THE view from atop the “mother of parliaments” is not as uplifting as it might be. Gutters collect smelly pigeon carcasses half-chewed by the peregrine falcons that nest there. Three years ago a rooftop water tank collapsed, flooding the corridor below and drenching valuable paintings. The stonework looks more medieval than Victorian, so worn is it. To the north, the clock tower popularly known as Big Ben leans by nearly nine inches (22cm), rattled out of place by the Jubilee Line running beneath.

Most of the Palace of Westminster was built in the mid-19th century after a fire levelled its predecessor. It has survived the Luftwaffe, smog and acid rain. Not once has it been comprehensively repaired. During parliamentary recesses armies of workers hurriedly patch leaks, cracks and tears. But the edifice is now decaying faster than it can be fixed. The architect responsible for its conservation, Adam Watrobski, reckons that chunks are on the verge of dropping off, hazarding the MPs, staffers and—God forbid—journalists who scurry across the courtyards below.

With this year’s summer recess approaching, the latest round of works is gearing up. But so too is a grander plan to sort out the building’s problems. In 2012 parliamentarians commissioned a study of them. Its findings were grim. “If the palace were not a listed building”, it concluded, “its owners would probably be advised to demolish and rebuild.” Convinced that something must be done, palace officials have appointed consultants to flesh out modernisation proposals. In the next parliament, beginning in 2015, MPs and Lords will have to decide whether or not to authorise one of the three plans that are under consideration.

Two of them involve partially or fully relocating Parliament during repairs. A confidential list has been drawn up of sites close to Whitehall that could be adapted for parliamentary business. Options might include the nearby Queen Elizabeth II Conference Centre or County Hall; farther afield, the Excel Centre in east London might suit.

The decampment could last five years, as the repair job will be enormous. One priority is the roof. White stains, a product of rainwater from above and vapour from the crowds below, gild the ceiling of Central Lobby, the vast chamber between the lower and upper houses. The pre-war steam-heating system reaches only 30% of the rooms in the palace. Some are freezing in winter and stuffy in summer. Others have no smoke detectors. An urban fox is known to wander the stairwells at night. New MPs are often keen to have an office in the palace, but wiser ones invariably head across the road to Portcullis House, a modern building that opened in 2001.

Beneath contempt

Many of the biggest problems lie under the surface. The palace has 444 miles (715km) of wires and about 17 miles of pipes, many in the enormous basement. The wiring was installed bit by bit, and it shows. Masses of lines carrying electricity, division announcements, phone calls and broadcast feeds (plus a dusting of asbestos) are slung from water and air trunks like creepers along the branches of a tree. “I’ve been chasing them for two years,” groans one workman in a hard hat, ducking under a tangle. Some are almost completely inaccessible, impeding repairs. A fury of 1950s telephone wires pinned to one corridor wall remains a mystery to engineers. Some, they reckon, connect lost speakers in one part of the building with lost receivers in another. Revamping the lot will be a mammoth task.

The lack of maps will make it even bigger. No original drawings by Charles Barry, who designed the 1,100-room palace after the fire in 1834, survive. The authorities are constantly adding to their plans as new chambers and vents are discovered. Some cavities turn out to house families of mice, for whom the building is a perfect home (by the river, with warm nooks and lots of food sitting around). Others hide treasures. Under one flagstone, workers recently discovered remains of the bench at which Londoners stood to petition kings nearly a millennium ago.

The building is not unique in its creakiness. Thousands of British churches, stately homes and monuments are in a similar state. Like many of them, the palace is listed. An on-site archivist polices changes to its appearance. But unlike most other such buildings it is also a bustling workplace. Reconciling its modern functions and its historical integrity (or “the tactile and the contemplative”, as Mr Watrobski puts it) poses particular challenges. Hundreds of leaded windows do not close properly, creating draughts and security risks. But they cannot be replaced by efficient modern ones, which would look out of place.

A serious programme of repairs will be hard and expensive. Parliamentarians, when they come to vote on the proposed changes in the next parliament, will therefore face a choice between three deeply unappealing options. They could disrupt their work by moving out during repairs. They could stay put, making the process unnecessarily slow and inefficient. Or they could do nothing much, and watch the palace crumble around them.

Commons authorities are trying to concentrate minds, but so far only one in ten MPs and lords have taken up their offer to tour the building’s clapped-out corners. Perhaps take-up will increase when something grinds to a halt: the ventilation system, perhaps, or the heating. Far be it from politicians to forgo hot air.