Do we need an architect and/or an engineer?

Scallion 'ater

We moved into a new house last year. Its a detached 4 bed timber frame.

We want to extend out the back to create an extended single storey kitchen/living area which will be used as a sun room. The space we have earmarked comprises about 230 sq. feet. It would effectively comprise of three new walls, with a lot of glass in two of them and a couple of velux windows in the roof.

I could draw it out roughly myself and indicate where wiring and plumbing for a radiator should go etc. and then give it to builder to work on. Seems straightforward, although I am a complete novice in this area, but my big concern is that we would intend knocking out part of the back wall, about 4 and a half feet of supporting wall which is situated between a back window and the french doors both of which would be removed to form a total wide opening comprising of about 13 feet. This would be about half of the total existing back wall.

Presumably a steel support in excess of 13 feet would be required but my concern is whether we should have an architect draw up detailed plans or could we just get a builder and work on the basis that he should know what he is doing and won't cause the house to collapse when he goes knocking out virtually half of the back wall?

Maybe we need to get an engineer and if so how and at what stage should I go about looking for one - do we leave it to the builder or get an engineer ourselves to look at it before we ever go near abuilder?

Or, would we be safer getting an architect and let him/her take care and resonsibility for everything. Just seems to me to be a possibly unnecessary substantial expense for what is a very straightforward design.

Any advice would be appreciated, particularly in terms of whether removing such a substantial part of a supporting wall in a timber frame house is a potential problem. Thanks.

galwaytt

Scallion 'ater wrote:

....could we just get a builder ....work on the basis that he should know what he is doing .

Sorry, but that has to be Quote Of The Week !

No, it's not even an architect you need - it's a structural engineer. You'll also need to contact the timber frame manufacturer and get a drawing for the wall, and get their engineer to come up with a drawing for remodelling their panel, otherwise you've invalidated any kind of warranty. Remember, in your TF house, it's the TF that's carring the roof, not the blocks on the outside, so you just can't take the chainsaw to the TF either.

Mmmmmm, interesting project, I grant you......

muffler

As galwaytt said, get yourself a structural engineer