Retrofit for Tenements

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The Georgian and Victorian tenements of Edinburgh, Glasgow and other Scottish cities are among those cities’ most notable architectural features. They add an undoubted grandeur and character to the skyline and form the backdrop to numerous tourist selfies. 

However, as every tenement tenant or flat owner knows, they’re not the most energy efficient or sustainable homes. They provide a range of challenges to those keen to decarbonize or reduce their energy bills. 

Tenement retrofitting is a movement and a set of technologies aiming to make such domestic spaces more sustainable and fit for 21st century living. It’s not just a trend popular with landlords and homeowners, however; it’s also a significant priority of the Scottish Government. 

The Scottish Government published its Heat in Buildings Strategy in October 2021. In that document, the government laid out its medium-term aims to improve the energy efficiency of all buildings. These aims included: 

    The intention to introduce legislation to require all buildings to meet energy efficiency standards by 2033 (equivalent to the Energy Performance Certificate [EPC] Band C). 

    Private rented properties would have to achieve this standard by 2028. 

    All homes to have zero emission heating systems in place by 2045. 

These policies were informed by the results of the Scottish House Condition Survey, which found that over 1.6 million homes achieved an EPC rating of Band D or lower, and more than 2 million homes using mains gas or oil as their main heating fuel. 

Recommendations made in 2023 by the Tenements Short Life Working Party included: 

    The provision of government funding for homeowners to help meet these targets. 

    A phased approach to tenement regulation, recognizing the special challenges of such homes. 

    Whole Buildings Assessments for energy efficiency and emissions analysis. 

    Changes to The Tenements Act to reinforce the requirement for insulation. 

In short, the needs of homeowners and landlords align well with the government’s own aims, even as they introduce some major challenges to overcome. Time will tell whether these priorities remain in place following the 2024 general elections. There are currently no signs that these objectives won’t carry forward in the new political environment. 

Tenement retrofitting is the addition of modern, innovative solutions to regulate the environments of these homes.  

The term is wide-ranging enough to encompass sensors to identify needs and risks, and remote-control mechanisms to regulate temperature, lighting, air conditioning, humidity, air quality and other variables. 

Every tenement has its own unique challenges. No single solution is fit for all such properties. This creates a direct role for forward-thinking factoring businesses and savvy homeowners to devise bespoke systems optimised for their unique environments. 

Retrofitting can include these interventions: 

•     Damp sensors to provide early warnings, protect inhabitants’ health, and save money. 
•     Automated boiler or radiator systems to offer more sophisticated control of water heating and distribution. 
•     In-window air conditioning systems, with automation and remote control. 
•     Solar panels and electricity distribution systems. 
•     Platforms and apps to provide remote control over home systems. 
•     Insulating wallpaper and interior paints 
•     Window insulating film and weatherstrips for single glazing. 

Technically, even the fur-fabric draught excluder you made in home economics class is an example of retrofitting. It’s an add-on that addresses an engineering problem. 

What challenges do tenements present to retrofitters? 

With all these potential interventions, becoming more sustainable, and saving money on energy bills might seem a no brainer. But there are difficulties to overcome in tenement buildings. 

Major challenges to retrofitting include: 

    Historically poor insulation: solid stone walls lack cavities in which insulation might be installed. 

    Stone walls can be hard to heat and can be particularly cold in winter. 

    Old buildings are prone to rising damp and other forms of moisture ingress. 

    Many listed buildings have traditional sash windows which can be drafty. 

    Similarly, single glazing is common, which is less efficient in heat retention. 

    Historical plumbing may contain lead pipes, leaks or old fittings which are less well-insulated than modern systems. 

    The high ceilings common to Georgian tenements provide space for rising warm air and create a larger interior room volume, making them harder to keep warm. 

    Listed buildings may have restrictions on permitted alterations, particularly on exteriors.  

    Roofs may not be accessible or suitable for the installation of solar panels. 

However, even with these challenges, innovative start-ups have created smart devices and systems that create more efficient homes and improve communal spaces. 

Let’s turn finally to some good news, in the form of two outstanding examples of tenement retrofitting that works. 

1: Niddrie Road, Glasgow 

In 2021-22, a joint project of CCG Construction, John Gilbert Architects, and Southside Housing, retrofitted a tenement of eight flats with the intention of achieving at least a 70% reduction in energy consumption.  

To this end, the project installed loft insulation, internal and internal wall insulation, triple-glazed doors and windows, mechanical ventilation with a heat recovery system, and wastewater plumbing with its own heat recovery aspect. 

With all these modifications in place, the project achieved energy recovery savings of over 90% and won a Scottish Design Award nomination. 

2: Historic Scotland Pilot, Edinburgh 

An innovative pilot programme run jointly by Historic Scotland, Napier University’s Scottish Energy Centre, and Castle Rock Edinvar Housing Association took five pre-1919 Category B listed tenements and retrofitted them with energy saving features while maintaining their architectural integrity. 

The changes made to the five tenements included rigid and cavity insulation, concealed secondary glazing, and the use of thermal transmittance sensors to record heat loss.  

The results were dramatic, with an average 71% reduction of wall and window heat loss in the single glazed properties and 88% for double glazed windows. 

The second case study discussed above, from 2016, demonstrates that retrofitting even the most challenging tenements is possible, where there’s a will and a commitment to innovation. 

There are other challenges we’ve not discussed here; landlord, owner, and tenant buy-in being a chief roadblock. Retrofitting can be disruptive, in the short term, even though it delivers long-term gains. 

However, given the impetus from the Scottish government and local councils to make all buildings more sustainable in the coming decades, retrofitting is very much here to stay.  

The good news is that those energy efficiency investments that will pay off for decades to come for both homeowners and tenants.