10m bi-folding or patio door?

teneighty

You need to ask your "architect" how he intends to get that to stand up.


It will require a massive steel frame to support the extension roof, first floor master bedroom and 10m span to the rear sliding folding doors.


Personally, I don't think it is possible without a major re-design.

ey143

I'm not architect but why would it be difficult to get a 11m steel beam to go across the width of the new extension and sit on the inner load baring walls? Getting the beams into the house shouldn't be a problem because it is a straight run to get to the garden via the garage.

Dont be confused, the width of the extension is 14m, so we can use the wall between the utility room and the bifolds to rest a RSJ beam on to it.

Does anyone think by having a pilar wall is a better and much cheaper option? My only concern is losing a clear vista into the garden.

teneighty

I don't want to be the bearer of bad news but you really do need to get it resolved as it does need to be re-designed to avoid costly changes later and wasted time.


A steel beam to span that distance taking the load of the extension roof and point load from beams supporting the first floor master bedroom would be immense.


Looking at the plans and 3D images I can confidently state that they have not been designed by a qualified architect and probably not even a qualified professional architectural designer/technician.


If they have made such a fundamental error to design something that is un-buildable it must call into question their competence.


Sorry, no wish to be harsh, but I think you are heading for problems.

Doozergirl

teneighty wrote: »

You need to ask your "architect" how he intends to get that to stand up.


It will require a massive steel frame to support the extension roof, first floor master bedroom and 10m span to the rear sliding folding doors.


Personally, I don't think it is possible without a major re-design.

I'm with you. I note that there aren't any buttresses marked to hold the massive steel beams in the original house opening. Even small openings need those.

My gut feeling is that it would probably be cheaper to build an even bigger extension and have a bigger house than to engineer the proposed. We have done very similar on a couple of occassions but left the original L-wall in place.

Is he looking after building control and have you suggested a budget for this work?

blackshirtuk

ey143 wrote: »

I'm not architect but why would it be difficult to get a 11m steel beam to go across the width of the new extension and sit on the inner load baring walls? Getting the beams into the house shouldn't be a problem because it is a straight run to get to the garden via the garage.

Dont be confused, the width of the extension is 14m, so we can use the wall between the utility room and the bifolds to rest a RSJ beam on to it.

Does anyone think by having a pilar wall is a better and much cheaper option? My only concern is losing a clear vista into the garden.

I would definitely be having a chat with the architect about the structural calculation and cost of what is being proposed.

The utility wall may well not be strong enough to carry all the weight of the first floor and the roof and the extension roof.

we have a 2m wide walkway at the side of our house but was still advised that the steel would have to craned in due to the weight. Something about the weight and danger to builders, so I would think the idea of taking it through a garage etc would be a non starter!

With the crane and the weight comes expense, seem to remember crane was £2k an hour (and you had pay travelling time) plus the crane people would need you pay for indemnity insurance which they would quote seperately.

Did the architect give you a ballpark figure for the build?

Pockets for sliding door,
if they wouldn't all fit into the utility could you create a wall/pocket at the other end (would reduce opening) to contain half of the doors and then middle opening?

Windows cooling effect,
your build is going to so well insulated that a couple of windows wont hurt. Our extension was the warmest room in the house during the winter. Building control will make sure you have lots of insulation. since we built ours last year regs have changed to add another 50mm to the roof! Wouldn't add value but would add a lot of light at very litlle cost.

Also don't understand why you need 2 planning applications?

ey143

I see the point you are making - it is the area where we remove the load bearing wall supporting the 1st and 2nd floor right, not the patio area which I was looking at?

We haven't got to the stage of preparing technical specifications nor structural engineers, we have only a few weeks ago put in a PD application to the council...so I could be talking out of my back side here, but this is what I have told him, that I want to avoid a column which obstructs the view (having spoken to two builders, they say this part is ok - havent talked about the internal removal of the wall yet).

The architect is RIBA qualified. I work in Risk so have gone to great lengths to check people's credentials before I employ them.

All of the internals are subject to revision when a structural engineer looks at it I suppose, so nothing is final.

The architect has suggested a private building regs company - Butler and Young.

ey143

We're changing the frontal elevation of the house too so will need planning permission once we've built the extension under PD (council does not allow both applications at the same time). See image below and after. The front is very oddly shaped roof line and we want to move the door to the centre of the house (currently at far left) and extend a porch to make it part of a room.

All in all, we're talking over 6 figures, so not a small sum.

choccyface2006

blackshirtuk wrote: »

sorry cant remember the exact quote but seem to remember is over £10k .

If the length is 10m what sort of width are we talking? Ours was 5m

The reason i ask is because at 4.6m (half the length) we were able to use 8 x 2 wooden beams interlocked into the steel in the middle.

Once you get over this span the price of the beams really increases.

I am not normally a fan of modern houses but WOW! I could be quite happy living there!

Sarah

Doozergirl

I thought that I should add something to my earlier post and be positive about it, so I started to draw out the key area points that need supporting, where the possibilty lies to support it all (essentially the utility gap in the windows will take all weight of upstairs along with the kitchen wall of the original house) but then realised that all possible support on the ground floor has gone. The guts and structure have gone. In a big house, the support lies within as well as in the original exterior walls. Not only are some of those exterior lower parts missing, any possible interior walls have gone too.

If this is a million pound build and you intend to essentially erase the original house, why don't you knock it down and start again? It's arguably cheaper before you take into account the fact that you pay zero VAT as oppose to 20%.

About to run out of battery - will edit!

ey143

The idea behind our 8x10m open plan room, was based on a design we saw at another house as part of a house for sale viewing. Granted the guy was a builder but I don't think he would build something similar if he meant spending an absolute fortune.

Looking at the plan again now, I can see and better understand the points you make which never cross my mind before because I though it would be do-able as the architect drew it. Of course his caveat was that it all depended on the structural engineer's recommendation.

I'm not averse to having columns to support an RSJ where the original supporting wall was or even another column somewhere else in the room as long as it doesn't block the patio area.

I'm interested to know what improvements you think I can make to achieve what I want ie thickness of the columns, how many and where to position them.

Thx.