Preserving the past

The United Kingdom is home to some amazing structures, both ancient and historic. They’re recognised the world over.

They create opportunities for the built environment to create places that matter and tell stories about who we are as citizens. When it comes to preserving these buildings for future generations, a tailored approach is needed. Mace has experienced this first hand as both a builder of landmark architecture as well as an expert in retrofitting historic buildings to be fit for the future.

Despite any approach being tailored to the asset in question, there are core building conservation principles which we believe must be followed to achieve the best results. The responsibility falls on site owners and built environment professionals to address these principles as part of delivering a robust, effective and timely programme to bring any heritage building up to modern standards.

Ensuring strong bones

As much as we cherish the history of our buildings, it is critical they remain fit for purpose. Ensuring that all electrical, plumbing and heating is in place and compliant with current regulations is an essential task, helping mitigate the risk of fire, flood or operational failure. In addition, a building must be safe for continued use in line with new legislation, like the Building Safety Act, as well as compliant with ecological rulings, including hitting biodiversity net gain mandates. Keeping up with accessibility requirements is also essential to meet the needs of its users for years to come.

Historic buildings also need to be made resilient to our changing climate. With increased rainfall resulting in a higher chance of flash flooding, older structures need to be assessed for drainage as well as how well their foundations can cope with the ground drying or heaving.

However, we know that each building is unique and brings its own challenges. They are incredibly varied, ranging from intricate layouts with grand rooms and high ceilings to landmark structures that define a local area. Each endeavour to bring a heritage building up to modern standards must be tailored to the targeted needs of the site in question, as well as its intended users.

This approach begins at the start of the project and defines future activity. Detailed condition surveys can uncover the quality of all existing cabling, plumbing, and structures, and identify hazardous substances, as well as opportunities to improve building safety and accessibility. Doing so informs the business case as well as the necessary pace for the change programme.

Defining the approach that works best for the future of the asset eliminates significant risks during the project, and significantly extends the life of the building.

Retrofit for the future

While these activities can result in a building that is more efficient, this isn’t enough to meet the urgent need to decarbonise global building stock. With the built environment responsible for around, 40% of all carbon emissions, increasing energy efficiency must be a top priority as highlighted by the recent Science Based Targets initiative (SBTi) framework.

Any plan to reduce carbon emissions should come down to two factors: reduction of existing energy demand and careful selection of energy sources.

For the former, we need to look closely at a building’s performance and the condition of the existing fabric to identify efficiency gains. This could include ‘light’ retrofit options to improve existing components, including lighting or control upgrades and pump motor replacements, or ‘deep’ retrofit options resulting in significant improvements of the building’s fabric. These include window upgrades or additional wall insulation, as well as major upgrades of building services through exploring space heating or cooling and ventilation system upgrades.

For the latter, we need to analyse decarbonisation options considering existing infrastructure, opportunities for utilities upgrades and changeover. For instance, we could reduce a reliance on fossil fuels through installation of ground or air source heat pumps, or connecting to a decarbonised district heat network, with the goal of achieving complete independence from carbon-based fuel sources through long term planning. Other considerations include installation of solar panels, with or without battery storage, and other renewable technologies. 

It is critical to build teams with the right skills and experience to provide an informed route forward and guide a strong approach to decarbonising a heritage site.

Programme around discovery to minimise delays

No retrofit project comes without snags or surprises. In heritage assets, this is even more pertinent, since there can be greater risk of poor building records or outdated construction methods. In some cases, we’ve found unrecorded rooms and passages when working in historic buildings, as well as examples of poor workmanship, missing fire compartmentation and structural damage.

Discovery must be incorporated into any project strategy, programme and cost plan, with an appropriate level of contingency and risk allowance at the outset, directly reflecting the knowledge of the building, with a robust approach to change management from the start.

How the risk of discovery is managed through the procurement and contracting strategy, with appropriate ownership aligned to each stage of the project, is key to success. All designs must be qualified and checked simultaneously with the enabling works taking place, reacting to fresh discoveries and tweaking to best meet the challenges that arise.

The process of preserving any heritage building can be a roller coaster of challenges, obstacles and unwelcome surprises. However, if we are to ensure that such sites are fit for a modern age, meeting the expectations of today’s users while living up to current safety and sustainability standards, it is a challenge worth rising to.