As the need for defence decreased, domestic architecture developed. The transition in Scotland was most pronounced in the reign of James VI. Peels were enlarged into L and E types of building. The castle designed for residence developed, as Drochil; and later the seventeenth-century mansion house, as Traquair and Elibank.

In the Border keep, which had utility stamped upon it, the corbel was designed to bear the parapet; the machiolations to allow guns to be fired from it; the corner turrets to sweep with fire the sides of the building; and the gargoyles to carry off water from the parapets. But as the need for defence disappeared, these useful features of the building were converted to other purposes, or losing their significance, were employed simply as ornament: the turrets became chambers, the corbels were reduced till they became mere chequered bands, as at Drochil, the parapets were absorbed in the walls, and the bartizans disappeared, or became a balcony as at Neidpath. Hence the leading features of seventeenth-century architecture became picturesque turrets cornered out of angles, roofs high pitched with crow-stepped gables, and detail ornamentation with such Norman types as the cable, billet, and dog tooth, as seen at Traquair. The introduction of the Renaissance style was also characterized by a tendency towards uniformity of design, as seen at Fairnilee. Still later, in the eighteenth century, the period began to be marked by the absence of dormer windows, and by the introduction of the unbroken horizontal classic cornice at the eaves, as may be seen at the Whim.

That most interesting mansion, the Glen, was originally a farm-house, to which Playfair, the Edinburgh architect, designed additions. In 1852 Charles, afterwards Sir Charles Tennant, Baronet, of the Glen, purchased the estate and the mansion-house. The house was demolished and the present building, in old Scottish baronial designed by David Bryce, was erected.

The antique aspect of Traquair House or Palace has probably been better preserved than that of any other inhabited house in Scotland. Of Renaissance style and composed of several buildings, it received its present character from John, first Earl of Traquair (1628). The old castle forms the northern portion of the building. The house and offices make three sides of a square, about 100 feet either way, with a beautiful iron railing with stone pillars at intervals and an entrance gateway in the centre. The main building opposite this is four storeys high, with frontage to courtyard and outward or N.E. face, of about 122 feet. The side wings with attics are one storey high. On the N.W. side, which, owing to the fall of the ground has an additional storey, there are the stables and offices, and above, a chapel with sacristy. A high terrace, 17 feet wide, runs along the N.E. side of the building with stairs leading down about eight feet to a lower terrace, at either end of which there is a pavilion with an O. G. roof; a second stair leads down to the banks of the Quair Burn. The building belongs to three periods: first, the old castle on the north; then, the extension (1642) to the S.E., the whole width of the first ; finally, the low wings (1695), the terraces and pavilions and the grand entrance gateway. An avenue leads from the front southwards. It is now overgrown with grass, and has been closed for more than 200 years. The famous gateway which opened on to this avenue with its bears rampant and its fine hammered iron railing with ornament of fleur de lys is regarded as the prototype of the gateway at Tullyveolan in Scott’s Waverley. The interior of the house has been little changed since Stewart days. A room on the second floor of the N.E. part of the house has painted decorations on one of its walls—scenes of Eastern life with floral scrolls, and scriptural quotations in old German lettering.

Other buildings, interesting as they are, can only be mentioned. Darnhall with its fine avenue of limes is of Renaissance type, having the appearance of a French château. In the seventeenth century, next to Traquair, it was the finest mansion house in Peeblesshire. Dawyck, surrounded by its beautiful and historic woods and built by Sir James Naesmyth early in the eighteenth century, was in 1864 replaced by the present mansion house of Scottish baronial design. Opposite to it is Stobo Castle, for long the seat of the Montgomery family. Built in 1805-11 by James A. Elliot and situated on an eminence overlooking the Tweed, it presents a bold and striking effect. Halmyre House, Scottish baronial, near the Dead-burn, was originally a fortalice, part of which is preserved in the lower storey. Lamancha, formerly the Grange, was built by Robert Hamilton in 1663. It was sold to the Dundonald family and its name changed to Lamancha by Alexander Cochrane, son of the eighth Earl of Dundonald, and an Admiral of the Fleet. The Whim, Renaissance, built by Archibald Earl of Islay (1730), is a massive square, three-storey house. Macbie Hill, adjoining Halmyre, was in the sixteenth century a Border keep. At this period it was known as Coitcoit, according to Nennius the place of King Arthur’s seventh battle. The house, whose name was softened to Coldcoat (Coudcoat), was purchased by William Montgomery of Ayrshire and the name changed by him to Macbie Hill, which became the original home of the Montgomeries of Peeblesshire. Spitalhaugh, Scottish baronial, came into the possession of the Fergusson family in 1833, after having passed successively through the hands of the Douglases, the Hays, and the Murrays of Blackbarony.

Returning now to Selkirkshire, we must note Ashiesteel on the south bank of the Tweed, between Walkerburn and Clovenfords. It was originally a peel, and then a "decent farm house." It is now a low straggling whitewashed building, considerably enlarged since Scott occupied it. The older walls are extremely thick. In the grounds is the "Shirra’s seat," where Sir Walter Scott wrote much of Marmion. Fairnilee, dating back to the fifteenth century when it was held by the Douglases and the Kerrs, in 1700 came into the hands of Robert Rutherford, one of whose daughters was the famous Alison. The house is a long parallelogram, with entrance door in centre and turrets at each end, ornamented with dog tooth and other "revived" ornaments. Other mansion houses in the vicinity are the new mansion house of Fairnilee, on the opposite side of the Tweed, and the old Castle of Torwoodlee, the scene of one of the last Border raids in 1568. The Haining, near Selkirk, built like an Italian palazzo, is one of the finest mansion houses, and is surrounded by perhaps the most beautifully designed gardens and policies in the south of Scotland. The grounds are ornamented with statuary by Canova, and the design of house, gardens, terraces, lake, parks and woods combined with picturesque surroundings forms a most harmonious composition. Philiphaugh in 1792 was an old house with columbarium, orchards and planting. The modern mansion, Scottish baronial, is situated at the foot of a beautifully wooded hill. It has fine terraces along its front, whence extensive views may be had of Yarrow and the country beyond. Bowhill, a name dear to every lover of Scott and the residence of the Dukes of Buccleuch, is built in Renaissance style. Previous to 1455 it belonged to the Douglases, and in the eighteenth century it was acquired by the Dukes of Buccleuch. Duke Charles extended the house and gave it its present appearance. Scott with the affection of a retainer has made the setting of Bowhill for ever famous:

"When summer smiled on sweet Bowhill,
And July’s eve, with balmy breath,
Waved the blue-bells on Newark heath;
When throstles sung on Harehead-shaw,
And corn was green on Carterhaugh,
And flourished, broad, Blackandro’s oak,
The aged Harper’s soul awoke."