Which way round do you do things for an extension? Has anyone added another floor to their house?

[sorky]

We can't afford to move to a house big enough and do love the house we're in.
Some houses in our close are 2 storey like ours, some are 3 storey. We want to add another floor to our house.

What is the process? Do you find a builder first? Get a surveyor to price the work first? Acquire planning permission first? Or draw up the plans?

Also how much can I expect it to cost (roughly)? Is £100 per sq ft about right?

Can only answer on the cost - £1000-1200 per sq metre, whether that be ground floor/foundations or upper floor/roof.

By three-storey do you mean that you want to do a loft extension or actually build an extra storey and a roof on top of that? If it is the latter, then you will need to speak to your planning dept about the likelihood of planning consent and then get a structural engineer to look at the complexities of building upwards. Some houses, such as Georgian townhouses, lend themselves quite well to a mansard top storey but I can't think of any off-hand that I've seen where people have just built an extra storey.

£100/ft = £1100/m but it is very much a rule of thumb and depends on the region, house age, remedial work etc.

It's hard to explain lala, it's raising the roofline up to the same as a 3 storey house two houses away, so yes it's effectively another floor.

Do you think the costs will be the same as for a 1st floor extension?

For a job this big I'd start with a trip to the planning office at your council to see if there is any chance of getting planning permission. Most councils hold clinics for householders at a fairly nominal charge. Then I would move to architect and maybe (depending on architect) a project manager too.

Architects seem to come in two types - creative ones that are rubbish at the practicalities and practical ones that are a bit boring with their designs. Go and see at least three local architects - your council may be able to give you a list of local architects they have agreements with.

It sounds a really huge job, sorky. I can't quite picture what you are trying to do but, if it is a period house, the foundations could be quite shallow so those might need reinforcing which is expensive in itself before you even start. As I say, the only time that I have seen extra storeys added are of the mansard type on cottages/townhouses that have hidden roofs behind parapets like this dollshouse or developers that have added a "penthouse floor" on top of blocks of flats. If some of the houses on your street were originally three-storey and others are two-storey then I think you may have difficulty persuading the planners to let you go up but, if others have added a floor, it may make it easier for them to give you the nod.

It's a terraced street, built 1980, and is a higgledy mix of two and three storey properties.
Mine is two storey and we want to add another floor so it will be three storey. Essentially it will look exactly the same as the other three storey houses in the close.

I'm thinking maybe 40K, raising the floor level will give us 3/4 extra bedrooms and a bathroom. We envisage the roof will be reused as far as possible.
To move properties will quadruple our mortgage, this is the only option, nightmarish as it does sound.

Thanks for the advice, will contact a builder we know tomorrow and the council for meeting info