I found a really good Title 24 consultancy:
Their website says TAILORED ENERGY was formed in the late 1980's to calculate reports for Northern Californian drafters, designers and architects. These reports are now known as Title 24 reports and they now offer an online service covering the entire state.
They produce in Title24 energy reports for new residential buildings and additions for which they charge a flat fee of $100 (on buildings of up to 4,000 sq ft). They also write Title 24 reports for multi- family and commercial buildings.