The Restoration of Bletchley Park 

Bletchley Park

“The work here at Bletchley was no optional extra; no engaging very British sideshow; it was utterly fundamental to the survival of Britain and to the triumph of the West and I’m not actually sure that I can think of very many places where I could say something as unequivocal as that. This is sacred ground. If this isn't worth preserving, what is?”
Professor Richard Holmes, Military Historian. 2009 


“…I walked despondently out of a Council meeting, where… it had been decided that Bletchley Park should be demolished to make way for houses, a petrol station and a small supermarket…

We asked BT, who owned the Park, if we could hold a “farewell reunion” …for the wartime codebreaking staff to say “Thank you” for their magnificent achievements. ...we invited reporters ... to hear at first hand and then broadcast to the nation this almost unbelievable story. It worked! From then on it was simply uphill all the way.

I now often just stand and look, sometimes in disbelief, at the old, sad wartime huts gleaming in their coats of fresh paint, the grounds being restored to their wartime layout; Block B standing high and proud; groups of visitors and schoolchildren listening intently to guides telling the BP story; and everywhere; staff and volunteers hurrying about their business, and I think to myself,

                                 ” Wescombe, we actually made it”.”

Peter Wescombe, volunteer and founding member of the Bletchley Park Trust


In 2014  the Bletchley Park Trust completed the long awaited £8-million Heritage Lottery Funded (HLF) first-phase restoration programme.  

This exciting and innovative project has seen the transformation of the formerly derelict Codebreaking buildings: Block C into a vibrant visitor centre with new introductory exhibition, and the iconic but once derelict Codebreaking Huts 3 and 6 into exhibition spaces that allow visitors to experience how it was to work at Bletchley Park during World War 2.

Areas of landscape have been returned to their wartime character with car parks removed and 'lost' codebreaking Huts discovered. An external soundscape provides visitors the opportunity to overhear period ambient noises and further allows the visitor to be drawn back into the 1940s.

The buildings are designated as part of the Collection with the significance of artefacts and every effort was made to retain as much original fabric as possible. Where replacement was required new material was sourced that was an exact match as shown through the rare wartime photographs of Block C, or was a wartime contemporary from another source.

Alongside the HLF project the Bletchley Park Trust has also restored other iconic buildings: Hut 11 is now a sensory exhibition that allows visitors to explore what it was like for WRNS (Wrens) to work on the Bombe machines, and work on Huts 1 & 11A continues.


Block C, 2012, prior to removal of post war internal walls and restoration. View from spur 7 through to spur 9
Block C, 2012. Spur 8 ceiling
Block C, 2013, during restoration. The post war internal walls have been removed and the original granolithic floor has been revealed
Original Crittall windows awaiting restoration
Original cast iron column radiators awaiting restoration 
Original 1942 First Aid Post discovered after the removal of post war walls. The damage was caused when the later internal walls were added. This has now been fully restored to original condition
Paint analysis of Block C RSJ (rolled steel Joist) beams

“Although the decoration of the buildings at Bletchley was undertaken within 'living memory' it is surprising how information becomes confused over time. Most of our ideas of how buildings were decorated at this period come from post war magazines and media, some of which was in black and white. Our recollection and perception therefore does not always reflect the reality of how things appeared.”

Neilian (Ian) C. Crick-Smith PACR NCCR Principal Conservator Researcher & CoFounder

Wartime acoustic ceiling tiles prior to remedial conservation
Original acoustic ceiling tiles after remedial conservation

Block C housed a number of codebreaking sections that used machinery that was noisy. Acoustic ceiling tiles were used to help reduce the noise from escaping and disturbing those working in other sections in Block C and the surrounding buildings.

Approximately 5,500 original tiles were salvaged and these have been conserved and then repositioned within Block C within the exhibition areas in spurs 4, 6, 7 and 9.

Around 8,000 new tiles were sourced for the remaining areas within Block C and these are a perfect match for the original wartime tiles.


As the wartime buildings are designated as part of the Collection, they have been treated as artefacts in their own right. 

The look and feel of the Bletchley Park introductory exhibition responds to the look and feel of the building in the 1940s. 

Displays are placed where there were once desks, each focusing on a particular aspect or process and using a combination of graphics, object display and multimedia to convey the story. 

Furniture is based on that seen in the photographs of the Block taken at the end of the war.

Block C, 1945. Freeborne Punch Room and Verifier Bay
Visitors watching part of the introductory exhibition film that is projected directly onto the restored wartime fabric of Block C
Block C, 1945.  Hollerith Files in the Freebornery


Hut 3, 2013. Restoration in progress

“If work to restore [the Huts] had begun just one year later, they could have been lost to the nation altogether.” 

Rob Davies, Site Manager Fairhurst Ward Abbotts (FWA)

Hut 3 during restoration showing the double-pitched roof on the south end. 

The  surviving blast walls have been removed in order to underpin correctly and rebuild.

Hut 3, 2013. Roof repairs
Wartime repairs to the roof of Hut 3. Carpenter Bob Watson is pictured
'Time capsule' discovered inside a Hut 11a door

“The paint analysis was able to identify exactly how certain areas of the Huts were painted originally, what treatments were specific to each area and how some differed. 

This is significant as it enables us to understand how the buildings were used; the paint colours, types and finishes that were applied. These of course have a direct effect on how the interiors feel and passing on that 'feeling' to the modern visitor is a vital and integral element of truly experiencing this site.”

Neilian (Ian) C. Crick-Smith PACR NCCR Principal Conservator Researcher & CoFounder

Hut 3 exterior paint analysis cross section

“Had the work not been done before the wind storms in January [2014], the Huts would probably have been reduced to piles of rubble....we were amazed that the Huts were still standing. In some places they seemed to be levitating because all the sole plates had rotted away. Considering the heavy rain and high winds we have had, I would have thought, after that, they would probably have fallen down.”

Rob Davies, Site Manager Fairhurst Ward Abbotts (FWA)

Construction of temporary scaffolding roof, 2013.  Huts 3 (left) and 6 (right). (Hut 1 far right)


An immersive and emotive approach has been taken with the interpretation of Huts 3 and 6. Visitors need to imagine what happened here during the war as due to the ‘Top Secret’ nature of the work little evidence survives relating to these buildings other than a few Veteran recollections and the buildings themselves. There are no wartime photographs showing the layout of the Huts.

Hut 3 'The Watch' after restoration and set-dressing
Hut 6 'The Intercept Control Room' after restoration and set-dressing

Interpretation is focussed on bringing back the atmosphere and telling specific stories in the places where they occurred: Externally Huts 3 and 6 have been restored to their wartime condition; walls have been repainted in the original palette and the blast-walls have been reconstructed. Internally, the rooms have been repainted and the paint has been ‘aged’ by a scenic-artist. Rooms are set-dressed to 1940 – 1941 using furniture, stationary, clothing, and machines that were used during the period. Blackout blinds have been reintroduced and period lighting installed. An audio track and projected figures undertaking wartime activities provide visitors with further reference points.


Underneath the temporary scaffolding roof; Hut 3 (left) and Hut 6 (right) 
The fragile instability of Hut 6 prior to restoration
Hut 6, 2013. External walls undergoing restoration: The beams were all numbered in order for them to be relocated to their original positions
Hut 6 central corridor prior to restoration
Hut 6 new floor joists being laid
The floorboards in Hut 6 had deteriorated beyond the point of conservation and restoration
Replacement floorboards for Hut 6 from wartime Huts at Fawley Court

Floorboards from historic Fawley Court, used as a Military Intelligence school during World War 2, were donated to Bletchley Park. These wartime boards from temporary Huts have provided BPT with like-for-like replacement boards for those which had rotted beyond repair.

Fawley Court also donated around fifty square metres of shiplap boarding for use on the deteriorated exterior of Huts 3 and 6.

 Hut 6 exterior cladding paint analysis cross section
Hut 6 entrance door paint analysis cross section 
Hut 6 entrance door undergoing restoration; where possible all original fabric has been retained

“The paint colours reflect their appearance originally - not aged as we often see them now - so to our perception may appear brighter than expected. However, we should remember that the Huts were blacked out and so maximum use was made of the low light levels available. The colours used were inexpensive and based upon those readily available at the time. The colour palette comes out of that previously used for service areas in large houses and interiors of workshops and factory spaces.”

Neilian (Ian) C. Crick-Smith PACR NCCR Principal Conservator Researcher & CoFounder


Hut 6 roof void where wartime documents were discovered
Wartime documents discovered in the roof void of Hut 6
Discovered items ready for remedial conservation

In 2013 during the restoration of Hut 6 the builders discovered a number of original documents within the roof void. 

These documents have now undergone conservation treatment and appear to all date to 1940 or 1941. The most exciting are two partial Banbury Sheets and a Blist.

Most are fragmented sections of larger documents that relate to early codebreaking methods and the majority appear to have been reused as scrap paper with notes written on the reverse.

"As I peered into the box of apparent 'rubbish' I felt honored to be the one to reveal their secrets…it could have been any one of those Codebreakers who last saw these documents....and now I was going to look at them, it made my body tingle all over!... I could often make neither head nor tail of their contents, but even so, I would be so careful to retain every element of originality, however 'insignificant' it may seem...”

Louise Drover Paper Conservator

Wartime Banbury Sheet
'Blist' dated 15/4/1940 

“It is interesting that the dates [of these documents] appear to be in winter months when the temptation to scrunch up a bit of waste paper and stuff it into a crack to keep out a draught would have been at its greatest.”

Codebreaker Sir Arthur Wilfred 'Bill' Bonsall KCMG CBE

'Washtub Frocks' Fashion article


Water Hall 1718 Survey
In-situ brickwork 


During trench work on the large Oval in 2014 a small section of brickwork was discovered that is believed to be part of the foundations for Water Hall, the earlier eighteenth century mansion that used to occupy the Bletchley Park site. 

Due to the importance of the trees on the Oval and the fact that a number of these have Tree Preservation Orders (TPO's) it was considered not appropriate to fully excavate the area where the brickwork was uncovered at this time.

'Rediscovery' of Huts 2 & 9 underneath later car park


During the removal of a car park adjacent to the Mansion the archaeological remains of Huts 2 and Hut 9 were discovered. These Huts were constructed in 1939 but after the war they became derelict and were demolished in 1986.

The outlines of these Huts have now been marked out with pebbles and interpreted with an external panel.


Block F was demolished in 1987 and large parts of this site are now under a modern housing estate that is still being developed. During recent work the partial foundations of this building were discovered by the developers.

In World War 2 Block F housed the Colossus machines. Colossus was the world’s first semi-programmable computer which helped to speed up the breaking of the Lorenz cipher used by Hitler to communicate with his generals.

Block F, 1980.  Spurs X, W & V
Block F foundations


The Bletchley Park Trust has a vision to become a world class museum and heritage site. The first phase of restoration was successfully completed in May 2014.  

The Trust's long term ambition is to tell the myriad aspects of the Bletchley Park story using the assets to hand: the collections, the buildings and the site itself and is currently planning the next phase of restoration to realise this ambition.

Credits: Story

Role — Gillian Mason, Curator
With thanks to the following for providing quotations and images for use within this exhibition: — Sir Arthur "Bill" Bonsall, Codebreaker; Louise Drover, Paper Conservator; Crick
Smith, University of Lincoln; Rob Davies, FWA and Peter Wescombe, Volunteer and founding member of Bletchley Park Trust. 

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.