Now nearing completion, it has taken the National Trust seven years of painstaking work to list all the buildings which pre-date 1898. Of those, surveyors estimate that at least three-quarters of them are still recognisable while about a quarter listed on the original ordnance map of 1898 have disappeared completely.

Few would deny that the mammoth task undertaken by the Trust is a vital one.

The realisation that the Island's unique architectural heritage is one of its greatest assets takes on even more significance in these days of conservation awareness, to say nothing of cultural tourism.

Bermuda has some of the very oldest buildings in the western hemisphere. Yet, incredibly, there is still no legislation which protects this priceless heritage, an omission which, many would agree, has long been in need of remedy.

The urgency in redressing this omission has been brought dramatically home just this week with the news that Overbay, one of the few remaining old 19th century homestead buildings on the Hamilton end of Pitt's Bay Road, is be torn down to make way for yet another office block. This week, Overbay, next week -- who knows? With this exhaustive survey, the National Trust has taken a giant step toward rectifying this unacceptable situation. Now, for the first time, the Island has an inventory of its architectural heritage.

And as the overall survey reaches completion, a series of books highlighting Bermuda's Architectural Heritage is planned. Each book will represent a different parish. The first will cover Devonshire, listing all of that parish's architecturally and historically notable buildings. The text is to be written by local architectural expert Mr. Andrew Trimingham and it is hoped that the first issue will be published before Christmas.

Mrs. Rosemary Clipper and Mrs. Margaret Lloyd have headed up the National Trust survey team which, over the years, has involved over 100 volunteers.

Mrs. Clipper says it was visiting consultant Professor Carl Feiss, invited here by Mrs. Joyce Hall back in 1978, who advised that the most urgent task facing the Trust was to do a stock-taking, so as to establish precisely what historic buildings actually existed.

Mr. Trimingham and Government archivist Mr. John Adams both felt that the best way to achieve this was to conduct a detailed, parish by parish survey.

Once this had been agreed, Mrs. Clipper and Mrs. Sylvia Shorto devised a form which was then given to the teams of volunteers as they visited properties all over the Island.

Says Mrs. Clipper, "The idea was to visit all the buildings listed on the map. Mercifully, at that time, we had no idea how many were still standing.'' Asked why the cut-off date of 1898 had been used for the survey, Mrs. Clipper explains that this was the date of Lt. A.J. Savage's "excellent'' ordnance map. "He was attached to the army at Prospect and he really did a very good job. He even drew the correct shape of the buildings -- quite a feat, working on such a small scale.'' They then took the information on this map, which had a scale of six inches to the mile, and tackled the huge job of transferring it to the 1984 ordnance map, which is 25 inches to the mile.

They were greatly assisted, says Mrs. Clipper, by Mrs. Shorto's visit to Rhode Island to see the re-survey undertaken by that state's Preservation Commission.

"The difference between their survey and ours was that they were using professionally trained staff. Sylvia was able to bring a lot of useful information back with her. But basically, we learned as we went along,'' she adds.

Mrs. Clipper and Mrs. Lloyd stress that the 4,000 figure includes all buildings, some of which may be small, modest structures.

"They're not all houses, either,'' adds Mrs. Lloyd. "We have also surveyed churches, shops, warehouses and outbuildings. A lot of the houses are small, modest buildings. Quite often, they don't survive as well and often have extensions built on. And farm buildings may not have been built with the best building materials, so in some cases they haven't lasted as long as might be expected.'' Admitting that the historical research on just one building could "go on forever'' the team decided to concentrate primarily on the architectural features rather than historical associations for both the survey and the book.

"Otherwise you just get bogged down because the history of a place can be so fascinating,'' explains Mrs. Clipper.

Says Mrs. Clipper, "the whole process has been a long one because it involves quite specialised knowl edge. For one thing, you have to know how to use the Archives, to jump from one Bermuda reference book to another, and be tenacious enough to read old wills and church records to try and discover how the deeds were passed on in the event of marriage or death, for instance. It's a bit like a detective story where you piece together clues as you go along!'', Paying tribute to the volunteers, Mrs. Lloyd says, "they worked like beavers, doing the original visits all over the Island with the original form we had made up. Now we are going back, visiting every single property with an improved check-list to ensure that all the information is as accurate and detailed as possible.'', The process includes taking contact photographs of each property (all of which now repose in the Government Archives for use by future researchers), with the check-list noting period or style, present use, with a general description, such as the number of storeys, roof design, gables, walls, chimneys, outbuildings, and a note of alterations and whether they are good or poor. Any perti nent historical notes are also jotted down on the form. All of this information is now being computerised.

Both Mrs. Lloyd and Mrs. Clipper have been pleasantly surprised by the reception they have received on their treks round the Island. Says Mrs. Lloyd, "Nearly all the people we have visited have been very nice about it. One or two were a bit suspicious at first, but we explained we only walk around the outside. A lot of people insisted that their house was at least 300 years old!'' One of the biggest surprises of their inspection was to discover how many beautiful old buildings still exist in Hamilton, especially in the `back of town' area.

On the debit side, the survey has increased their alarm over the fact that irreplaceable buildings are being knocked down, and that there is no control over outside alterations.

Says Mrs. Lloyd, "Of course we all understand that people need to improve the interiors of many of these buildings, and to modernise. But no attention is being given to what the house looks like from the outside. So you get a beautiful Georgian house with louvre windows or doors, the blinds removed, or even doors re-positioned which totally destroys the symmetry of the building.'' Now, these dedicated chroniclers of Bermuda's past are hoping that heightened publicity, such as the publication of the parish books will help Bermudians to realise that their old homes are, in fact, precious heirlooms.

MAYFLOWER MEWS -- This gem of Bermudian architecture, situated in the grounds of Mayflower in Devonshire, was built as a dwelling house around 1700. Owner Mr. William Cox says the building was used as a home until well into this century.

PALMETTO HOUSE -- One of Devonshire's loveliest old homes and a property belonging to the National Trust, Palmetto House is thought to have been built in the early part of the 17th century.

GOSPEL CHAPEL -- The North Shore Gospel Chapel on Glebe Road was built in the 19th century.

DEVONSHIRE HOME -- This Georgian-design dwelling house is situated on the North Shore. As with many smaller homes, the room on the left was obviously added on at a later date.