His abbacy was predominantly occupied with recommencing the building works at Vale Royal—which had been in abeyance for a decade—and the assertion of his abbey's rights over a satellite church in Llanbadarn Fawr, Ceredigion, which was also claimed by the Abbot of Gloucester.
[12] The destruction was comprehensive, ranging "from the wall at the west end to the bell-tower before the gates of the choir," whilst the timber scaffolding collapsed "'like trees uprooted by the wind.
"[13] Repairs slowly took place over the next thirteen years, and it was undoubtedly Abbot Thomas who was responsible for the "unique chevet of seven radiating chapels" that were installed, although the overall stature of the remodelled church was smaller than before.
[14] Abbot Thomas had personally contracted with the Master Masons completing the work: they would build the church while he would organise the construction of twelve chapels—and pay for them.
[11] "Emboldened by the revival of royal munificence the abbot and convent embellished their incomplete church with a chevet of thirteen chapels, alternately polygonal and four-sided, at the east end; unique in England, it is thought to derive from Toledo cathedral.
"[11] Thomas performed royal service when required (for example, in 1364 he took the fealty of John de la Pole)[15] and also held a number of offices outside his abbacy.
[23] Even though Vale Royal had received permission from the Bishop, the King and the Pope, Gloucester Abbey still objected, and the case was to drag on many years after Thomas' death 9not being resolved until 1399).