At the technical level Gothic architecture is characterized by the ribbed vault (a vault in which stone ribs carry the vaulted surface), the pointed arch, and the flying buttress (normally a half arch carrying the thrust of a roof or vault across an aisle to an outer pier or buttress). These features were all present in a number of earlier, Romanesque buildings, and one of the major 12th- and early 13th-century achievements was to use this engineering expertise to create major buildings that became, in succession, broader and taller. How their visual appearance changed is easy to see if one compares, for instance, the early 13th-century Reims Cathedral, in France, with the late 11th-century Durham Cathedral, in England. A broad comparison of this sort also brings out the artistic ends to which the new engineering means were applied. Skilled use of the pointed arch and the ribbed vault made it possible to cover far more elaborate and complicated ground plans than hitherto. Skilled use of buttressing, especially of flying buttresses, made it possible both to build taller buildings and to open up the intervening wall spaces to create larger windows. In the 12th century larger windows produced novel lighting effects, not lighter churches. The stained glass of the period was heavily coloured and remained so—for example, at Chartres Cathedral—well into the 13th century.

One of the earliest buildings in which these techniques were introduced in a highly sophisticated architectural plan was the abbey of Saint-Denis, Paris. The east end was rebuilt about 1135–44, and, although the upper parts of the choir and apse were later changed, the ambulatory and chapels belong to this phase. The proportions are not large, but the skill and precision with which the vaulting is managed and the subjective effect of the undulating chain windows around the perimeter have given the abbey its traditional claim to the title “first Gothic building.” The driving figure was Suger, the abbot of Saint-Denis, who wrote two accounts of his abbey that are infused with his personal aesthetic of light as a reflection of the infinite light of God. Something similar to what he intended at Saint-Denis was attempted soon after at Notre-Dame, Paris, begun in 1163 (the east end was subsequently altered), and Laon Cathedral, begun about 1165 (the east end was rebuilt in the early 13th century). Perhaps because of liturgical inconvenience, it later became more common to keep firm the architectural divisions between the peripheral eastern chapels, as at Reims (rebuilt after a fire destroyed the original cathedral in 1210) and Amiens (begun 1220) cathedrals, for example. This particular feature of Saint-Denis did not, therefore, have a very long subsequent history.

It is not known what the original 12th-century interior elevation of Saint-Denis was like. Elsewhere, though, the problems that followed in the wake of the increasing ability to build gigantic buildings are easily seen. Possibly the most important one concerns the disposition of the main interior elevation. The chief elements are the arcade, the tribune (upper gallery set over the aisle and normally opening into the church) or triforium galleries (arcaded wall passages set above the main arcade) or both, and the clerestory. These may be given equivalent treatment, or one may be stressed at the expense of the others. Precedents for almost every conceivable combination existed in Romanesque architecture. In a building such as Sens Cathedral (begun c. 1140), the arcade is given prominence, but in Noyon (begun c. 1150) and Laon cathedrals the four elements mentioned above are all used, with the result that the arcade is comparatively small. Subsequently, the arcade came back into prominence with Bourges Cathedral (begun c. 1195). But one of the most influential buildings was Chartres Cathedral (present church mainly built after 1194). There, the architect abandoned entirely the use of the tribune gallery, but, instead of increasing the size of the arcade, he managed, by a highly individual type of flying buttress, to increase the size of the clerestory. This idea was followed in a number of important buildings, such as the 13th-century Reims and Amiens cathedrals. The conception that the content of a great church should be dominated by large areas of glazing set in the upper parts was influential in the 13th century.

The decorative features of these great churches were, on the whole, simple. In the second half of the 12th century it became fashionable, as at Laon Cathedral, to “bind” the interior elevation together by series of colonettes, or small columns, set vertically in clusters. Again, as at Laon, much of the elaborate figured carving of Romanesque buildings was abandoned in favour of a highly simplified version of the Classical Corinthian capital—usually called a “crocket” capital. Under the influence of Chartres Cathedral, window tracery (decorative ribwork subdividing the window opening) gradually evolved.

There is one group of churches, built for houses of the Cistercian order, that requires separate consideration. They tend to be similar, but it is often a similarity of general simplicity as much as of architectural detail. The Cistercian order was bound to the ideas of austerity as exemplified by St. Bernard of Clairvaux. During his lifetime these ideals were maintained largely through the degree of centralized control exercised from the head house at Cîteaux (Burgundy). Thus, many of the Cistercian churches built in England, Italy, or Germany seem to have had characteristics in common with French Cistercian churches. A good French example survives at Fontenay (begun 1139). These buildings probably encouraged the early dissemination of the pointed arch. That they did much more than this is doubtful.

If one examines the architecture outside northern and northeastern France, one finds, first, that buildings in what might be called a Romanesque style continued up to the end of the 12th and into the 13th century and, second, that the appreciation of the developments in France was often partial and haphazard. In England the most influential building in the new fashion was the choir of Canterbury Cathedral (1175–84), which has many of the features of Laon Cathedral. It is the decorative effects of Laon that are used rather than its overall architectural plan, however. There is only a rather depressed tribune gallery, and the building retains a passage at clerestory level—an Anglo-Norman feature that remained standard in English architecture well into the 13th century. Both in the shape of the piers and in the multiplicity of attached colonettes, Canterbury resembles Laon. Colonettes became extremely popular with English architects, particularly because of the large supplies of purbeck marble, which gave any elevation a special coloristic character. This is obvious at Salisbury Cathedral (begun 1220), but one of the richest examples of the effect is in the nave of Lincoln Cathedral (begun c. 1225).

The early stages of architectural development in the Gothic period are untidy and have a strong regional flavour. During this period in Germany, large buildings showing northern French characteristics are few. The church of Our Lady at Trier (begun c. 1235) and the church of St. Elizabeth at Marburg (begun 1235) both have features, such as window tracery, dependent on northern French example; but the church at Trier is highly unusual in its centralized plan, and St. Elizabeth is a “hall church” (that is, the nave is virtually the same height as the aisles), which places it outside the canon of contemporary French building.

In Spain the two most important early Gothic buildings were Burgos (begun 1222) and Toledo (begun 1221) cathedrals. Their architects probably knew Reims and Amiens; but their models were undoubtedly Bourges and Le Mans (begun 1217), since the main internal architectural feature is a giant arcade rather than an extended clerestory. By contrast, Scandinavian architects seem to have been influenced, to begin with, by English buildings. Certainly there is a strong English flavour in the 13th-century Trondheim Cathedral (Norway).