The Brooks chose as their architects the long established firm of Paley and Austin of Lancaster. Paley senior was in partnership with the architect Sharpe in 1845, when the Victorians were fascinated by all things Gothic. Paley continued alone from 1851 to 1868 when he was joined by H. J. Austin, whose fresh approach carried the firm out of the dark, heavy period of Victorian High Gothic and into the lighter, more open style of the turn of the century. This was derived from the mid and late 1400s, when the 'curvilinear' decorated style was changing to the elegant 'perpendicular'. It was the style of the times in which the rich woollen merchants of the West Country and East Anglia built churches in their towns and villages, a point which the Brooks would not overlook; yet there are several touches in St. John's that, in their bold simplicity, can only possibly be very late 19th century.

To present the church in terms of facts and figures is to do it an injustice. Its appeal lies in its setting, its completeness and unity of design; control over all additions has been as a direct result of the influence of the Brooks family.

From the beginning they took a keen interest in every detail, and a memorandum exists in which diamond shaped panes were insisted upon for the transept windows rather than the square ones supplied. After this, it is not surprising to learn that the use of stained glass was utterly banned, a seemingly harsh measure which has in fact saved the integrity of the building.

It follows a traditional plan of a tall nave lined by north and south aisles; transepts and a chancel flanked by side chapels. At one point, a stumpy tower directly over the crossing, carrying a large spire was proposed (a design used by Paley and Austin later at Dolphinholme), but its place over the north transept was set from any early stage. The nave, chancel and transepts are roofed in Westmorland greenslate, a favourite material of the 1890s, and the gable ends are supported by tall, flat-cheeked buttresses, another 'sign of the times'. The outside is of local stone with 'York' stone dressings, this being a description of the type, not the origin, of the material. It is as well to remember that the Brooks were quarry owners.

The tower is 122ft. high, and although designed to look as if it has a belfry, could not carry a full peal due to the nature of the foundations. Its single bell was presented by William Brooks, later second Lord Crawshaw, on the occasion of Queen Victoria's Diamond Jubilee and was first rung in October 1897. Cast by John Taylor and Co. of Loughborough, it was collected from Rawtenstall station and brought by horse drawn cart to Crawshawbooth; weighing 15cwt.