the air sealing layer. Depending on your insulation choice and local regulations you may need to cover your insulation as well. So the simplest thing is to put the drywall up, it will also be relatively inexpensive to do when the drywall crew is there. When it comes time to finish the space you don't want to tear down the drywall, so you want to do the stuff that goes behind the drywall -- electrical and plumbing. The electrical requirements for lighting and outlets are less for unfinished space than for inhabited space, but you should run the wires you're going to need. If you don't want to put fixtures in you can cap the junction boxes.

        Plumbing is going to depend on what your locality allows. Where I am, they won't let you stub out a bathroom without a permit, and you have to finish it to close out the permit. The reason is they are worried (with good reason) that people will finish the bathroom on their own once the inspector is gone. I've even heard of the city questioning utility sinks that were in unlikely places, suspecting that once the inspector was gone that utility sink would turn into a bathroom. But you should be able to run pipes through the wall to the bathroom. There you'll have to take up the floor and open the walls when it's time to finish.

        You're going to have to do HVAC because this space is part of the conditioned envelope of the house, if it's not conditioned the rest of the house isn't going to be comfortable.

        1. cococchio | | #23

          Thank you very much DC_Contrarian for your detailed answer. This is all very good information I will use tomorrow when I discuss with the builder. I will provide an update soon.

  9. seabornman | | #16

    Present a specific plan to the codes office and see what they say. You'll have to plan ahead. For instance, you'll want to put a vent through the roof for future plumbing, but you'll have to cap it off.

    1. cococchio | | #19

      The connection for future plumbing would be between 1st and 2nd floor, right? . Why would I need a vent trough the roof for future plumbing?

      1. seabornman | | #20

        You will need at least one plumbing vent through the roof for any plumbing on the first floor. You may need other vents for second floor plumbing. Better to put them in when the roof goes on.

        1. cococchio | | #22

          oh ok good point, thank you so much!

  10. cococchio | | #24

    Thank you all for your comments and suggestions! Just a quick update. The builder accepted to quote a second floor with only Windows, Electrical, Rough plumbing, HVAC, Insulation, Drywall but I am waiting from my lender to be sure there is no problem with financing.

    Now the builder mentioned today that if we leave the basement unfinished I would have one or 2 vents from the HVAC in the basement, 4-6 bulb lights and only sewage pipes roughed in. Also the wall insulation would be blanket insulation instead than glass batt because there will be no framing.

    Would make sense to have Electrical, Rough plumbing, HVAC, Drywall also in the basement or should I just wait and do all electrical, rough plumbing and drywall for the basement AND 2nd floor at the same time when I have the budget for it? Thank you!

    1. DC_Contrarian | | #25

      What is your long-term plan for the basement? Is it to finish it as time and money allow? If so I think this is a plan. The only thing I would worry about is the HVAC. The heating and cooling load for an unfinished basement should be the same as for a finished basement. So you should have the same duct capacity. I guess if it's an open space you could just have a trunk that dumps out into one vent, and then later extend that trunk and split it when you break the space into rooms.

      1. cococchio | | #26

        Excellent thanks. Yes the idea is to finish the basement when we are a bit more "financially confident" . With a second baby arriving soon I need to keep some buffer 😊

  11. cococchio | | #27

    I talked to the lender: the unfinished space (basement) or semi-finished space (2nd floor) does not contribute to the appraised value of the house.
    I can take my chances and apply for an appraisal anyway ($800).
    If the appraisal come back too low (likely) I then have to options:
    1. Finish at least few rooms on the 2nd floor to increase the appraisal value (not my favorite option because I would need to install very cheap finishes and most likely replace them later on).
    2. leave the second floor unfinished (i.e., no drywall, electrical, plumbing). For the HVAC, I would either leave one or two vents and complete ducts later on (as suggested by DC_Contrarion for the basement) OR to not install HVAC at all and install a second heat pump unit later on. The energy model of the house indicates that a 5.5 ton would be required to heat the house (basement, 1st and 2nd floor) during winter. If I want to use a single 5 ton VRF heat pump I would need to install extra insulation (replacing zip with zip R 2 inch, extra insulation in the unconditioned attic) and have dumpers for zoning. The rater energy model did not show much of a benefit in terms of energy savings, however, extra insulation would allow to save the extra cost associated with a second VRF heat pump. The cost of an extra heat pump is probably close to the cost of dampers and oversized ducts so not sure this is a strong point.
    On the other side, one heat pump it also means we could use a single ERV for the entire house in hybrid configuration, with significant savings AND less filters, maintenance to take care of.

    As you can see I am a bit overwhelmed by the options.
    Any suggestions would be much appreciated, thank you!!!

    1. DC_Contrarian | | #29

      I'm not at all surprised that the unfinished space doesn't contribute to the appraisal. Appraisers have a formula they use, it may vary regionally but it's generally some combination of number of bedrooms and bathrooms, finished square footage in combination for neighborhood averages for those.

      I wouldn't expect that leaving the space unfinished like that would change the energy usage of the house at all.

      I suspect you're going to find that finishing the second floor cheaply makes the most financial sense.

  12. malady | | #28

    I realize this is probably far from your original vision for the project , but what if you built a two bedroom home which you could add a wing to later? You could design the ultimate plan now and build it in two distinct phases. Practically speaking, you would be forced into a one story home absent significant rebuilding of the first phase.

    1. cococchio | | #30

      Redesigning would add extra cost / time that’s why I would rather leave the 2nd floor unfinished but I might need to do that if there is no financial solution

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