History of Membury services

The upstairs dining area in the 1970s, with the ramp on the left.

Membury services opened in 1972, designed to slot in between Leigh Delamere to the west and an undetermined site to the east: probably Ashes Copse, possibly Knight's Farm. An alternative site for Membury was considered nearer the Ridgeway, close to J15.
When it opened it was the first service area for 56 miles, filling what had previously been an 82 mile gap between Heston and Leigh Delamere. Leigh Delamere was itself newly opened.
The Membury site was opened to tenders in 1969.
Design
Ross originally wanted it to be a replica of their first site at Leicester Forest East, but they couldn't afford to manage the traffic on the M4 whilst the bridge was being built. Even so, remnants of the idea can still be seen: both sides have a restaurant on a second floor which is accessed from a staircase, with the option of eating outdoors on a terrace. Moving the restaurant upstairs creates a rare bit of space in the rest of the services.
The architect was H. V. Lobb & Partners. The distinctive building design with its high roof and open views was noted upon opening for being very noisy and exposed. The idea was that both sides would have large windows facing south, along customers to appreciate the better views.
Both buildings were shaped like a T, with offices in the long leg and a concourse running along the top. The concourse had doors at each end, and, on the westbound side, toilets at the east end. In the middle was a take-away building and a shop, with more offices at the west end. Stairs and a ramp took people to the large restaurant area upstairs. The west end was designated for lorry drivers, while the north side was where all the kitchens and servery were. The west and east sides were flipped for eastbound traffic.
Inside it was brightly lit, with red/orange colours everywhere and pictures of trees along the walls.
The long downstairs corridor became a magnet for vandalism. An eastbound spiral staircase, provided at the rear of the building for staff use, still exists today but is now surrounded by offices.
The eastbound petrol station has an unusual layout whereby refuelling vehicles face what appears to be the wrong way. The site is 40.75 acres in size.
Changes

In 1977, Ross took the unusual step of adding a garden centre to the westbound services. The Department of Environment approved the idea, but the local authority initially objected. A local garden centre ran the facility, and in exchange they agreed to maintain the grounds of the service area for Ross.
In 1977 Egon Ronay rated the services as "just acceptable". He found it clean and described it as an "architectural masterpiece", and it served "reasonable" convenience-based food.
In around 1978, Ross added new shops to Membury. These took the form of a large, flat building built to the side of refurbished main entrances. The main entrances changed from rounded corridors to a more simple, square style. The old shops became games arcades.
The restaurant appears to have been replaced with a free-flow design named 'The Buttery'.
Welcome Break Era
In 1984 Motoross became Welcome Break. Welcome Break provided separate buildings for their sister company, Happy Eater, to operate in, positioned next to the car park on each side. These included their iconic playgrounds.
They took Ross's idea of extending the westbound dining area and made it larger, with the extension housing new internal and external staircases. Downstairs, the space was used for a larger takeaway restaurant named Burger Break, and a larger games arcade. A strange, tall, curved cover was provided over the main entrance.
Welcome Break became part of the Forte group in 1986. They tried twice to build an eastbound Travelodge, and also provided escalators to the dining area by the eastbound main entrance. This created a new entrance. The game arcade was later moved to the entrance, a second shop was provided next to the existing one, and a customer service desk was provided in the main corridor.
Forte wanted to build a tie rack, dry goods shop and shirt shop. A Halfords was later trialled here, along with a coffee shop.
On the upper level was a coffee shop which offered a blend of waitress and self-service catering. The room had a brown, grey and orange décor with a thick striped carpet, and it used a numbering system to deliver hot food ordered from the counter. Fresh flowers and pictures served as decoration. Next door was a screened-off café.
Burger Break would become Julie's Pantry, while the restaurant would become The Granary. The Happy Eaters became Little Chef.
As a legacy of Ross's ownership, the petrol station was owned and operated by BP, instead of being owned by Forte and leased to Shell, as was standard at most Forte services.
Further Changes

In the following years, significant rearrangements occurred at both buildings.
The fast food units - now Burger King and KFC - were moved upstairs. These were joined by Food Connection, which became Eat In, and has now been broken up into more takeaway brands, turning the upstairs area into a food court. Chopstix Noodle Bar joined them in June 2017.
The old Burger Break became a large Starbucks, with steps down into it revealing that it is part of one of the early extensions. Toilets were moved to the office area at the back, creating more space at the front. Large extensions added new Waitrose shops on each side, with eastbound opening in 2013.
The Little Chefs became Red Hen, and closed shortly after. The westbound side became a training centre while the eastbound side was unchanged and appeared to contain a lot of the original furniture. Since 2012, a Starbucks Drive Thru and Regus Express meeting room have used the buildings. The Regus Express meeting room was later removed in 2020 following the coronavirus lockdown.
On 1 May 2017, Welcome Break took over the petrol stations from BP and changed them to their usual partner, Shell. The refurbishment included the Deli2go offering.