top of page

Improving Thermal Efficiency in Historic Buildings

With winter right around the corner, for those who live in historic properties, they only know too well the preparation and strategies they will need to start implementing in order to maximise thermal efficiency and keep their home warm as well as free from damp, draft and condensation.

Unlike modern buildings, historic properties were not as well-designed to control the movement of moisture and air as often, the chosen construction material takes up moisture from its surroundings and releases it according to the environmental conditions. This means that you many have noticed your historic property taking longer to heat up and cool down when compared to their modern counterparts.

Given the current energy crisis, how we manage to heat old buildings this winter will inevitably change as for many, keeping the heating on will not be an option. Therefore, it is vital that your home can achieve good thermal performance. This can be achieved through a number of ways. It must be noted that should your building be listed, you may be required to apply for Listed Building Consent prior to undertaking some of these works.


About one-fifth of a home's heating is lost through windows, most of which escapes through air gaps in the frame as opposed to through the glass. If windows are left in an unsuitable condition, water, condensation and draughts will enter your home, and potentially be the catalyst for a damp issue. As such, one of the first areas to look at when improving your home’s thermal efficiency is the windows.

Should your historic house be classed as either a designated or non-designated heritage asset, Historic England encourages restoration over replacement. If your windows are in need of some restorative works, then the sensitive repair of targeted problem areas is more likely to gain listed building consent and may also prove to be the most cost-effective option when improving the quality of windows within your home.

If your windows are single-glazed, you may wish to look at either secondary glazing or inserting double glazing within the existing window. Admittedly, the latter option is always a more attractive option to improve the performance of windows for clients; however, the Historic England Guidance states that ‘the use of double glazing will often lead to a loss of significant historic fabric. Adding secondary glazing would often be the preferred option.’.

Other measures you can take to improve your windows thermal efficiency may include draught-proofing. This is one of the cheapest and most effective ways to save energy – and money – in any type of building. Controlled ventilation helps reduce condensation and damp by allowing fresh air in when needed. Draught-proofing either takes the form of compression or wiper seals which are installed around the window frame.

An alternative and perhaps more cosmetically pleasing approach to improving the efficiency of windows though minimising heat loss is to either reinstate or utilise existing historic window shutters should your building have had or still have them. Bringing window shutters back to life will add a secondary layer of protection from draughts in your home and from a heritage perspective, could also be seen as a positive heritage impact, especially if they were originally present but have since been removed. Alternatively, or in addition to window shutters, consider some heavy thermal curtains which will also serve the same purpose.


Walls, attics and floors are the most common locations to install insulation within most buildings. It is usually done by fixing insulation material to the wall, roof or floor, either on internally or externally. Before you go ahead and install insulation, make sure you have been granted the appropriate required consent, such as Listed Building Consent, should it be required.

External Rendering

If your house is currently or was historically rendered, you may have the option to re-render or touch-up areas of damage. External rendering can help you to increase the thermal efficiency of your walls as rendering your property will provide a slight insulating effect. Note that if you are altering the external envelope of your house, you may need planning permission and/or Listed Building Consent.

Heat Source

For optimal prevention, it is a good idea to have at least one heat source that will reach most of the house, i.e., strategically placed radiators or a central fireplace/log burner. Further, you may have the option to install new green energy solutions within your historic building. Having at least one heat source on, even when on sporadically, you will somewhat contribute to keeping the air dry within the house in order to prevent issues such as damp and condensation, both of which have the ability to deteriorate the physical fabric of your building, which in turn may impact upon its overall energy efficiency.


Should you wish you implement any energy preserving strategies within your heritage asset, Blue Willow Heritage can provide expert advice and management strategies to ensure that we can help facilitate the implementation of such measures within historic buildings by successfully guiding clients though to planning permission and listed building consent. If you need help managing your heritage assets, Blue Willow Heritage can help. If you would like to discuss your project or simply need some impartial, no-obligation advice, then please do not hesitate to get in touch.


bottom of page