Extension advice

Barwickpaul

Because I dont believe it isnt possible for someone with some knowledge to give a ballpark with info given and making some assumptions.

Your response seems to be not possible to give any ballpark figure in any circumstances on any building job which I dont accept. I’ve been wrong before though!

naf123

To make it easier to explain,

OP - looking at the picture below, assuming your roof line is in black line do you want the new roof (red line) to be like the left or the right?



https://imgur.com/81RUuCa

Barwickpaul

Cant see a picture on the post or the link?

Barwickpaul

Just a black picture for me. The current roof has pitches on all four sides so no gable ends. Pitch is pretty gentle and theres a ridge in middle running along width of original house. Flat side extension roof to one side

In ideal world i would like the new roof to be v similar design but covering the entire house new back extension and existing side extension. The roof would need a slight overhang of the rafters on the front of side extension because of the 30cm set back. Eventually I may put some external insulation on the front of side extension to hide the set back.

naf123

Barwickpaul wrote: »

Just a black picture for me. The current roof has pitches on all four sides so no gable ends. Pitch is pretty gentle and theres a ridge in middle running along width of original house. Flat side extension roof to one side

In ideal world i would like the new roof to be v similar design but covering the entire house new back extension and existing side extension. The roof would need a slight overhang of the rafters on the front of side extension because of the 30cm set back. Eventually I may put some external insulation on the front of side extension to hide the set back.

Try this

https://imgur.com/81RUuCa

Barwickpaul

The one on the left should still give a ridge line lower than neighbours

Doozergirl

Not bothered about planning rules - required set backs and extensions being subordinate to the house.

Not bothered about the rules of geometry

Not bothered about about how said geometry will make house look like a wizard's hat

Mentions after 20 odd posts that the entire roof is hipped, which means it has to be supported so the ridge line can't move back and remain hipped unless you support it with steels.

Please get someone to design it first.

You can believe waht you like but no one with any idea of what it takes to design and build a roof is going to give a layperson a ballpark figure to build a roof that defies logic. Sorry. I'm trying to help but it's quite simply obvious when on paper.

The only picture we've even seen came from someone else.

Barwickpaul

I am concerned about planning and this discussion has increased my concern that planners could stop me from doing what I want. Hopefully there are ways round though as I do see some examples of the sort of extensions I like with no ugly set backs and original melding into the extension.

Ive said a few times I understand that what I want (which weve established I dont have budget for anyway) will increase the ridge height. This wont leave it looking like a wizards hat even a proportionat 2/3rds inc in ridge height will look fine as current roof is very shallow slope.

If anyone had asked im more than happy to give more info about the house. If steels are needed then ok.

I certainly cant design a roof or a house but Do want to be able to tell architect/ technician exactly what I want them to draw up.

No idea how to post pics and no one has asked for one!

Doozergirl

The ridge beam (steel) need something to sit on. With a hipped roof, there is no structural wall for them to sit on at the sides and so the support needs to come up in the form of a structural wall through the centre of the house. The house is designed around those limitations.

If you change where the centre of your house is, there is nothing to hold the steel for a hipped roof at all. You'd need upright steels through the middle of the house, which involves digging out footings for in the middle of your house for the steels to rise up, which would almost certainly be in an awkward position and damage every room in your house and need a crane to get them in. That's without considering lateral forces on the roof/house which probably require even more steel support.

My point is that, in this case, you can't tell someone who to draw because they have to design it to stand up. And you're not taking any of it into account. That's okay, because you can't be expected to know, but a sensible conversation with an architect will give you proper advice on the rules of planning and physics.

You're jumping the gun so much. I know you think you're making things simple, but renovation doesn't work like a new build where you design what you want. Renovation is about designing within some quite tight restraints.

Barwickpaul

Thats really useful info thankyou. The house does have solid internal walls but funny When I go into the loft which is mostly boarded out theres no internal wall in it providing support to the ridge.

Is converting walls to structural gable end economically feasible to support a roof? If a no go can avoid bringing up possibility with architect when we do get to that stage.