I have a single-story home in Austin, Texas with a huge attic built using Engineering Roof Truss System. I want to do an attic conversion to have at least 1500 sq. ft. of living space in my attic.

Here's a video tour of my attic - https://youtu.be/ri5QBykX-nw

Primarily, I'm interested in learning the feasibility, best solution and a cost estimate for reframing the truss in my attic for an attic conversion. Please provide explicit details.

Other challenges for attic conversion include relocating the HVAC unit in the attic and having a strategy for plumbing so I can have a bathroom in the converted attic. Please comment on the best strategy for them.

  • 2
    You will need a structural engineer to even think of changing the roof trusses. The engineer is needed to design how that roof will be change, including how the trusses can be remove and support the roof at the same time. Your insurance will insist on it being done this way. Might be cheaper to just addon to the house instead of changing the roof.
    – crip659
    Oct 13, 2021 at 0:03
  • 2
    Pricing is always off limits, but think of this as a renovation where you remove the existing roof and add a second floor. So you're basically building a one storey house on top of your existing house. Hint: not cheap. Oct 13, 2021 at 3:50
  • I'm not interested in discarding or lifting the roof for a second floor. I want to do an attic conversion so it's becomes sort of 1 1/2 story home. Oct 13, 2021 at 17:28
  • 1
    I don't think that's feasible given your current roof structure.
    – SteveSh
    Oct 13, 2021 at 20:32
  • What's the span in the direction the roof trusses run? 30', assuming they span two rooms?
    – SteveSh
    Oct 13, 2021 at 20:33

1 Answer 1


That could have been a great second floor if it was framed that way. With the high pitch roof you have, it had high potential. In my opinion, you will be better off removing the whole roof system and reframing it from scratch. The way the trusses are configured with a 2X4 bottom cord, the restructuring needs to start from the ceiling of the original floor, up from there. In addition, to re-support the roof from the underside would be a massive undertaking.

And yes an engineered would definitely be involved, nobody on this forum would be able to recommend anything in the way of a relocation of this or that, in my opinion, since the whole attic needs to start over. Then things like that can go in the attic of the second floor, even though all of it is still under the roof.

It would be considered a 1 1/2 or 1 3/4 story home.

  • I will be getting a home improvement/remodeling company to take this project, so far very few remodeling companies in Austin, TX have an idea how to restructure the framing for attic conversion. They want me to invest $3-5K for design documents to check the feasibility. My concern is I'm paying a huge amount for a problem they may not solve it or solve ineffectively and offer me an an exorbitant quote. Oct 13, 2021 at 18:28
  • 3
    You misunderestimate how exorbitantly expensive trying to turn a trussed roof into something else is. Costs are high if done right, on up to the cost of the whole house (and potentially lives) when it collapses if done wrong. Removing the roof and building a second story might well be the least expensive way to get to what you want.
    – Ecnerwal
    Oct 14, 2021 at 0:10
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    To clarify, it is a second story, but as far as the overall term for the type of house it would be called 1 1/2 story, since the second floor is under the roof, not more exterior walls with a roof above. Yes it would take the engineering study to even begin something like this. A truss roof has the roof load spread over the whole wall section with point loads in various places. You would need to go with a "conventional framed roof". It has its load spread over the wall section as well, but the point loads will most likely be in different places, that's where the problem lays.
    – Jack
    Oct 14, 2021 at 1:53
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    To add, the whole roof comes off, as in standing in your first floor and look at the sky. Seriously, what you want to do will be VERY costly. The way you think it could be done seems to make sense, but there is no practical way to add all the needed framing, then remove the framing you don't need.
    – Jack
    Oct 14, 2021 at 1:59
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    Try it this way: You do not have a 1.5 story structure. You have a 1 story structure with something on top of it that is not any kind of story. You have to remove that, and build a second floor. You might choose to put a flat roof on it and have a full two stories, or a sloping roof and get what real-estate agents call "1.5 stories" which is really two stories but one of them is smaller. Either way you need to build for a 2nd level. You don't have one, it doesn't matter how small the floor area is that you plan to build.
    – jay613
    Oct 14, 2021 at 12:28

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