One of the most unusual and dramatic road side roof structures in the country has been listed this week at Grade II. The canopy was built in the late 1950s by Sam Scorer originally as a roof for a petrol station off the A1 at Markham Moor, Nottinghamshire.

Once dubbed by The Guardian newspaper as “Britain’s only architecturally important Little Chef“, the canopy has housed the well known motorway service station restaurant for the last twenty years.

One of the principal claims to the special interest the canopy  is its technical innovation. The original shell concrete roof was designed as a hyperbolic paraboloid, an anticlastic structure that carries great weight by means of convex and concave forces in its shape. It was a daring roof solution that was being experimented with by a number of architects and engineers all over the world.

The building is an exceptional historical and architectural witness of its time: the former filling station is one of the very few remaining hypars dating from the 1950s in Britain. Its architect Sam Scorer, a well-respected pioneer in concrete engineering, specialised in concave concrete structures. Scorer’s importance is recognised by the listing of two of his other buildings: the church of St. John the Baptist, Lincoln (1962-3, Grade II*), and the showroom for Lincolnshire Motors at Bryford Pool, Lincoln (1958-9, Grade II).

The Twentieth Century Society first put forward the canopy for listing in 2004, prompted by a demolition threat from a new motorway junction scheme. The plans were subsequently re-considered and the structure spared.The listing does not extend to to the restaurant beneath it.

In their reasons for designation, English Heritage include the following:

* Technical innovation: it is a particularly direct example of a hyperbolic paraboloid roof, an unusual and dramatic roof solution which was then being experimented with by a number of architects and engineers all over the world. * Architectural interest: it is a dramatic piece of concrete design which displays the hyperbolic paraboloid form in a daring manner.

* Architectural distinction: during a period when standardisation of petrol stations was introduced as an aid to product recognition, the example at Markham Moor is unique by virtue of its technical innovation and individual design.

* Rarity: it is one of few extant hyperbolic paraboloid shell structures from the 1950s and 1960s.

* Intactness: The canopy and four structural supports remain intact and uncompromised by the inserted building beneath.”