Warden Leopold Finch was succeeded by Bernard Gardiner, who, for a quarter of a century, fought an ultimately unsuccessful campaign to enforce the statutes relating to residence and the taking of holy orders. His failure in the former respect was to have regrettable consequences for the College's future. In another area, however, he presided over a brilliant success – the replanning of the College buildings. The initiative came from Dr George Clarke, politician, lawyer, virtuoso, and capable amateur architect. In 1703 he offered to build a house on College land which on his death would become College property. The offer was accepted and the cloister to the north of the chapel (apart from its Catte Street wall) was demolished to provide a site for the house. Then came a change of mind and the present lodgings were built in 1704 on a site in the High Street immediately to the east of the 1550 range. Now that the cloister area was available for development, Dr Clarke was able to entertain large designs for the aggiornamento of the college. In about 1705 he planned a double-quadrangle College with a chapel and hall as a continuous east-west range dividing a southern quadrangle, with a central north-south library over a colonnade, from a northern quadrangle with a 'grand dormitory' as its northern range. Variations on this theme were offered by half-a-dozen hopefuls, but all changed when the College received news in 1710 that Christopher Codrington had died in Barbados, leaving £10,000 to the College to build and endow a library – together with his own collection of some 12,000 volumes. By 1715 Hawksmoor had submitted a design which, not surprisingly, substituted a 'grand library' for the 'grand dormitory' and removed the Fellows' lavish accommodation from the north to the east range of the north quadrangle and also to the east range of a new south quadrangle. A loggia was retained as the western range of the northern quadrangle, while a north-south colonnade, shorn of its library over, remained (on paper) the central feature of the southern quadrangle.

Clarke and Nathaniel Lloyd (Fellow, 1689-1723) were among a number of generous benefactors who helped to finance the building campaign. They were appointed to oversee Hawksmoor's plans. A start was made with the chapel, where between 1713 and 1716 Sir James Thornhill rebuilt the Wren screen, painted the chancel walls with huge trompe-l'oeil vases and figures of saints and Lancastrian nobles, inserted painted coffered canvas panels in the roof, and covered Fuller's Last Judgement with an Apotheosis of Chichele, which crowned a marble reredos and wooden panelling given by Clarke to classicize the east end of the chapel. This work was done by 1716, and in that year construction began of what was (until 2020) to be known as the Codrington Library and of the east range of the new Great Quadrangle. This range consisted of a common room flanked by twin towers and link-blocks to the north and south. The north tower was the gift of General William Steuart, and the College owed the two link-blocks to the Duke of Wharton (Edward Young, Fellow 1708, had been his secretary) and to Nathaniel Lloyd. The range was built by 1724 and the hall (1730) and the loggia (1728-34) completed Hawksmoor's remarkable northern quadrangle, in which all the buildings combined 'Gothic' exteriors (matching the chapel) with classical interiors. But by the time of Nathaniel Lloyd's and Clarke's death in 1746 the College had tired of 'Hawksmooring' and the ambitious plans for the new south quadrangle were not continued.

In other respects, too, eighteenth century All Souls lacked ambition. Non-residence became commonplace (and remained so for two centuries), and now that the fellowships were financially more attractive, during the second half of the century graduates claiming kinship with the founder (and often with little else to recommend them) began to swamp the College. There were exceptions to the low intellectual standards, however: eighteenth-century All Souls College can claim the poet Edward Young (Fellow, 1708), a couple of Lord Chancellors, nine bishops and, above all, William Blackstone (Fellow from 1743 to 1762), the first man to lecture on the Common Law at Oxford (in 1753) and the author of the Essays on Collateral Consanguinity (1750), in which he vainly attempted to stem by argument the tide of founder's kin. But the flood continued: between 1750 and 1857 more than half of those elected to fellowships were of the kin of the founder, and almost as many came to the College from aristocratic Christ Church College. A mere twelve per cent of those elected between 1802 and 1857 had been awarded first classes in the Schools; more than half of them were destined for the Church. The tone of the College was unambiguous.