Why it’s so hard to make eco upgrades to Britain's Victorian homes

The older a property is, the greater the challenge when it comes to improving its energy efficiency, as suggested by figures from the Office of National Statistics (ONS).

Given around one in six homes in England and Wales were built before 1900 – according to figures from the Valuation Office Agency (VOA) – which means thousands of homes are likely to be particularly expensive to heat.

If you’re looking to improve the energy efficiency of your property – and, in turn, reduce your energy bills – you might have the option of an easy fix, or you could potentially be faced with spending thousands. Things like sash windows and cavity walls can mean “simple” changes become a headache.

Here, Telegraph Money explains why Victorian properties can have poor energy efficiency, and offers tips on some cheaper ways to upgrade your EPC rating, even if you have an older home.

How energy-efficient are Victorian properties?

Figures from the ONS report on energy efficiency of housing reveal Victorian properties have an average energy efficiency score of 59 in England and 57 in Wales, which lands them squarely in band D. By comparison, properties built after 2012 score an average of 83 (band B). Band C starts at 69.

Does it mean some Victorian properties can’t be upgraded?

It’s not a fair hypothesis to start with, said Michael Holden, president elect of Propertymark.

“The EPC system right now doesn’t provide a detailed enough picture of the positive contribution older houses provide. With sensible improvements and thoughtful retrofit, we can achieve the best of both worlds – the retention and improvement of our Victorian housing stock, and a reduction of our carbon footprint.”

Energy efficiency can depend on location

Part of a Victorian property’s energy efficiency will depend on the area it’s in, whether it’s terraced housing and the ground and subsoil it has been built on.

Areas vary, says Joanna Cocking, head of prime country sales at Hamptons, an estate agent. “Properties are sometimes not built on robust foundations, and a springy floor means it’s naturally poorly insulated.”

For example, in Fulham, west London, estate agents historically refer to the “Fulham bulge”.

“There were issues with the back walls of Victorian properties in this area – that is, brickwork bulging on the rear extensions. It was easily remedied, but caused because of a lack of foundations. The front bay windows are also prone to subsidence for the same reasons, and again easily remedied. But it was an inherent problem in Fulham,” Ms Cocking explained.

Complicating matters further, some Victorian homes are listed or subject to lease restrictions, which can mean making changes more difficult. This is the case for Gareth Bowden of Winkworth estate agents.  

“Victorian homes in my areas of Mudeford and Highcliffe in Dorset are usually listed. In these cases, insulating the windows from the inside and adding secondary glazing becomes necessary, but it compromises the original window’s integrity and aesthetics,” he said.

Common window upgrade issues

Victorian properties often feature single-glazed sash windows, which, according to Ms Cocking “just haemorrhage heat”.

The cost of replacing them with double-glazed sash windows can be quite expensive, ranging from £1,000 to £5,000 per window, depending on the size. As Victorian-style properties tend to have large windows, the costs tend to be closer to the higher end.

Sensitive secondary glazing can be applied on the inside of a house, but it can be difficult as it will sometimes need to be custom-made to individual windows. If you have features like stained glass panels – which are most commonly found in Victorian properties – secondary glazing can be even harder to fit, especially if the stained glass flanks front doors.

“There are some amazing windowmakers helping with restoration work,” said Ms Cocking. She cites old Crittall windows (notable for featuring large glass panels with black metal frames) being replaced by replica sealed units as a successful example. “You think it’s the original, but it’s very clever double or triple glazing.” 

Cavity walls could block efficiency measure

Cavity walls also pose a significant challenge. Retrospective cavity wall insulation – if indeed the property has a cavity, as many Victorian houses were built without cavity walls – can cause damp issues further down the line if the cavity is breached.

If your home is on the top or middle floors of a Victorian house, insulating these walls can also be difficult, and very expensive.

“Some owners have resorted to insulating from the inside, which often requires erecting expensive scaffolding,” said Rupal Patel, director of Winkworth’s office in Shepherds Bush.

He admits significant financial investment is required here.

“We’re talking from a few hundred pounds to £3,000-£4,000 depending on the size of the property and whether the cavity can be filled externally (which is cheaper), or an internal insulation needs to be added. With plastering and redecoration costs, this can then push the bill up over £10,000 in some instances.”

Mr Patel is optimistic about Victorian properties’ potential to achieve high energy efficiency ratings, but realistic about costs involved.

“It’s challenging but not impossible. It’s about careful planning and adopting innovative solutions, but will likely demand a significant spend and compromises on certain architectural features,” he said.

Mr Bowden added: “The properties which have been refurbished tend to have been stripped right back to the original brick work, had internal insulation fitted and then replastered – this means that modern plumbing and wiring can also be fitted and, in some instances, underfloor heating added.”

This article was first published on June 11 2023 and has since been republished.