Box Frame, Is this really the case?

[Krishane]

Hi All

I am having a single storey extension done in my mid terrace house under permitted rules. So 3 metres out and up to 4m high. My architect has said I need a box frame put in as the back wall of the house will be knocked through so it needs the weight supported.

I have showed the plans to two different builders and they have said this frame is not needed as its over cautious and single beam above with columns on either side of the side walls would provide enough support which would reduce my costs considerably.

Will the single beam be ok?

Any helpful advice is needed.
Thanks in advance.

Kris

 

[freddiemercurystwin]

a box frame put in as the back wall of the house will be knocked through so it needs the weight supported.

Eh, can you elaborate a bit more please?

 

[freddiemercurystwin]

Damn double posts!

 

[Krishane]

The back wall will be knocked down so extension can be built to have open plan kitchen.

The wall that has to come down is the back wall of the building which holds the weight of the whole back wall of the house. This is what the architect has said therefore he said you I need a box frame.

 

[Deluks]

Either or. What the engi has suggested is in his opinion the best solution, it will certainly take up less space than big bulky pillars.

*edit* oh, an architect. Same answer but might want to suggest the alternative and see what he says.

 

[Krishane]

The architect said he does not recommend changing the plans which do not include the box frame. He said he would not feel comfortable in doing this and also said he would only change it if a full plans application is made as he seems to think it won't be suitable any other way. This adds on 8 weeks to the time line which I can't do.

The builders are saying there is no problem with using a beam and that there will be bo problem with building regs. They have said that the architect has been 10 times over cautious with a box frame. Saying that you could hold a train up with the frame!!!!

 

[freddiemercurystwin]

Deluks you seem to know what the OP is going on about, I must be being thick, WTF is a box frame?

To the OP what is the width of the new opening?

Architects are not qualified or insured to be sizing steels, why hasn't a structural engineer been employed to size the steels up.

You're doing this on a Notice presumably? I don't get what you're saying about it'll take 8 weeks etc?

 

[Krishane]

Ok...

The width is 4.6 metres.

The architect is a structural engineer as well.

A box frame is where you have the top steel beam going across and two steels along both side walls. Then there is a steel that is set in the floor laid in concrete which needs to be dug down a round a metre deep. They are all linked together creating a box/square shape.

Hope that helps.

 

[Deluks]

Well it's gotta be steel goalpost or an actual box on the back of the house if the extension contains lots of glazing, or the extension walls/roof cannot support themselves.
The architect must be using an engineer (acting as the go between between client and engi and charging a fee accordingly)
But if you can do it one way you can do it the other, I also don't understand this 8 week bllx, unless the architect doesn't want to go back to the engineer for alternative calcs as the extra cost may 'eat' into his go-between fee
Cynical? Moi?

*edit* Shoulda typed faster. Well now we know.
If you don't like his advice get a second opinion. There's always more than one way to do things.

 

[freddiemercurystwin]

Architect and engineer, thats a new one!

Anyway that's kinda what I imagined but was struggling with the concept. It seems an odd way of doing it, sounds excessive to me, I would go with your builders, a column on a pad foundation at each end and a beam or two thinner ones spanning the opening. Can't say as I've ever come across a 'box frame' as a solution for this before hence my confusion!

Sounds like he's drawn this up without thinking, hence giving you some bullsh*t reason as to why he won't change it!

 

[Krishane]

8 weeks - Is the response time from the council to ok the changes made as he will only want to go ahead with the plans if they are accepted.
Otherwise he is happy for the builders to start the work with box frame as he is happy with this. He said he is worried about his liability.


It seems like I will pay him for the plans and end it with this architect since he wont move forward without this box frame. I may have to pay another architect to change the plans accordingly (goal posts)but in the long run I will save a lot on contruction costs. Builder was saying that box frame work is approx £3000. So I will save that.

He is quoting me around 22k for extension.

 

[Deluks]

Planning changes may take weeks, I can't see technical details on the construction holding things up. Not a listed building or conservation area is it?

 

[Krishane]

No it is not listed or in a conservation area.

I need to get work started soon as and don't want to wait for 8 weeks to get the ok.

When I can start now under permitted rules with another architect who will be on board as the present architect is not.(well...only with this box frame!!ahhhh)

 

[freddiemercurystwin]

For a standard extension finished to a high standard you should be looking at max £1000 per m2 + a bit extra for the big opening!

I can see why he wants his design approved before construction begins but generally Building Control are a lot quicker than 8 weeks. So have the plans already been approved with the box frame design then?

And is your builder booked to start now presumably and you don't want to miss the time slot?

I'd be double checking whether he's doing it or subbing it to an engineer tbh, sounds a bit nervous to me!

Ultimately your architect has a responsibility to provide a practical and cost effective solution if you're not happy you need to discuss it with him before you go paying someone else.

Dare I ask what you've paid this clown?

Edit: price

 

[Krishane]

Its 13.8 metres squared. So accordingly to what you are saying I will be paying too much? I thought 22k was a good price. Oh well.



Builder is not booked. But I need to confrim him this week otherwise will miss time slot.

Architect cost me £800. Used him as he was the cheapest in my area. Took 4 quotes. one was 2k!

He has been good I have to give him fair do's the only thing is the issue of the box frame. At the end of the day it appears this is a big cost so if I can save thousands by not doing it then obvioulsy I will do so.