Building materials

Overall vulnerability

Features assessed:

• Traditional roofing materials, such as stone slates and Staffordshire Blue clay tiles
• Timber-frame buildings, often cruck-framed
• Gritstone, other sandstones, and limestone, in buildings and boundary walls

Special qualities:

• Characteristic settlements with strong communities and traditions

Feature description:

Building materials are distinctive and specific to the different areas of the PDNP. Traditionally gritstone, other sandstones, and limestone have been used in buildings and boundary walls, while stone slate has been used for roofs. Traditional roofing materials include gritstone slate , stone slate, Staffordshire Blue clay tile roofs, and later Welsh slate. The vernacular architecture also incorporates distinctive regional styles. A small number of 16th century or earlier timber-frame buildings remain. Cruck-framed buildings have been found in the Dark Peak, but rare cruck-built houses and farm buildings have also been found within the White Peak.

How vulnerable are building materials?

Building materials in the PDNP have been rated ‘moderate’ on our vulnerability scale. This score is due to high sensitivity and exposure to climate change variables, but a high adaptive capacity. It is hard to quantify the current condition; however building materials are susceptible to changes in weather and fluctuations in temperature. Moves to upgrade the thermal efficiency of buildings could potentially have an impact on ventilation. This may make them more susceptible to rot and insect infestation as well as changing the character of the roof scape. Skills do exist to enable buildings to be adapted and maintained for modern living, and this can be somewhat controlled through the planning systems in place. It should be possible for the PDNP to retain its vernacular and distinctive architecture despite climate change.

Current condition

Due to the diverse nature of this category and the limited information available it is hard to quantify the current overall situation. As an example, there has been some erosion at low levels on some of the historic buildings within the PDNP such as a number of historic buildings in Bakewell built from finer grained sandstones. This is predominantly at ground level and may have been caused by dissolved salts used on the highway or other contaminants associated with roads. Loss or degradation of traditional building materials has also been associated with dereliction of properties (see ‘Farmsteads’ and ‘Field Barns and Outfarms’ feature assessments for more information) or by installation of non-traditional materials as buildings are ‘upgraded’ or adapted.

What are the potential impacts of climate change?

Overall potential impact rating

Direct impacts of climate change

Climate change has the potential to impact the building materials that dominate the PDNP landscape. Many materials are sensitive to fluctuations of temperature, and to greater extremes of temperature, as this increases thermal expansion and contraction of wood, stone, metal, paint and lead. This may lead to accelerated attritional damage of building materials. Data Certainty: Moderate

Wet masonry and other building materials such as mortar are sensitive to frost especially repeated freeze-thaw and may be unable to cope with additional rainfall and higher intensity. This could damage masonry, slates and other building materials. Data Certainty: Moderate

Extreme events are likely to increase the damage by flooding (both from rivers and surface water); roofing materials can be damaged by high winds associated with storms while periods of sustained rainfall may cause waterlogging of the ground around buildings. Data Certainty: Low

Wetter winters and the expected increase in storm events would mean that water ingress could become more prevalent, particularly if structures have not been maintained well or adapted increasing their susceptibility to damage. Data Certainty: Low

Invasive or other species interactions

Increased annual averages and wetter warmer winters could see an increase in mould growth within and algae outside buildings. Building materials are sensitive to structural damage from any increased growth of plants and in particular insect pests, rot and fungus in wooden framed structures. Physical damage to building material may then require intrusive renovation work to be carried out. Data Certainty: Low

Increased carbon dioxide levels and other atmospheric changes may impact on invasive or nuisance plant species for example by increasing growth rates in Japanese knotweed, or trees and shrubs which can cause physical damage to building materials. Increased flooding events may increase seed dispersal of riparian invasive species. Data Certainty: Low

Human behaviour change

Moves to upgrade the thermal efficiency of buildings as climate change mitigation, by increasing insulation and installing solar panels on roofs, can have a negative impact on the building and roofscape but not necessarily on building materials. Decreased ventilation may increase rot of wooden structures and increase the likelihood of insect infestation. This in turn could lead to deterioration in wooden framed buildings and slate or stone roofs supported by wooden battens - which could lead to change in the character of the PDNP roof scape. Data Certainty: Low

Some traditional materials and building components (e.g. windows) may be less suitable for withstanding extreme events if not maintained and there may then be pressure to upgrade buildings with modern materials. The character of buildings in some areas may change and look less traditional. Data Certainty: Low

Sedimentation or erosion

The cracking of the ground in hot drought periods makes building materials susceptible to damage and the overall long term robustness of structures can be compromised. Data Certainty: Low

Increases in periods of drought are likely to increase the impact of this process leading to the need for major structural repairs in places. Some types of stone are sensitive to erosion from acid rain which may cause damage to building materials, Data Certainty: Low while wetter winters may see traditional building materials subject to an increase in erosion by hydraulic action. Data Certainty: Low

What is the adaptive capacity of building materials?

Overall adaptive capacity rating

The planning system in place in the PDNP means changes to building materials and adaptations can be well controlled in most circumstances, but not all. Adaptations may have to comply with building regulations which could result in the loss of historic features or character. For unlisted buildings there is more limited planning control. Data Certainty: Very High

There is a good level of information about what assets exist, and the skills and techniques exist to adapt and maintain buildings in order to offset many changes in climate. Traditional buildings are already being adapted for modern living within guidance and with the special qualities of the PDNP in mind. However, there could be a lack of financial incentive to maintain or restore materials in some settings - an example being field barns which are mostly redundant for modern farming although can sometimes be re-used for other purposes. Data Certainty: High

Most traditional building materials examined here are inherently robust and resilient, with wooden structures likely to be the most vulnerable to climate change. Leaded windows may need repairing more. It is possible to repair damage whilst maintaining character and historic significance, as long as economic resources and materials are available. Data Certainty: Low

Availability of economic resources depends on status of building, such as its historical significance, and the ownership. There are generally few resources available and these will be for some but not all buildings. Data Certainty: Low

Materials are used in a wide variety of situations across the park - and a diversity of materials is to be found in different locations. It is likely that the PDNP will retain its vernacular and distinctive architecture despite climate change. Data Certainty: Low

Key adaptation recommendations for building materials

Improve current condition to increase resilience

The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations are aimed at improving the condition of the feature at present, therefore making it better able to withstand future changes to climate.

• Provide good information on appropriate materials and encourage building owners to carry out timely maintenance and repairs.

• Create/maintain strong partnerships with external organisations to highlight materials sourcing issues, and ensure steady supply of appropriate materials (e.g. Historic England, minerals operators, architects, tradespeople).

Adapt infrastructure for future conditions

These recommendations are adaptations to physical infrastructure that should allow the features to better resist or recover from future climate change.

• Keep abreast of new research into the performance of alternative materials for future climate adaptations.
• Encourage the use and benefits of traditional materials. Review building design with the impacts of climate change in mind.