Cost of widening a patio door

rufio89

Can’t get a builder round to quote at the moment and it’s probably a job for next year anyway - but currently we have 1100mm french doors in our dining room and I’m looking to replace them with 2400mm bifold doors.

Ive had a look around so I know the approximate cost of the doors themselves, but could anyone tell me a ballpark cost of what the cost would be to widen the doorway and install? Don’t know about wall types but it’s an Edwardian house and the wall thickness is around 30cm. There’s another storey above this room (and then a large attic).

The room is due to be replastered and flooring redone at some point anyway so not concerned about the ‘tidy up’ costs, just want the door in, looking neat from the outside. 

FreeBear

300mm thick walls suggests that it is structural. You will need the following -

Structural engineer assessment and calculations.

Building control approval.

Structural steel work (RSJ).

A builder that knows what they are doing.

Ball park finger in the air, £2K plus doors... More if you are in or near London.

rufio89

Lovely, thank you! 

longwalks1

As FreeBear said.

We had a single story widened 2 years ago, from 1.2m wide french doors to 2.4m bifolds.  As there was nothing above it apart from a slighty pitched roof, it was an easier job to get done.  A Catnic lintel was fitted and the walls cut to the new width.  This was done in a day, and the bifolds were supplied and fitted by a local fitter the following day.  We are in Herts and paid £500 for the building work  and the aluminium bifold doors were about £1,800 fitted.

TELLIT01

There's a big difference between widening an opening in a single storey building and a 2 storey one.  A catnic lintel will be fine on a single storey as there is comparatively little weight above.  For 2 storey an RSJ will be required so cost will be higher.  How much higher will depend to a degree on how easy/difficult it is to get the RSJ into place.

DOH_a

TELLIT01 said:

A catnic lintel will be fine on a single storey as there is comparatively little weight above.

With the OP talking about replacing smaller French doors with wider bi-fold doors, bi-fold's can be top hung and rely on some kind of fixing plate plate. Catnic lintels (along with other manufacturers) can be supplied with bottom plates but the thing to bear in mind is that bi-fold doors will not operate if they deflect more than 5mm. This deflection can sometimes be caused by under-spec'd lintels and which is why a steel beam with a bottom plate is often the preferred and more feasible approach.