Do you hate the grey concrete of the University of Durham’s 1960s student union building, Dunelm House? If you feel the same wincing hostility towards the grey concrete dome of the Roman Pantheon, then fair enough — I cannot help you.

If, however, you admire the Pantheon but dislike the best Brutalist architecture, you are missing out on some wonderful buildings. And no one should forego new pleasures willingly.

The tag “Brutalism”, widely used for 1960s concrete Modernism, may not endear the style to you. It is a jokey nickname that stuck. Yet it captures the power of the architecture. In architecture, as in nature, there is space for the magnificence of snorting, stamping bull elephants such as Dunelm House and Durham Cathedral, as well as for mousey cottages and improbable, impractical birds of paradise such as the Taj Mahal. If awe-inspiring sublimity was OK for Michelangelo and Hawksmoor, why was it suddenly an affront to the public realm when done by twentieth-century architects?

Dunelm House is ruggedly assertive in its unapologetic concrete, its confidently blocky massing offset against sloping mono-pitch roofs, and its satisfyingly chunky rainwater gargoyle. It is a fittingly muscular celebration of the moment when British universities expanded to allow the best students from all social backgrounds to have access to higher education.

Some mistake its toughness for hostility, its directness for lack of care. Others even oppose the construction of unabashedly modern buildings in a city with prominent older architecture. This is absurd. Why should designers ape the styles and materials of the past when using building and servicing technologies that have changed beyond all recognition? Do these fanatics also demand fibreglass horses on the front of their cars?

A suburban middle-class child of the 1980s, I once hated Brutalism, too. But since looking at it properly, I have spent 20 years loving and defending it. Its best buildings need your sympathy and support. They are as vulnerable to demolition now as Victorian buildings were in the 1950s: being out of fashion makes their large sites a soft target for lucrative redevelopment. Despite noble campaigns by the Twentieth Century Society and others, we are losing many of the best buildings of the 1960s, or seeing them altered to the point where their original qualities are destroyed.

Dunelm House is under immediate threat.

In its current sad state, it takes an expert eye to spot its underlying beauty. Successive student union committees have rushed to make their mark on it, year after year, on a low budget: fake grass on the balconies; awful paint-jobs to “cheer up” the interior; superabundant, clashing signage; nightmarish herds of chirpily bright, mismatched furniture jostling unmajestically in the common rooms. New cables snake over once-elegant walls like varicose veins. Speakers, noticeboards and light fittings have everywhere been added cheaply and expediently. There is no sign that the installers had a sense that there was even anything to respect, let alone knew how to respect it. I defy Durham Cathedral itself to survive such treatment with dignity and grace.

Outside, Dunelm House’s concrete is shabby in places, which many find much uglier than shabby stone. Like stone (which is what concrete is made of, of course), it can gradually change colour or accrue damage over decades of weather and use. Like stone, concrete walls enclosing heated interiors age much more slowly, remaining light-coloured and clean whilst cold walls grow lichen, and darken with watermarks that many who dislike “streaky concrete” would find beautiful on a cliff.

Like stone, if you cut out damaged areas and replace them using expert craft, the wall will last a very long time. Dark rumours of a condition called “concrete cancer” are spread by contractors pitching for repair work, and by developers using fear and exploiting technical ignorance to push controversial but profitable demolitions. Perhaps they should also describe flaking paintwork as “wall leprosy”.

Nevertheless, if Dunelm House is compromised inside and shabby outside, might it just need to go, whatever its original qualities? Emphatically not. If the will is there, it is an easy and delightful job for a good architect to scrape back Dunelm House to its beautiful bones, to give it long-needed, sensitive maintenance and to upgrade its facilities whilst restoring its original sublimity. Several prominent practices have already proposed plans for refurbishment and reuse.

Despite much bluster to the contrary, reusability has more to do with taste than with technical challenges. Purpose-built 1960s buildings are frequently demolished for practical shortcomings far milder than those of the barely-converted Georgian houses into which departments of Durham, London and Liverpool universities proudly but inefficiently contort their activities. Durham and other universities hide behind claims of inflexibility to justify their architectural prejudice against Modernism, and perhaps also a lust for shiny new buildings to attract donors and give glamour to next year’s prospectus.

What, then, is Durham is failing to see in its wonderful building?

The most prominent and beautiful feature of Dunelm House is also the one that attracts most hostility: its concrete. Again, Victorian architecture has been through this cycle of fashions before. When Butterfield’s glorious Keble College, Oxford, was new a student society of its detractors rewarded members for wrenching bricks out of its walls, yet they are now its loved defining feature. A joy of medieval and Arts and Crafts architecture was the record left by chisels and saws on the finished surface, unlike the sleek sheet claddings that make many new buildings so anodyne. Looked at closely, concrete tells more stories than stone. Each long-gone wooden board of the formwork moulds is memorialised by its imprint on the finished concrete. The subtly varied textures and colours recall the slight natural variations in the sand, gravel and cement.

For dunelm house, concrete is perfect: neutral enough to make shapes and spaces speak for themselves, honest in showing how it was made and what it is made of, tough enough to survive many decades of rough student wear, and stony enough to rhyme with the cathedral just across the valley.

Beneath this expressive and robust surface, the structural brilliance of concrete and steel was an inspiring liberation to architects. Concrete is stone-like in its appearance, and behaves like stone technically (strong in compression, weak in tension). Because it can be reinforced by steel cables that run through it, however, it is the most powerful and versatile building material ever seen. Ancient Egyptian architects, despite their fondness for moving very large single pieces of stone, would have gasped in wonder at the ability of concrete to produce an entire building structure as a single vast, complex-shaped piece.

Masonry walls had to rise vertically, each brick or stone landing on the ones below. Architects then decorated the largely flat surfaces that resulted. Reinforced concrete allows architects to compose their buildings like sculptors instead. If what you like is the abundance of almost two-dimensional classical details in Somerset House’s stonework you will miss it at Dunelm House, but if you like the sculptural forms that Hawksmoor or Wren worked so hard (and spent so much) to force from the intractable brick and stone, the burst of excited exploration of building shapes that characterises 1960s architecture will lift your heart.

What Dunelm’s wonderful architects, Architects Co-Partnership, did with their new freedom, like so many designers of the period, was to relate the building carefully to its surroundings. They did this not by slavishly copying older neighbours, apologising for the new building’s existence. Why should they? It was a wonderful new set of facilities for a generation of students whose futures looked exciting and expansive. Why should it look superficially like a Georgian house?

Dunelm house turns its back on the growing motor-noise and pollution of 1960s roads in favour of the glorious wooded valley of the River Wear. It shelves down the steep slope from street to river like an Italian hillside village, allowing from outside and inside sudden glorious framed views of river, trees, and the magnificent cathedral that dominates the skyline. Its respect for Durham’s heritage is shown not by half-hearted copying but by keeping its roofline low, so that it never competes with the medieval roofscape of cathedral and castle.

Inside, the many different sizes and types of room (everything from boat stores for the rowing club through to offices, bars and flexible event spaces) come off a single broad stairway, descending in stages, with ample leftover space around the actual pedestrian route for the informal encounters and incidental pleasures that define the student experience — a few moments reading a book, or a passing hello that blossoms into 15 minutes of conversation and thence a lifelong friendship.

University managers now borrow from speculative office planners space accounting techniques that condemn such unprogrammed spaces as wasteful. Let us hope they never apply such metrics to Oxford’s beautiful Radcliffe Camera, whose fabulously prodigal volume houses so few desks and books.

The larger rooms at Dunelm House use the wide spans easily achievable with concrete and steel to allow column-free flexibility for a vast diversity of uses, but avoid the potential blandness of big open spaces through the use of glamorously sci-fi swooping ceilings and windows that frame beautiful views.

Britain’s burst of High Brutalist university building in the 1960s was one of the great construction booms in history for imagination, optimism, conviction, aesthetic strength and technical achievement. Dunelm House was among the major achievements of that boom. Learn to love it, and quickly —
unless Durham University comes to its senses, it may not be there for long.