Archive for category: News

Old v. New Heating Strategies

Older buildings were constructed as a cellular arrangement of rooms that would be individually heated as and when they were being used. In comparison, modern heating strategies use electronic controls to tailor the heating in the house to your exact preference. It is also important to consider the difference in building materials used in the construction of old buildings compared to the present day. These materials may not necessarily be compatible to use together, for example, the very hard material of concrete may damage the softer materials of the older building.

The older houses were built with the principles of using traditional methods of retaining heat, for example:

• Closing heavy curtains
• Shutting internal doors
• Closing shutters at night
• Utilising the thermal mass of the structure to retain heat from fires and slowly release it over a longer period of time

Nowadays houses are built with heating features such as insulation, electronic heating system and waterproof cladding.

Insulating historic buildings

The insulation of historic buildings is one of the most important aspects to consider when upgrading the infrastructure of an old building. Traditionally, older buildings have solid walls, whereas newer buildings tend to have cavity walls

A cavity wall is a wall formed of 2 separate walls (usually brick and block) with a space between them. Insulation is fitted in the space between them meaning there is one “wet” wall, on the outside of the building, and one “dry” wall on the inside of the building.

Older buildings don’t have this cavity insulation, the walls allow a degree of moisture penetration into their structure but avoid damp problems due to the breathable nature of the materials used, for example renders based on lime, earth or clay and finishes such as lime wash. These materials absorb water, but also allow for easy evaporation.

Therefore, using modern construction methods such as cement-based materials, ‘plastic’ paints and waterproof sealants will not be effective on an older building and could damage the walls of the property.

Natural insulation materials tend to be much more breathable than synthetic materials and therefore will be more effective and less damaging to use on an older building. They act as moisture buffers and tend to “breathe” with the original walls of the building. Examples of these natural materials include wood fibre, hemp, sheep’s wool, cellulose, aerogel, calcium silicate and many more.

Sheep’s wool insulation

These materials will also have excellent sustainable properties, such as:

• Low embodied carbon
• They improve indoor air quality
• They are easy to recycle at the end of their life

Tips to make your building more energy efficient

When making historic buildings more energy efficient there are some simple things that you can do to begin with, that a relatively inexpensive and are less likely to cause problems with the structure of the building itself.

• Fit draught excluders to letterboxes and outside doors

• Invest in heavier curtains

• Ensure that radiators aren’t blocked by furniture

• Mend any broken windows

• Fill in any gaps in wooden panelling

• Get LED lights fitted

• Clear out the gutters and the drains (these make the walls cold!)

More expensive methods that would be the next step up from this would be:

• Installing programmable thermostats
• Make sure all the heating and hot water pipes are well insulated
• Wood burning stoves fuel much more efficiently than open fires and cause fewer draughts

Incorporating environmental and sustainability measures into buildings is an essential part of good design and allows new construction to refresh old and so that buildings will stand the test of time.

Hunsett Mill is located in the heart of the Norfolk Broads, a man-made wetland sustained through human intervention and the building of water-pumping mills, dykes and canals. It is an example of an older building that become redundant due to the introduction of electric pumps.

Here are some examples of how the site become more sustainable:

• Construction of a new embankment at the back of the site has returned the nearby forest and grassland to pre-industrial marshland conditions
• Indigenous plants were placed in the garden to enhance the local ecology
• Site damage during the construction of the new extension was mitigated through careful design and material choices that reduced the amount of heavy machinery that was required

The nature of older buildings means they are already sustainable in their own right. For example, the materials they are made of are often locally sourced and produced and can be easily recycled or re-used at the end of their life.

Another example of where sustainability can be incorporated into older buildings is the additions of green, or living roofs.

A green roof is a system that uses vegetation as the finish of the roof covering instead of just the weathering materials. 

What are the benefits of a green roof?

• Helps to reduce the water run-off from buildings
• Filters pollutants
• Increases biodiversity and provides a habitat for wildlife
• Improves thermal and acoustic insulation
• Helps the building blend in with the surroundings

A great example of one of our past projects incorporating a living roof is Dunsford House, pictured below. The roof line was designed to mirror the angle of the sloping ground. The NatureMat was particularly suited to low pitched and curved roofs and restored the green natural environment with a composite vegetated mat with a 90% mature plant cover comprising 6- 8 species.

We think that Roger Hunt summarises incorporating sustainability into old buildings rather well – “To make our old buildings sustainable, compromises are inevitable but we can’t simply wrap them in thermally efficient, airtight membranes and ‘duvets’ of insulation and hope for the best.” It is important to come up with effective solutions to slightly challenging problems so that old buildings can be enjoyed for many generations.