They are the architectural treasures you glimpse out of the corner of your eye as you’re driving through the countryside or walking through town.
But hundreds of them are being allowed to fall into ruin.
Ulster Architectural Heritage Society (UAHS) has listed its ‘dirty dozen’ — the worst of the more than 500 once-beautiful buildings scattered across Northern Ireland deteriorating through lack of maintenance.
While Northern Ireland Environment Agency can order owners to repair listed buildings, these have only been used in two cases in the last 10 years.
This week is National Maintenance Week and UAHS has issued advice for owners of listed buildings on how to prepare their property for winter.
It said that if owners undertake straightforward maintenance measures in autumn, it can prevent major faults and damage at a later date, and stop buildings from being “at risk”.
The biggest enemy of building fabric is water, but an annual cleaning of gutters and drains can be cheaper and less traumatic than having to cope with dry rot after years of neglect, said UAHS director Rita Harkin.
“Ten minutes spent outside on a rainy day checking the performance of your gutters and drains can really make a difference. Just a few minutes invested in clearing weeds and debris, or just a few pounds to mend a leaky gutter can save many hundreds, and possibly thousands of pounds,” she said.
The society suggests checking for blocked downpipes, clearing debris from gullies, drains, hopperheads and flat roofs and removing damaging vegetation from downpipes. You can use a hand mirror to check for hidden cracks behind rainwater pipes.
Owners should fit guards to soil pipes and rainwater outlets and have gutters refixed if they are discharging water onto the wall. Regular painting of cast iron is essential to n prevent rust.
More advice, including the leaflet Look Before You Leak, is available at www.uahs.org.uk/resources