BUILD FOCUS:

ROAD TO NET ZERO: RETROFITTING THE UK’S COMMERCIAL AND RESIDENTIAL PROPERTIES

Both commercial and residential buildings in the UK face significant challenges when it comes to addressing the net-zero agenda. Data from 2020 demonstrated that buildings and construction work in the UK produced nearly 1.9 million metric tons of CO 2 emissions 1

For existing commercial buildings, challenges include greenhouse gas emissions, energy waste and environmental degradation, whilst residential properties face challenges around energy consumption, carbon emissions and inadequate insulation. Retrofitting buildings can offer a viable pathway to address some of these issues and accelerate progress towards achieving net-zero targets set by the UK Government. Retrofitting energy-efficient technologies into existing buildings can enhance their sustainability performance and help to reduce their environmental footprint.

Commercial buildings

C ommercial buildings in the UK account for a significant portion of energy consumption and carbon emissions. These structures face challenges such as high energy consumption and significantly larger carbon footprints than residential buildings. Retrofitting offers a way to tackle these problems. Implementing energy-efficient measures, such as upgrading heating and cooling systems, improving insulation, upgrading lighting systems, optimising

HVAC systems and automating energy management systems, can significantly reduce energy consumption and lower carbon emissions. Furthermore, enhancing insulation and improving building envelopes can minimise heat loss and gain, reducing the demand for heating and cooling. Commercial buildings in the UK will be required to have an energy performance certificate (EPC) by 2025, with the Government proposing to introduce a requirement to have an EPC rating of at least ‘B’ by 2030 2 Assent worked on Stok, the repurposing of an old retail outlet in the centre of Stockport, Cheshire, into a flexible workspace. The building, developed by Glenbook, has achieved an EPC rating of A, thanks to attention being paid to the design of the redevelopment at every stage of the process. This is one example of the increased focus on positive environmental action that developers are taking to futureproof structures.

B y incorporating renewable energy technologies, like photovoltaic panels, commercial buildings can generate clean energy on site, further reducing reliance on fossil fuels. Retrofitting commercial buildings not only reduces operational costs but also helps achieve the UK’s net-zero emissions targets. According to a report and analysis published by the UK Green Building Council, energy consumption across commercial buildings in the UK must be reduced by 59% by 2050 3 to align with the Paris Agreement. Whilst sustainability is now becoming an essential part of the built environment sectors, being at the forefront of these changes will add attractiveness to commercial buyers and leaseholders.

Residential properties

A ccording to reports, the average home in the UK is responsible for producing 8.1 tons of CO 2 annually 4 . Furthermore, research states that all UK homes will need to be retrofitted to an EPC band C standard by 2025 5 to meet the UK Government climate targets. Retrofitting residential properties offers an opportunity to address these issues and improve energy performance. Upgrading insulation, installing energyefficient appliances and integrating smart home technologies are effective ways to enhance energy efficiency in residential buildings. Improved insulation reduces heat loss, leading to lower energy consumption for heating and cooling. Assent Building Control worked on a project alongside EcoArc Architects, providing building control services on a bespoke renovation, turning an old windmill into a highly-efficient family dwelling. The project required insulation of the existing building structure to support sustainability requirements, which were achieved by working closely with the architect.

S mart home automation enables better energy management, allowing residents to optimise their energy usage. Moreover, integrating renewable energy technologies, like photovoltaic panels, enables homeowners to generate clean energy and reduce reliance on conventional energy sources. Retrofitting residential properties with technologies, such as this improves the EPC rating, lowers carbon emissions and promotes energy savings, ultimately contributing to the UK’s net-zero objectives and improving running costs and saleability of the home.

Retrofitting as a solution

R etrofitting is crucial in achieving net zero. With a significant portion of existing buildings constructed before modern energy-efficiency standards, retrofitting provides an opportunity to improve energy performance and reduce carbon emissions. Whilst retrofitting may not currently be the most affordable option, the long-term cost savings on energy bills and futureproofing homes is undoubted. As a principle, retrofitting maximises the utilisation of existing infrastructure whilst minimising the environmental impact associated with the production of new materials. Additionally, retrofitting enhances occupant comfort and wellbeing and contributes to a sustainable and resilient economy.

R etrofitting aligns with the principles of a circular economy, as it extends the lifecycle of buildings and reduces construction waste. Did you know that the embodied carbon that comes from the construction of a typical new-build property is equivalent to up to 20 years of operational carbon emissions 6 ? Therefore, retrofitting, on the whole, offers a far more sustainable solution to reaching net-zero targets. By prioritising retrofitting with targeted Government support, the UK can transform its built environment, mitigate climate change and move closer to a sustainable, net-zero future.

The Building Safety Act and retrofitting

T he upcoming changes being brought about by the Building Safety Act in the UK will have a significant impact on retrofitting mixed-use commercial and residential properties. It introduces stricter safety standards and regulations, not only for high-risk buildings (over 18m/seven storeys and more than two dwellings), but all buildings in the UK, including residential, requiring retrofitting projects to comply with enhanced safety measures.

T he Building Safety Act ensures that retrofitting projects prioritise both safety and sustainability in the same way that new developments have to, leading to the creation of safe and environmentally-friendly buildings in the UK. It also emphasises the competency and accountability of those involved in retrofitting projects. Additionally, the act introduces third-party oversight and a gateway process for higherrisk buildings, ensuring compliance with Building Regulations. Architects, developers and contractors must all be aware that the plans submitted for approval should be full and final and cannot be adapted on site. Therefore, early partnership with building control is essential to ensure all regulations are met and safety standards adhered to.

Conclusion

S ustainability is at the forefront of the construction industry’s agenda, particularly in the UK, where efforts to achieve net-zero targets are being prioritised. The Construction Leadership Council has recently launched the Zero Diesel Sites Route Map, backed by Nasrat Ghani, the Minister for Industry and Economic Security, which is designed to be a key step in making UK construction the greenest in Europe. Retrofitting commercial buildings and residential properties offers an effective solution to address sustainability challenges and drive progress towards a net-zero future for all structures. As the industry embraces retrofitting practices, it propels the UK towards a more sustainable future, leading the way to a net-zero built environment.

www.assentbc.co.uk

FOOTNOTES:

1https://www.statista.com/statistics/486047/co2emission-from-buildings-and-building-constructionworks-uk/#:~:text=CO2%20emissions%20 from%20buildings%20and,in%20the%20UK%20 1990-2020&text=Buildings%20and%20building%20 construction%20works%20in%20the%20United%20 Kingdom*%20produced,compared%20to%20the%20 previous%20year.

2https://conceptenergy.org/ukgbc-launchesguide-to-low-carbon-retrofits-for-commercialbuildings/

3https://workplaceinsight.net/retrofit-is-essentialfor-the-uks-stock-of-poor-performing-commercialproperty/

4https://heatable.co.uk/boiler-advice/averagecarbon-footprint#:~:text=In%20short%2C%20the%20 report%20makes,current%20average%20of%20 8.1%20tonnes.

5https://www.trustmark.org.uk/homeowners/ whole-house-retrofit#:~:text=Why%20is%20 Retrofitting%20Your%20Home,band%20C%20 standard%20by%202035.

6https://www.netzerocarbonguide.co.uk/guide/ early-decisions/retrofit-or-new-build/summary

HOW TO DESIGN AND BUILD FIRE-SAFE TIMBER BUILDINGS

Nick Boulton, Chief Executive Officer of the Trussed Rafter Association and Chief Technical Officer of Timber Development UK, outlines how to design and build timber buildings to ensure they are safe from fire.

If we are to meet our net-zero targets, the built environment must reduce its carbon footprint. This means reducing the operational carbon from a building’s heating and lighting, as well as the embodied carbon emitted from construction processes and materials.

O ne of the best ways to reduce embodied carbon is through the use of more sustainable materials, and responsibly-grown timber is one of the most sustainable materials available to us now.

However, designing and building a timber building that is safe from fire requires specific expertise and knowledge. It is essential to understand the unique characteristics of timber and to ensure that building codes and safety standards are adhered to.

Reaction vs resistance to fire

To understand a building material’s ability to withstand fire, there are two main factors to consider: reaction to fire and resistance to fire. It’s crucial to differentiate between the two.

Reaction to fire

Reaction to fire refers to whether a material acts as fuel for the fire prior to a flashover. Materials are categorised using a fire classification system consisting of seven groups, from A to F, where A indicates non-combustible materials and F indicates highly flammable ones.

D uring the early stages, when a fire is still becoming established, there are five important factors to evaluate and measure as follows:

Ignitability: How readily will a material ignite and catch fire?

Spread of flame: Once ignited, how quickly will flames spread across the surface of that material?

Heat release: Once alight, how much heat energy will be generated by the burning material?

Smoke production: How much smoke will be generated by the burning material?

Flaming droplets: Will the burning material disintegrate and produce burning droplets or debris that may fall onto and ignite other surfaces?

Timber has predictable performance in a fire

I n a fire, timber will burn steadily at a predictable rate and has low heat conduction. The timber chars at a low rate and in a uniform way; the charcoal that is formed on the surface of the timber serves to insulate and protect the core.

C harring should be taken into account when using timber for structural purposes. The thickness of a loadbearing timber can be chosen based on its strength after charring to maintain structural integrity in a fire.

If timber is protected from direct attack by a fire source, such as in timber-frame buildings with plasterboard linings, it cannot ignite and burn until the surface temperature reaches at least 400°C.

Where necessary, timber’s reaction to fire can be improved through the use of a Wood Protection Association (WPA) Benchmarkapproved flame-retardant treatment and quality-assured application system.

Resistance to fire

O nce a flashover occurs, the fire becomes uncontrollable and all combustible materials are assumed to be burning.

At this point, the focus shifts to ensuring fire containment for safety purposes. This is achieved through the performance of building structures and design elements, such as walls, ceilings, floors and doors, and is not solely based on the performance of individual materials.

T here are two different types of fire resistance measures for timber buildings: passive fire protection and active fire protection.

Passive fire protection

Passive fire protection measures are designed to contain or slow down the spread of fire and smoke through the building structure. They include fireresistant walls, floors and ceilings, as well as fire doors, fire dampers and fire-resistant glazing. Passive measures are intended to prevent the spread of fire and smoke, limit damage to the building and provide time for occupants to evacuate safely.

T he necessary measures will differ according to building type and use and are outlined in Approved Document B. For example, when timber-trussed rafters are used for a roof in a residential home, the plasterboard that forms the ceiling below must have 30-minute fire resistance.

I n addition, fire-retardant treatment is often applied to raw and finished wood to meet the fire resistance standards outlined in BS 476-22:1987.

C avity barriers also play a significant role in passive fire protection. Timber frames within a construction must be placed within a ventilated cavity to avoid rotting. However, without cavity barriers, there is a risk of fire entering this cavity and causing the building to burn from inside the walls.

To prevent this, cavity barriers made of mineral wool insulation are used in timberframe buildings. This prevents the spread of hot gases from a fire and limits its ability to spread. It is essential that these barriers are properly installed on site for them to work correctly.

Active fire protection

A ctive fire protection measures are designed to detect and control a fire when it occurs. These include fire alarms, sprinkler systems and other fire suppression systems. These measures are intended to extinguish the fire quickly or contain it until firefighters arrive, reducing the damage to the building and protecting occupants.

Together, passive and active fire protection measures contribute to the overall fire resistance of a building, helping to ensure the safety of occupants and limit the potential damage caused by a fire.

Risk assessments

A fire risk assessment can identify potential fire hazards and evaluate the likelihood and consequences of a fire, enabling appropriate measures to be taken to prevent or minimise the risk of fire. S uch assessments can also help identify appropriate fire protection measures, such as the installation of sprinkler systems or fire-resistant materials, to enhance the safety of occupants and protect property. Ultimately, conducting a fire risk assessment for timber buildings is an essential step in ensuring the safety and wellbeing of occupants and the longevity of the structure.

Timber Fire Safety website

The timber industry recently launched a new information resource known as Timber Fire Safety. This peer-reviewed website gives a single point of access to information and guidance regarding fire safety in timber buildings with a focus on both UK regulations and European standards.

www.timberfiresafety.org

Access 360 Celebrates Cpd Success

ACCESS 360 www.access-360.co.uk cpd@access-360.co.uk

Access 360 delivered over 150 Continuing Professional Development (CPD) seminars throughout 2022, sharing expert knowledge and advice with over 3000 architects, specifiers and contractors. Access 360’s complete suite of RIBAaccredited CPDs provides industry professionals with the latest guidance on regulations and best practice. This includes its most popular CPD, Fire & Smoke Access Solutions, which explores the fundamentals of fire ratings and certification, in addition to successfully managing access, fire safety and security requirements for commercial and residential buildings. The Roof Access and Natural Smoke Ventilation for Flat Roofs CPD outlines current practice regarding the provision of smoke ventilation and roof access whilst discussing new design considerations and applications as a result of latest Building Regulations. Access 360’s flagship CPD, Safe, Practical and Aesthetic Roof, Ceiling, Wall and Floor Access Solutions, provides an essential guide to the specification of access solutions.

Knauf Insulation Launches Omnifit Slab 32

KNAUF INSULATION www.knaufinsulation.co.uk/omnifit-slab-32 01744 766600 info.uk@knaufinsulation.com

Knauf Insulation has launched OmniFit Slab 32, the first 32-lambda glass mineral wool insulation slab on the market for use in light steel frame systems (SFS) as part of a rainscreen facade or other external wall build ups. “From thermal performance to fire safety, the regulations governing how buildings are built and perform are getting stricter,” explains Liliya Luke, Glass Mineral Wool Product Manager at Knauf Insulation. “We have launched OmniFit Slab 32 to help our customers deliver the low U-values required without compromising on fire safety, acoustic performance or sustainability. Specifiers can now optimise their rainscreen facade systems by adding the benefits of glass mineral wool to their build up – delivering acoustic performance and reduced embodied carbon compared to rock-only solutions, with an insulation specification that remains completely non-combustible.” OmniFit Slab 32 is primarily designed for use with Rocksilk RainScreen Slab when used in rainscreen applications and is suitable for use in the external wall systems of all residential buildings over 11m tall and relevant residential buildings over 18m tall.

ROCKWOOL INSULATES NEW HOMES IN ADAMSTOWN, CO. DUBLIN

ROCKWOOL

Rockwool Launches New Soundpro Guide

ROCKWOOL www.rockwool.com/uk/soundpro

To support specifiers in selecting acoustic solutions for education and residential applications, ROCKWOOL has launched ROCKWOOL SoundPro. The specialist guide combines technical data, product information and the latest regulatory advice in one place, aiding the specification of stone-wool solutions for settings where sound insulation is key. ROCKWOOL SoundPro outlines the importance and principles of good acoustic design and how to effectively enhance the acoustic capabilities of building projects. ROCKWOOL SoundPro includes various strategies and functions that can reduce the amount of unwanted noise transfer through walls, floors or roofs.

01656 868490 technical.solutions@rockwool.co.uk

Hallwell by Hugh McGreevy & Sons is a development of 100 new homes designed by Hugh McGreevy’s in-house team. They were planned with a masonry cavity wall construction and a preference for stone-wool insulation due to its non-combustible properties. Working with the developer, ROCKWOOL conducted all U-value calculations for the project. These demonstrated that NyRock Cavity Slab 032 would achieve the target U-value of 0.18 W/m 2 K within the 200mm cavity space. This led to the specification of 14,000m 2 of 160mm NyRock Cavity Slab 032 in a partial fill application. To satisfy fire regulations in cavity applications, 9000m of ROCKWOOL TCB Cavity Barrier was also specified.

01656 868490

Sto Insulation Raises The Temperature For Global Headquarters Building

STO www.rockwool.com/uk technical.solutions@rockwool.co.uk www.sto.co.uk

A StoTherm Mineral external wall insulation system from Sto was chosen to deliver excellent thermal performance for an office building in Loughborough. The Sto system was installed on the £21m building on Loughborough University Science & Enterprise Park (LUSEP), which now accommodates the flagship office of The Access Group. The StoTherm Mineral system uses mineral fibre boards to provide reliable thermal insulation. Its compact single-leaf construction allows this to be achieved without reducing the building’s interior space. It can be installed without the need for additional expansion joints to create smooth and visually-appealing external surfaces, and it also delivers both unrivalled fire protection and improved sound insulation.

0141 892 8000 info.uk@sto.com