The building had, since the 1920s, been used by the School as an Armoury. A wooden hut had been added on the north side to provide storage space and most of the first floor windows had been blocked. There were already plans to move the Armoury nearer to the main school buildings, but it was some time before this was accomplished and work did not start on the Gothic Temple until 1969.
First to be dealt with was the stonework. The walls themselves were in reasonably good condition and only required repointing, but the parapets and pinnacles needed more attention; several of the stones were broken or damaged by decayed iron ties. The turrets also had to be partly taken down and rebuilt, with some new stone incorporated. This work was carried out with care and skill by Messrs Norman Collison of Bicester, the builders for the Temple's restoration.
The original roof had been replaced earlier this century with one of bitumen, which was beginning to wear out. This was taken off and a new slate roof laid instead, with new lead on the flat areas.
Traces could still be seen of the weather vanes on the tower pinnacles and old photographs showed that these had survived until quite recently. Using these and old prints five replicas were made and fixed in position.
The greatest effect upon the appearance of the building, after the removal of the hut, was achieved by unblocking the upper windows. There were some remains of wooden casements, but these were not original and were badly decayed. Newly-made steel frames were inserted instead, following the profiles of the openings.
The windows in the tower and turrets were blocked with masonry as part of the original design, pierced only with small quatrefoil openings. To make the turret rooms lighter, so they could be used as bedrooms, bathroom and a kitchen, it was necessary to open up the least visible of these. Once again they were fitted with simple metal framed casements. Some coloured glass survived in one bathroom window.
The central glass doors on two sides of the ground floor were another new introduction, again with the aim of making the building lighter and more agreeable inside. Luckily enough lead masks were salvaged, from the outer faces of the two solid doors they replaced, to make up a complete set on the remaining door.
Inside the Gothic Temple, apart from the work required for the conversion of the building such as introducing plumbing and electricity, the main task was the restoration of the painted ceiling under the dome, depicting the arms of Lord Cobham's ancestors. It was in poor condition, the plaster badly cracked and the paint itself decayed and flaking. It was most carefully and skilfully restored by Michael and Benjamin Gibbon in 1970.
The walls of the central rotunda had been painted in the colours of which traces remain, probably by the School. Because there was no trace of plaster on the walls, it was thought that they would not have been painted originally and Nattes's drawing of the interior, which was only discovered later, confirms this. Where the paint went straight onto the bare stone it was cleaned off and only where the surface was plastered was new paint applied. In some places rather messy pointing was revealed on the stonework. Although not original the mortar is quite old, which might indicate that the painting of the interior as a whole happened slightly earlier than was thought - in the late 19th century perhaps. The turret rooms were all completely redecorated.
The stone floors downstairs are mainly original, although some tiles needed replacing. On the gallery the original floor had been replaced with concrete, probably at the same time that bitumen was laid on the roof. In the two bedrooms the floors were raised to bring them nearer the windows.
The gallery balustrade is original, though painted in a new colour. The marks of the rifle name plates and fixings from Armoury days can still be seen on it. All the internal doors, like the glass outside doors, were fitted in 1970. The kitchen fittings were also designed by Mr Creighton, to make best possible use of the very restricted space.
The Gothic Temple is one of the very finest examples of the kind of building which the Landmark Trust was set up to help. It would be inconvenient to live in all the time and would require disfiguring alterations to make it less so (as even recent attempts to improve the heating sadly show). On the other hand it is ideally suited to short term occupation. Under these circumstances all the excitement of its architectural form can be enjoyed, without a lasting prospect of the practical drawbacks.