600mm Higher

Got an email from the builders on Friday. Apparently council has come back with the fact that our house will need to be 600mm higher (current level is 300mm below 100 year flood level and you need 300mm extra clearance). There are some possible pros and cons to this although all of them are highly dependent on costs:
Pros

• higher aspect to the house, ie. better street presence.
• possibility of using stumps rather than slab giving me a chance of making a cellar and putting gas ducted heating under the house rather than blowing down from the roof.

Cons

• most likely more expensive, however it may not be once the builder cuts the cost of the fictitious tree.
• delays in building times etc. due to new plans.
• more likely to have creaking floors etc. 

I got a ball park quote of over $15k to go for stumps, however I don't know what previously quoted costs can be deducted if we go for this option.

Supposedly we will get a detailed cost on Monday.