Devolution has been "scattergun" and needs to move towards a "durable lasting settlement", according to First Minister Carwyn Jones.
In a speech in Cardiff on Tuesday he said there should be an end to what he described as 15 years of "ad hoc tinkering with the constitution".
Mr Jones called for a new written UK constitution which favours devolution.
He said that "where it makes sense to take a decision in Wales, it should be taken in Wales".
In the speech, at the Pierhead Building in Cardiff Bay, he also said that devolution should be "less of a process and more of an event" - a twist on the words made famous by former Welsh Secretary Ron Davies, who described devolution as a "process not an event".
The speech came almost a year to the day before people in Scotland will vote in a referendum on whether the country remains part of the UK.
If Scotland rejects independence then Mr Jones hopes that his constitutional vision will help avoid any break up of the UK in the future.
"Over the past 15 years we've seen repeated ad hoc tinkering with the constitution. I want this to stop," Mr Jones said.
"We need now to make devolution less of a process and more of an event.
"Once the Scottish referendum is out of the way, I want to see reforms which complement one another, reforms which viewed together create the coherent constitution which the UK currently lacks."
The first minister reiterated his wish that the UK government fully implements the proposals of a review on more tax and borrowing powers for Wales from the Silk Commission.
"I have made clear consistently my hope that Scots will vote for Scotland to remain within the union," said Mr Jones.
"If we are going to secure Scotland's position in the union, we need to have a credible and lasting commitment to devolution in the UK.
"This has to be a commitment which transcends the varying short-term fortunes of political parties.
"My ability to make that case will depend largely part on the UK government's response to the first Silk Report on devolution of taxation and borrowing powers."
On Monday Deputy Prime Minister Nick Clegg accused his Conservative coalition partners of delaying further devolution in Wales.
Liberal Democrat leader Mr Clegg said if he had been prime minister he would have already agreed to give the Welsh government the power to vary tax rates.