Improving energy efficiency in a period home without losing its character

Owning a period property is incredibly rewarding. Original sash windows, handmade glass and historic architectural details give older homes a character that simply can't be replicated.

But they also come with challenges. Draughts, cold rooms, rising energy bills and outside noise are common complaints from owners of older and listed properties.

The good news? Improving the energy efficiency of a heritage home doesn't have to mean replacing its original features.

Here's what every homeowner should know.

Can older homes really be energy efficient?

Absolutely.

Older buildings perform differently to modern homes, so they require a different approach. Rather than replacing traditional features, the focus should be on improving the building sympathetically while allowing it to continue functioning as intended.

Small improvements made in the right order can make a significant difference to comfort, running costs and energy efficiency without compromising the character of your home.

Where does most heat escape from an older property?

Many homeowners assume their windows are responsible for all of their heat loss.

In reality, heat can also escape through:

• Roofs and loft spaces
• Floors
• Open chimneys
• Gaps around doors
• Poor insulation

Windows are certainly an important part of the picture, but they work best as part of an overall strategy to improve the building's thermal performance.

Does secondary glazing really work?

Yes.

Bespoke secondary glazing is one of the most effective ways to improve thermal performance while retaining your original windows.

Storm's specialist secondary glazing achieves impressive thermal improvements, with independently tested U-values as low as 1.5 W/m²K, compared with approximately 5.5 W/m²K for traditional single glazing.

Every secondary glazing unit is individually measured and handcrafted to fit your existing windows, helping to:

• Reduce heat loss
• Eliminate draughts
• Lower heating bills
• Improve comfort throughout the home
• Preserve original timber windows and historic character

For homeowners wanting even greater performance, Storm also offers low-emissivity Pilkington K Glass and ORAÉ® low-carbon glass options.

Will secondary glazing reduce outside noise?

It certainly can.

Storm's systems have been independently acoustically tested by Salford University in accordance with BS EN ISO 10140-2:2010 across frequencies from 50Hz to 5,000Hz.

Whether you live beside a busy road, flight path or in a bustling town centre, bespoke secondary glazing can significantly reduce external noise while remaining virtually invisible from inside your property.

Is replacing old windows always the best option?

Not necessarily.

Many original timber windows can continue performing for decades with the right care and maintenance.

Storm now offers professional sash window servicing, helping traditional windows operate smoothly while reducing draughts and improving overall performance. Keeping sash windows in excellent condition is often one of the simplest and most cost-effective ways to make your property warmer before considering larger improvements.

Where additional insulation is required, secondary glazing allows you to retain your original windows while significantly improving comfort and efficiency.

What retrofitting mistakes should you avoid?

One of the biggest mistakes owners make is assuming that older homes should be treated like modern buildings.

Traditional properties were designed to breathe. Using non-breathable materials, such as cement render or inappropriate insulation, can trap moisture within the building and create serious damp problems that are often expensive to rectify.

Another common mistake is blocking ventilation. While reducing draughts is important, older homes still need controlled airflow. Completely sealing chimneys or reducing ventilation without proper planning can increase condensation and encourage mould growth.

Finally, don't prioritise appearance over performance. Cheap replacement windows or unsympathetic modern finishes can damage the heritage character of a property and may even affect its long-term value.

Are there grants available for improving period homes?

Government support for improving the energy efficiency of homes continues to evolve.

Depending on your property, location and circumstances, there may be grants, funding schemes or financial support available for certain energy improvement measures.

Because eligibility changes regularly, homeowners should always check the latest Government guidance before starting work or committing to a project. If your property is listed or located within a conservation area, it's also important to understand any planning or Listed Building Consent requirements before carrying out alterations.

What's the biggest myth about energy efficiency in older homes?

Probably that installing double glazing solves every problem.

While glazing is important, many older homes lose significant amounts of heat through roofs, floors, draughts and poor maintenance.

The best results usually come from taking a holistic approach—maintaining original windows, reducing unnecessary draughts, improving insulation where appropriate and installing sympathetic secondary glazing where additional thermal performance is needed.

Why choose Storm Windows?

For more than 25 years, Storm has specialised in bespoke secondary glazing for listed buildings, period homes and heritage properties across the UK.

Every glazing unit is individually designed to complement your existing windows while providing:

• Exceptional thermal insulation
• Outstanding acoustic performance
• Virtually invisible installation
• Slim, conservation-friendly systems
• High-quality toughened safety glass as standard
• Sustainable glass and aluminium options

Because every heritage property is unique, every Storm solution is too.

Find out more

If you're looking to make your period property warmer, quieter and more energy efficient without compromising its historic character, our team is here to help.

Explore our specialist secondary glazing systems.

See how we've transformed a heritage property.

Or contact Storm Windows today to arrange a friendly, no-obligation survey and discover how bespoke secondary glazing could transform your home.