Extension Possibilities Removing Walls ??

Hi, I’m a new member & in the process of buying a BISF property in Epping Essex.

I have 2 questions though both related.

The 1st is has anyone ever replaced any of the walls with standard brick & block cavity?

My initial proposal would be to submit a planning application to build a 2 storey extension to the side where the current garage is by using 3 major exterior walls with supporting steels to carry the 1st floor & loft joists/roof, & then tie in the existing floor/loft so to remove the adjoining wall.

On the basis that’s clearly doable, the theory would be to on a 2nd phase re support the roof & remove the 1st floor completely, then carry the front facing upper 1st F wall whilst replacing the lower section with brick/block cavity and then repeat to the upper floor to carry existing front of the roof. Then repeat process to rear wall leaving only the party wall in place of which a double skin internal wall would be built tied into the new front & rear brick walls. Then fit the 1st floor and loft floor to ultimately have a full 4/5 bed brick built property.

I know it may come across as ambitious though construction is my game and seeking to put value on to what is an outstanding plot.

The 2nd question is that if planning didn’t go ahead has anyone had experience of putting a full width extension to the rear using steel to open up the kitchen / rear dining?

If so are the existing steels ok to support by welding a new steel in/box frame or has piers been a requirement. I’m just not sure what loads these constructions can take.

Cheers for anyones thoughts or input



  1. It’s certainly possible to build a double-storey extension at the side as there are one or two around here. I would imagine that it is commoner (as it is easier) to leave the steel frame in the old external wall in place rather than replacing it with masonry.

    As to the other question, it may be possible, but the obvious question is why? It would be a massive job to replace walls that don’t have anything wrong with them in the first place. There’s nothing structurally unsound about the steel framed walls of a BISF house. If for some reason you would much rather have brick walls, wouldn’t it be much cheaper and more convenient to buy a brick-built house instead?

    Personally, I think I’d find a traditionally-built house very boring after this BISF house!

  2. Hello Jeff & Warm Welcomes :0)
    Gosh, your project does sound ambitious a thrilling at the same time. I hope you manage to get it completed and share the stages with us.
    Anyhooo back to your question. I do know one person who lives near to me who has completed a full side extension to his property. It has made the house much larger but I am not sure how he tied the extension in, if that’s the right phrase.
    I willtry to pop and see him for you in the next day or so as he might be able to give me some information that may help you. I don’t know the owner and he might tell me to get lost haha but I will at leat try as it’s all about sharing the knowledge here. I just hope he doesn’t think I’m a planning inspector lol.

    Sorry I can’t help with the rest as that’s way beyond my knowledge but I will keep you informed, fingers crossed, hey ho and all that.