Single Rear extension & dormer extension

You can't guess at steel beam size, it needs to be specified by a structural engineer along with other structural members. Joist sizes depend on span and spacing.
Sponsored Links
does a steel beam go under front and rear dormer from gable wall to party wall? Some dormers i have seen without them.

Also once plan submitted and PW notice served can i start building work (giving building notice) on gable end and rear dormer until planning approved (can take up to 8 weeks) for front dormer?

Need to get a move on before winter arrives. It will be done to building regs. Will have plans done for that too in a couple of weeks.

Last edited:
Normally, beams in that place are to support the floor not the dormer.
Sponsored Links
any steel beams need to be calculated by a structural engineer working in conjunction with whoever is producing the architectural building regulations drawings .

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local