MAJOR repairs to Helensburgh's leading visitor attraction are likely to cost millions of pounds.

But contrary to some media reports, there's no prospect of the Hill House being sold or leased by its owners to become a hotel.

The National Trust for Scotland, however, says a public fund-raising campaign will be needed to help meet the cost of the Hill House repairs.

The Charles Rennie Mackintosh property, in Upper Colquhoun Street, has suffered from the effect of moisture penetration through its external plasterwork ever since its completion in 1904.

Media reports last week suggested that the Trust was considering selling or leasing some of its properties as part of a major restructuring programme, in a bid to cut running costs and tackle falling visitor numbers.

But NTS spokesperson Jim Whyteside told the Advertiser the Hill House would not be sold or leased – or, as suggested in one report, turned into a hotel.

Mr Whyteside said such suggestions were “untrue”.

“The Hill House is clearly a place of the highest cultural significance, and must be well cared for,” he said.

“Over the years many attempts have been made to deal with the problem with some degree of success, such as re-roofing and reinstatement of lost features. These works represent over £100,000 of investment.

“However, it has become apparent, especially with the trend towards windier and wetter weather, that a more radical solution is needed.

“While we seek this long-term solution, we are looking at possible ways to prevent further water ingress and undertake a controlled process of drying out the structure prior to applying a new formula of harling.

“Possible options are due to be discussed by the NTS Board of Trustees at their scheduled meeting in late October.

“The cost of this longer-term solution is likely to run into millions of pounds. We have had a good start, with the philanthropic Getty Foundation allocating a grant of £95,000 towards the conservation works.

“The award comes through the Foundation’s ‘Keeping it Modern’ architectural conservation grants scheme.

“Going forward, we will be designing a fundraising campaign to provide the resources needed for the main conservation works.”

According to figures from the Association of Leading Visitor Attractions, 25,340 people visited the Hill House in 2015 – an increase of 8.5 per cent on the previous 12 months.

Architect and Hill House designer Charles Rennie Mackintosh dispensed with many techniques normally used to protect buildings from the effects of bad weather, such as projecting chimneys and skew copes, in order to achieve his aim of a house devoid of “adventitious ornamentation”, hoping instead that a cement-based harling – in those days a relatively untried technique – would weatherproof the most vulnerable areas of the building.

Mt Whyteside continued: “Despite numerous attempts since its completion to minimise ingress, including several large-scale repair projects, continual ongoing maintenance and monitoring, and a plethora of specialist reports, external harling failures and outbreaks of dry rot internally signal that an inherent problem still exists today.

“Previous repair approaches at the property have been the subject of much debate, having gone from an invasive approach of stripping and re-applying ‘like-for-like’ cement-based harling over a new and/or consolidated masonry/brick background, to a more conservative approach based upon retention and consolidation of surviving finishes.”

In response to media reports of a funding crisis at the NTS, Mr Whyteside said there were “no 'cuts' as such”.

“What we are talking about, through organisational changes, greater efficiencies and re-deployment of existing funds, is to invest £17 million in the next 3–4 years in what we are calling ‘priority properties’," he said. 

“These are properties that we have judged to offer the most potential to attract visitors and members again in numbers last seen around a decade ago.

“The additional annual income more members and visitors will generate, along with freed-up resources from ongoing efficiencies, will then be re-invested in the entire estate, so that all of our ‘inalienable’, visited properties will eventually benefit. 

"We have estimated that we need to invest £47 million across our estate to deliver the standards of conservation we aspire to, and the new strategy is aimed at kick-starting the process and taking a serious bite out of that figure.

"In the interim this does not mean we will stop caring for the properties not deemed as ‘priorities’ for the time being. They will still be exceptionally enjoyable and significant places to visit. 

"The real differences will come a few years downstream when we finally have the wherewithal to fund our conservation ambitions.”

Stewart Robertson, director of the Charles Rennie Mackintosh Society, a non-profit charity set up in 1973 to promote and raise awareness of Mackintosh's work, said: “We're very keen to see long-term repairs carried out at the Hill House as soon as possible.

“Both we and the Trust know what the problem is – it's just a question of having the funds to carry it out – but if significant repairs aren't carried out quite soon you'll start to see major problems with some of the internal features of the house, such as some of the stencilling and wall coverings, which are irreplaceable.”