Episode 82:

Hello and Welcome to the Part3 with me podcast. 

The show that helps part 3 students jump start into their careers as qualified architects and also to provide refresher episodes for practicing architects. I am your host Maria Skoutari and this week we will talking about The Future Buildings Standard. Todays episode meets PC1&3 of the Part 3 Criteria.

So back in episode 72 I spoke about the Future Homes Standard which applies to domestic buildings ensuring they are built future proofed to reduce energy usage and greenhouse emission of new buildings from 2025.

Today we will be covering the Future Buildings Standard, so what is the Future Buildings Standard:

In 2020, the UK government introduced a policy called the Future Buildings Standard which sets out the changes to Approved Documents L and F of the Building Regulations which came into force the past year and focuses on new non-domestic buildings but also includes policy relating to existing non-domestic buildings. The full Future Buildings standard will be implemented in 2025. 

The aim of the Future Buildings Standard is:

• For new non-domestic buildings to produce 27% less CO2 emissions in comparison to current buildings as currently, heating and powering buildings accounts for 40% of the UK’s total energy usage.  
• Buildings built to the Future Buildings Standard will be zero carbon ready, with the ability to decarbonise over time 
• Low carbon heat sources for heating and hot water will be integral to the specification of the Future Buildings Standard 

What does a Future Buildings Standard building look like:

Non-domestic buildings are more diverse in type, size, complexity and function and the Future Buildings Standard, therefore, needs to reflect this diversity. All heat and hot water need will need to be met through low-carbon sources to meet the Future Buildings Standard primary energy targets. A large proportion of this low-carbon heat will come from the national grid, which is continuously moving towards net zero meaning new buildings constructed to the standard will be zero carbon ready. 

Whatever the non-domestic building type, the best fabric standards should also be considered to keep an optimal balance between heating, cooling and daylight provision. The low carbon heating technologies which support the level and scale of change sought from the Future Buildings Standard include:

• Heat Pumps, which deliver heat much more efficiently as they capture renewable heat from the atmosphere and help keep running costs and electricity demand down. For high water demand in buildings such as hotels or hospitals, another solution may be needed as heat pumps may not be suitable for higher hot water temperatures
• Another source to be considered are heat networks which are a distribution system taking heat from a centralised source and then disperses it to a number of different buildings. This approach can decarbonise more easily because new technologies can be added to the system with minimal disruption to the individual buildings
• Another is direct electric heating, such systems however, will put too high a demand for electricity and may as a result impact the national grid and it is also very expensive to run
• Some other technologies can also include hydrogen in the future

Now when it comes to actually implementing the Future Buildings Standard:

It will be implemented through the Building Regulations, and the government suggests splitting the different types of non-domestic buildings in relation to their water heating demand as:

• Type 1 Demand, which is space heating demand more suitable for heat pumps and domestic hot water demand more suitable for point of use or heat pump - type 1 has been identified for buildings such as office, multi-residential buildings, prisons, schools, retail units, community centres, courts, libraries, museums, airports, data centres and theatres
• Type 2 Demand, which is space heating demand more suitable for heat pumps and have high domestic hot water demand, which may be less suitable to be provided using point of use or heat pumps - type 2 has been identified for buildings such as hotels, hospitals, health care, restaurants
• Type 3 Demand, which is space heating demand less suitable for heat pumps and domestic hot water demand more suitable for point of use of heat pump - type 3 demand has been identified for buildings such as warehouses, industrial buildings and sports halls. 

Buildings with Type 1 and Type 2 levels of demand should be ready to adopt heat pumps or other forms of low-carbon space heating in 2025. There may be more challenges for buildings with Type 3 demand, for example because they are made up of large spaces which are more suited to radiant or spot-heating for which heat pumps are not the most appropriate technology. Also buildings with Type 1 and Type 3 demand should be ready to adopt either electric point-of-use domestic hot water heating or heat pump domestic hot water heating in 2025. Buildings with Type 2 demand are likely to require high volume low-carbon domestic hot water production, which could include some types of heat pumps. While some suitable heat pump domestic hot water systems already exist, a longer lead-in time may be required so that these systems can become more established before adopting these system types as part of the minimum standard for buildings with Type 2 demand. 

Although it has been recognised that this approach is too oversimplified and needs to be more flexible and account for other factors as well since usage and performance can vary between buildings in the same category and the heat demand shouldn’t be dictated by the buildings typology alone.

Now, to support the implementation of the Future Buildings Standard it is proposed that its supported by two workstreams of targeted research and engagement with the industry: 

• The first workstream would implement the full adoption of the Future Buildings Standard for buildings which are more suitable for low carbon heating and/or hot water. This will include low carbon space heating for buildings with Type 1 and Type 2 space heating demand and low carbon hot water heating for buildings with Type 1 and Type 3 water heating demand. 

• The second workstream would provide specific support to the full adoption of the Future Buildings Standard for more challenging demand types. This will include low carbon space heating for buildings with Type 3 space heating demand and low carbon hot water heating for buildings with Type 2 hot water demand. 

To support this transitioning, the government is working with the relevant sectors and suppliers to up-skill workers and provide them with the necessary training and skills needed for construction including reselling and upskilling and filling the skills gaps the sector needs to build greener. 

Now when it comes to measuring the energy performance of the buildings, through the uplifts proposed under Approved Document Part L, the government proposes they are measured against:

• Primary energy as the principal metric which is energy from renewable and non-renewable sources
• CO2 emission as the secondary metric 
• Airtightness testing methodology
• And Uplifting the minimum standards for thermal elements and controlled fittings

To determine the energy performance of a non-domestic building, calculations must be carried out according to the methodology approved by the Secretary of State which is the National Calculation Methodology (NCM). Two routes are available for assessing buildings, both of which must be compliant with the NCM: 

i) For simple buildings, using the Simplified Building Energy Model (SBEM) 

ii) For more complex buildings, using an approved Dynamic Simulation Method 

The non-domestic sector is generally much more diverse than the domestic sector, and the performance issues involve a wider range of technical challenges. The Government proposes these can be addressed through: 

• Revising the outputs from the Simplified Building Energy Model to enable easier checking by building control on building completion 
• Encouraging designers to undertake better design detailing in thermal bridging 
• Developing the Simplified Building Energy Model and the national calculation methodology to better account for energy uses and to incentivise appropriate design solutions, which include: 
• Providing more accurate ventilation calculation assumptions. 
• Improved lighting calculation to better reflect actual use. 
• Reviewing the activity database to better reflect actual building use 
• Revising the way that hot water demand is calculated to better match real-life demand. 

Then it is also recommended to introduce more challenging energy efficiency standards and improving compliance by: 

• Requiring developers of large buildings to carry out energy- forecasting at design-stage, to provide appropriate benchmarks for in-use energy performance
• Updated minimum standards to improve the efficiency of services and fabric specification and reference to the latest standards. 
• Making the legal requirement for adequate commissioning clearer
• Enhancing the regulations and guidance for assessing the energy performance of building services systems during commissioning. 
• Introducing guidance for appropriate sizing of systems and avoiding over/under-sizing. 
• Improving the guidance for more accurately calculating insulation performance (U-values) and referring to the latest industry standard. 

And also supporting building owners to better understand how to use their building efficiently, by improving standards for energy metering to allow the occupiers to better understand the energy they are using in their buildings. 

These proposals focus on ensuring that buildings are well-designed and well-commissioned and capable, under standard operating conditions, of meeting the carbon targets set by the new standards. It is anticipated that the standards will encourage developers to install low-carbon heating in new developments. For example, installing a heat pump for heating in an air-conditioned office could be a lower capital cost solution than installing gas boilers and photovoltaic panels. Adopting this approach allows the low-carbon heating sector to grow at a sustainable pace before becoming part of the minimum standard proposed to be introduced in 2025. 

Now looking more specifically at the minimum standards for thermal elements in new non-domestic buildings, is is proposed that minimum levels of fabric performance should be set out in the standard and can also be found in the updated Approved Document L. Building Regulations set out the energy efficiency standards for new and replacement thermal elements in existing non-domestic buildings and these standards apply:

• when providing a new element in an existing building; 
• when providing a new element as part of an extension of an existing building; 
• when replacing a controlled fitting (e.g. windows and doors); or  
• when completely removing and replacing a thermal element (i.e. walls, floors, roofs). 

The Future Buildings Standard, therefore, recommends these requirements and standards set within the Building Regulations are retained and continue to include minimum levels of fabric performance, as they have been within the latest update of the Building Regulations. Updates to U-Values for roof lights are also to be incorporated in the Future Buildings Standard as per the Future Homes Standard. 

Now when it comes to air distribution, it has been recommended and updated within the Buildings Regulations that the minimum standards for air distribution units:

• For all supply and extract systems to have heat recovery where technically feasible 
• Maximum specific fan power for zonal supply and extract ventilation units, such as ceiling void or roof units serving single room or zone with heating and heat recovery is set at 2.3W/(l.s)
• Other systems have had a value of 0.4W/(l.s) incorporated into the maximum specific fan power as an allowance for heat recovery. 
• Fan assisted terminal variable air volume unit maximum specific fan power reduced to 0.5W/(l.s); 
• Fan coil unit maximum specific fan power to be reduced to 0.3W/(l.s). 
• And for air distribution systems using active chilled beams, an additional allowance of 0.3 W/(l.s) is provided. 

Heating and cooling systems are also proposed to be fitted with self-regulation devices which can be achieved by including devices for separate regulation of temperature in each room or designated heating zone, this can be a thermostatic radiator valve for example. 

Now in terms of lighting, the minimum efficacy proposed in new non-domestic buildings should be:

• 95 luminaire lumens per circuit watt for general lighting; and 
• 80 luminaire lumens per circuit watt for display lighting. 

With LED lighting being the most common installed in non-domestic buildings due to their efficiency and longevity.  

Another key system for non-domestic buildings is the Building Automation and Control System used to monitor and control a buildings environment and services, such as heating, ventilation, air conditioning and so on. Under the standard, these systems are proposed to become a regular fixture within non-domestic buildings that have a heating or air conditioning system as they are both cost effective and efficient. To assist this, the standard also proposes to introduce new requirements on sizing and controls for building services systems to reduce the risk of under or oversizing systems. 

In terms of continuous monitoring of the as-built performance of non-domestic buildings, the government has expressed their intention to continue using CIBSE’s TM39 as the standard for new buildings to be sub-metered and it is recommended that the forecast energy performance of non-domestic buildings should be modelled and provided to the building owner at completion stage for the purposes of energy benchmarking. This energy forecast is proposed to be based on the CIBSE TM54 framework and present monthly energy usage figures in metered energy broken down into fuel type and energy end-use category. 

So that covers Part L, now lets look at the uplifts proposed under Approved Document Part F, the government proposes that:

Measures are imposed to mitigate the transmission of infection via aerosols in certain non-domestic buildings ensuring good air quality for people in buildings. It is proposed that ventilation provisions are made to office buildings to be designed with additional fresh air capacity where additional ventilation may be required. It is proposed that each occupiable room in the building should be capable of providing fresh air at rate 50% higher than the Approved Document F minimum standard. This as a result will require larger mechanical ventilation systems. Additional minimum standards for ventilation in offices are also proposed as a rate per sqm of floor area to ensure that ventilation rates are maintained for variable levels of occupation. New standards have also been set for systems that recirculate air in offices and introducing a minimum ventilation standard of 15 litres of fresh air per person in occupiable rooms in all types of non-domestic buildings where signing, loud speech or aerobic exercise are likely to take place, where low temperature and humidity environments may exist or where members of the public may gather in large groups. 

The Future Buildings Standard also covers the standards to reduce overheating in new residential buildings which came into force under Approved Document O and covers:

The two methods of complying with the proposed new requirement of Part O include:

1. The simplified method and uses a combination of limiting unwanted solar gains and removing excess heat in order to reduce overheating risk. The requirement depends on the location of the new residential building. 
2. The dynamic thermal analysis method uses CIBSE’s TM59 Design methodology for the assessment of overheating risk in homes to demonstrate compliance with the new regulation for overheating. Both methods are described in further detail in the Approved Document

Now in terms of limiting solar gains, fixed shading devices, glazing design, building design and shade of adjacent permanent buildings, structures or landscape will be considered acceptable by the government as means of limiting solar gains and the preferred means of mitigating overheating is through passive means, (i.e. low or no energy needed), as far as practicable reducing the need for mechanical cooling and ventilation. Further guidance is provided in the Approved Document since this regulation is now live. 

The RIBA’s views on the governments current steps is that the 2022 uplifts were not as ambitious as hoped to be which they expected would introduce and regulate embodied carbon targets and better assess building performance to close the performance gap, but they seek to influence the additional uplifts to hopefully come into force in 2025. 

So to sum up what I discussed today:

• The Future Buildings Standard is designed to transition non-domestic buildings to use low-carbon heat sources for heating and hot water ensuring they are better for the environment and fit for the future aimed to be implement by 2025.
• The Government’s preferred option will deliver a 27% reduction in carbon emissions on average per building compared to the existing standard. It will also ensure that construction professionals and supply chains are working to higher specifications in readiness for the introduction of the Future Buildings Standard. 
• The standard is to be achieved through uplifts to Building Regulations Part L & F in regulating heat and ventilation and the government suggests splitting the different types of non-domestic buildings in relation to their water heating demand
• To monitor these changes and uplifts, the government has expressed their intention for new buildings to be sub-metered and the forecast energy performance of non-domestic buildings to be modelled and provided to the building owner at completion stage for the purposes of energy benchmarking.