The will to undertake church construction or enhancement is easily accounted for by the desire of local elites (whether rich aristocrats, prosperous merchants or a coalition of the local well-to-do) to demonstrate their wealth and prestige, and by genuine religious belief. The rich and the prosperous were eager to show their status while alive - and to alleviate the suffering of their souls after death - by spending on the reconstruction or adornment of their churches, the church being a focal point of the community. This was not peculiar to East Anglia.
It is well-documented that by the 1400s, the prime era of angel roof building in English churches, East Anglia was rich compared to most of the rest of Britain (see, for example, Mark Bailey's Medieval Suffolk, An Economic and Social History, 1200-1500).
Herring fishing out of Yarmouth and other East Coast ports, leather making, the manufacture and trade of cloth with Northern Europe, dairy farming, dealings in fish and timber with Scandinavia, King's Lynn's position as a Hanseatic port (the Hanse being a sort of medieval Common Market), and Blakeney's rare right to trade with the continent in precious metals and horses all show that the Eastern Counties were highly prosperous and had a wealthy merchant class, alongside the local aristocracy. Both groups were able and eager (for the reasons outlined earlier) to spend on the adornment of their local church.
However, other parts of England were also rich in the 1400s, the wool and cloth producing Cotswolds being a prime example. The Cotswolds too had wealthy aristocrats and parvenu merchants.
Elaborate and expensive churches were built there, as in East Anglia, but angel roofs were not a common feature of the region.
The sophistication of East Anglian expertise in carpentry and wood carving during the C15th-16th has been noted by several writers.
At the level of small scale carving, Arthur Gardner in his book Minor English Wood Sculpture, notes that finely carved church bench ends are found in large numbers only in East Anglia and the West country.
East Anglia also excelled in large scale medieval carpentry and wood carving. This is clearly demonstrated by the distribution throughout England of single and double hammerbeam roofs - arguably the most complex and audacious form of medieval timber roof.
Using Michael Good’s A Compendium of Pevsner’s Buildings of England on CD-ROM, Birkin Haward found that of 188 surviving single hammerbeam roofs in England, 65% (124) are in East Anglia (defined here as Norfolk, Suffolk, Essex and Cambridgeshire). Suffolk has 55 and Norfolk 51, giving these two counties alone 56% of the national total. For double hammerbeam roofs, the pattern is even more extreme. All of the 32 surviving double hammerbeam roofs in England are in East Anglia (21 in Suffolk, four in Norfolk, four in Essex and three in Cambridgeshire).
Hammerbeam roofs provide multiple surfaces for figurative carving, and many of East Anglia’s hammerbeam roofs are also angel roofs.