NEW environmentally friendly methods for laying housing foundations on peatland could help economic development in parts of the Highlands and islands, it has been claimed.

A research consortium led by Edinburgh Napier University and Heriot-Watt University is assessing the feasibility of a range of construction methods to minimise disturbance to peat in areas where its presence currently limits building options.

The research is supported by the Scottish Government, Highland Council, Highlands and Islands Enterprise (HIE), Construction Scotland Innovation Centre (CSIC), JAHAMA Highland Estates, the Scottish Environment Protection Agency (SEPA), NatureScot and ECOSystems Tech Ltd.

Peatland plays an important role in Scotland’s natural landscape and ecosystem, comprising dead and decaying plant material with carbon captured in the remains.

As much as 20 per cent of Scottish land is covered in peat soil, which serves as a significant carbon store for more than 1.7 billion tonnes of carbon–equivalent to 140 years’ worth of Scotland’s total annual greenhouse gas emissions. However, the soil is often unsuitable for building on because of low strength, landslide risks and its tendency to deform under load.

In parts of the Highlands and islands, where peatland is commonly found, new housing is in short supply, and some sites targeted for development are complicated by the presence of peat.

Finding viable, sustainable methods for building on peatland that align with restoration work already under way could transform Scotland’s approach 
to rural housing, however.

It is claimed good quality, affordable homes could help to reverse population decline and promote economic growth in rural areas, encouraging a young and talented workforce to move to and stay in the Highlands and islands.

Construction teams have previously relied on excavate-and-replace techniques, but the new project will explore a number of options that allow peat to be left in place, such as deep-soil-mixing, and piling.

Timber piling would use tree trunks or long poles of timber to carry the foundations of a building. Disturbance of the peatland would be minimised, especially the presence of groundwater, which is essential if peat is to continue to accumulate.

The aim of the first phase of the project is to assess and compare the geotechnical suitability, environmental impact, logistics and cost implications of the different approaches. In a second phase, live field trials are planned to assess the suitability of proposed solutions.

The research is supported by the Scottish Government, Highland Council, Highlands and Islands Enterprise (HIE), Construction Scotland Innovation Centre (CSIC), JAHAMA Highland Estates, the Scottish Environment Protection Agency, NatureScot and ECOSystems Tech Ltd.

Dr John McDougall, of Edinburgh Napier University, said: “Peatland has long posed a challenge to construction, the solution to which has commonly been an aggressive practice of removal.

“More recently, planners, environmental agencies and engineers have become increasingly aware of the very significant role of intact peat in the carbon cycle. In this context, it is exciting to be leading a re-evaluation of foundation options in the context of geotechnical, environmental and economic factors.”

Councillor Trish Robertson, chairwoman of Highland Council’s Economy and Infrastructure Committee, said: “Highland Council is happy to support this research project as a way of exploring innovative ways of achieving our objectives of delivering more affordable housing and inclusive economic growth, while safeguarding better croft and other agricultural land, and reducing the carbon emissions presently caused by development on poorer agricultural land, which often contains significant peat deposits.”

“I am hopeful that the results of the research can have a practical application for future developments and help us even better achieve our objectives.”

Scott Dingwall, head of regional development for Lochaber, Skye and Wester Ross at HIE, said the availability of suitable affordable housing was a key factor in development across the Highlands and islands.

He added: “This innovative project has the potential to make it feasible to develop housing in areas where it previously would not have been considered. This could benefit rural economies and strengthen local communities, while protecting some of the region’s outstanding natural features.

As such, it could be a key element in our shift towards a carbon neutral economy and achieving our net-zero targets.”

Andrew Nurse, project manager at CSIC, said: “In line with Scotland’s goals for net-zero, especially in the construction sector, we are looking at more sustainable options, such as timber piles, as a solution for building on peatland that could also make use of local, home-grown materials. 

“Once we have reached conclusions from the feasibility study, the next 
stage will be to conduct a series of on-site trials.”