It has been a steep learning curve for Hong Kong architects like Felix Li Kwok-hing, who has spent half his time working on the mainland since Hong Kong qualifications were recognised across the border.
There is little doubt that the industry has benefited from Cepa. About half of the business for local architect firms involves mainland projects, says the city's Institute of Architects.
But it is the diminished role of the architect that they need to adapt to, said Li, one of the 412 Hongkongers who have attained a "class one" registered architect qualification on the mainland under the Closer Economic Partnership Arrangement.
"While architects in Hong Kong take full charge of a project from inception to completion, including the supervisory role, the profession has no such say on the mainland," said Li, co-chairman of the Institute of Architects' board of mainland affairs.
Once the architect hands over the design, the contractor and the supervisor take over and they can make minor alterations to the design and the materials selected, often to save costs and time.
"Very often, you find your streamline design doesn't look as perfect as it can be, because contractors don't take time to work out a way to shape it smoothly. You also find the wood colour you chose is a tone up or down in the finish. The difference is minute but the whole feeling is gone."
Property owners and developers are learning about the problem and have started to invite architects to co-supervise work. For example, Li's firm, TFP Farrells, was brought in to monitor construction of the KK100 Tower in Shenzhen, which it designed, to make sure the curve of the curtain wall was precise.
Architects still want one more thing from Cepa: the right to set up their own practices on the mainland.
Although individual qualifications are recognised, Hong Kong architects have to work with a "local design institute"- a private firm - and let it submit their design to the authorities.
"When we passed the Cepa exam and got our individual qualifications recognised, we thought that was the end," Li said. "But then in 2008, we were told we still had to pass another 'legislation exam' in order to set up our own business - and [could do so] only in Guangdong."
Some 224 architects have taken the additional exam, but not one has yet been approved to start a business.