you'd need to prepare plans and have them approved by Building Control (typically at your local council but you can also find private companies)
The usual shortfalls in non-compliant loft conversions are the strength of the floor, the fire precautions, and the insulation.
If you try to sell a house with an unapproved loft conversion, the buyers have to assume it is badly done and reduce the price.
In some cases, if it is work that is very common in your area, you might be able to look up plans for similar work on a similar house, and copy their approach. I've done that, but for work that did not require SE calculations (I was doubtless over-generous in the specs, and I suspect the BCO had seen thousands of applications like mine and nodded them though after I had clarified a few questions).
The council website will have pages explaining how you apply.
If there are dormer windows or changes visible from outside, you may need planning permission as well.
I'm not well up on this. There is a section on this forum though.
https://www.diynot.com/diy/forums/building-regs-planning/
The usual shortfalls in non-compliant loft conversions are the strength of the floor, the fire precautions, and the insulation.
If you try to sell a house with an unapproved loft conversion, the buyers have to assume it is badly done and reduce the price.
In some cases, if it is work that is very common in your area, you might be able to look up plans for similar work on a similar house, and copy their approach. I've done that, but for work that did not require SE calculations (I was doubtless over-generous in the specs, and I suspect the BCO had seen thousands of applications like mine and nodded them though after I had clarified a few questions).
The council website will have pages explaining how you apply.
If there are dormer windows or changes visible from outside, you may need planning permission as well.
I'm not well up on this. There is a section on this forum though.
https://www.diynot.com/diy/forums/building-regs-planning/
