Universal plan expansion two story from 20x30 to 30x50

[sunovertone]

Hi, I am new to this forum. I am considering purchasing the 20x30 2 story universal cottage plans. I am considering expanding it to something like 32x48. I plan on using engineered trusses and joists. I was just wondering if this was possible? Or still considered structurally sound. I am new to building. My husband has built houses on a few jobs sites,so he has some skills. It will just be the two of us for the most part. But we can get a crane to deliver to the roof, so after it is all framed They will be put right on the roof. Hopefully we will also be putting in a partial walk out basement, with the other half of the house being on a perimeter foundation. Any advice would be great! I would like to consider befor we buy the plans, or maybe look for other plans. But I really like the simplicity of these plans.

[Don_P]

I doubt there would be much useful left, structurally all member sizes would change and dimensions certainly aren't going to work.
What do you need out of the plans, is this for a building dept or is it just working drawings?

[sunovertone]

I will need them for my building department. I realize I would have to take them to a engineer or architect for final approval, however I would like to give them a base. I really like the simplicity of the plans. I wouldn't mind making the plans more like 24x48 or 24x44.  Most of the other plans I am finding on the internet have more complex roofs and dormers and such. I really like this plan because of the simplicity.

[Don_P]

Can you make a rough dimensioned sketch?

[John Raabe]

The Universal Cottage plan has the 20' span (width limit) in order to keep the full width structural spans on the floor joists to easily available engineered joists. With the wider width you are proposing you will need to have a center line beam with support posts running the length of the building to pick up the loads from the floor joists and perhaps the roof trusses. These will now span 1/2 the building width and can likely be downsized. This is very common engineering and your engineer or architect can help design the new wider floor plan and this structural change. I would use the Countryplans Universal plan to help work up your layout ideas and redo the foundation walls and post piers for the new load diagram. You can have exposed wood beams and 6x6 exposed posts stacked to take solid bearing to the concrete support pad in the basement and/or crawlspace.

I named this plan the Universal because it can be expanded in this way. You will have to have the plans redrawn for the larger footprint with beams and posts at the center, but the design itself retains the simplicity of the original.

[sunovertone]

Ooh. I am trying to avoid center load bearing beams and walls. Would I still need them with 24' width span with full span engineered trusses? Or just for 30'?  But what about modifying the length? That should be simple enough correct?

[John Raabe]

Call up your lumber yard and see what they can supply for a 24' or 30' engineered floor joist. Watch the deflection. Building length is adjustable (more of the same).