In July the Building Research Establishment (BRE) published a new SAP methodology called SAP 10. SAP calculations are used to demonstrate the energy performance of dwellings in the UK and produce EPCs.
Following the Independent Review of Building Regulations earlier this year, a revision to Part L of the Building Regulations is expected in 2020. The current methodology, SAP 2012, will continue to be used until then.
We’ve put together a summary of the key changes and the likely implications for businesses:
Fuel prices and CO2 Factors
The CO2 emission factor of electricity has been reduced significantly from 0.519 kgCO2/kWh to 0.233 kgCO2/kWh – only slightly higher than mains gas (0.210). This is to reflect the significant increase in renewable energy production for the national grid since the last update. The change is aimed at encouraging dwellings to move away from fossil fuels.
Heating Pattern
It had previously been assumed that people were home more at weekends, and thus using more energy. Recent studies have shown this to be inaccurate; SAP 10 therefore applies the same usage pattern to weekends as weekdays (07:00-09:00 & 16:00-23:00). This consistent pattern for all days of the week will reduce anticipated energy consumption.
Lighting
Lighting has had a significant overhaul as the current data requirements are very minimal, no more than a simple counting exercise with fittings either being classed as “low energy” or not. SAP 10 will require data on power and efficacy, similar to the existing non-domestic methodology. Poor use of daylighting, as well as insufficient or excessive lighting generally, will be penalised.
Thermal Bridging
Default values have been increased in an attempt to discourage quick, inaccurate calculations and encourage detailed analysis of junctions. This means a lot more work for those early design indications with bespoke calculations potentially being required for every junction.
Hot Water Demand
SAP 10 requires assessors to input the number of baths and showers in a dwelling. The flow rate and type of shower will also be required, with electricity usage from instant electrical showers now being accounted for. This is likely to increase anticipated energy consumption.
Photovoltaic Panels
SAP 10 will allow for PV storage, either in the form of battery storage or excess electricity being used to heat an immersion cylinder. This is an improvement on the current methodology which assumes half of all electricity generated by PV is returned to the grid. However only dwellings with their own inverters will be able to claim any reductions from PV. Blocks of flats with only one inverter between them will now be excluded. Over shading will also be stricter. Given that PV is often used to offset the higher electricity carbon factor, its reduction may balance things out overall.
Overheating Risk
Criteria for overheating risk have been tightened. Assessors must record if there are any noise or security issues associated with leaving windows open. If so, fully openable windows can no longer be assumed to be an appropriate ventilation method and only trickle vents may be used in the calculation. Mechanical ventilation may need to be increased.
Thermal Mass Parameter
Currently assessors can select “low”, “medium” or “high” for the thermal mass of a building. In SAP 10 a bespoke calculation will be required for every development, adding extra time to the calculation.
You can download the full methodology on the BRE Website.
For more information on how the changes will affect you, please contact us.
To mark INWED22, we spoke with some of our women engineers about what made them decide to be engineers, and how their careers are developing with CWC:
Ellie Schofield
Building Performance Engineer
Time at CWC:
2 years, 11 months
Was engineering presented to you as career option in school / college?
No, engineering was not presented as an option to study at my school and the careers available in the sector were not discussed. I was influenced by a family member and a tutor at college that engineering / construction could be a rewarding career, and then became very interested in sustainability within construction whilst at college.
What’s your favourite part of your job?
My favourite part about my job role is feeling like I can make a difference. Due to the negative impacts of global warming at the moment, we work closely with clients to reduce CO2 emissions, which will, in the long run, have a positive impact on the environment.
What is the most valuable lesson you have learnt during your studies and career so far?
My most valuable lesson so far has been to do what I want to do, without the influence of others. For example, I didn’t have any friends studying a construction or engineering-based course when I started my studies, but did it anyway as I knew it was what I wanted to do as a career.
What do you think puts women and girls off engineering / construction?
I don’t believe females are necessarily put of the idea of working in the industry, but they are not given advice on the opportunities in the same way that males are. Therefore, I think this leads to many females not having the confidence to go for an education or job role within the sector.
What do you think the industry can do recruit more women?
I believe the industry should aim to work more closely with schools, to ensure that children understand the roles within the construction and engineering sector, so girls know from a young age they can take an engineering career path.
What advice would you give to girls considering a career in the construction industry / engineering?
The advice I would give is that females can be successful in the construction / engineering industry, it does not matter what gender you are. If you are interested and willing to learn, anyone can build a good career.
Jessica Seddon
CAD / REVIT Technician
Time at CWC:
3 years, 10 months
Was engineering presented to you as career option in school / college?
In all honesty, it wasn’t. It was something I looked into myself along with other similar roles such as architecture. In high school student were also pushed strongly towards university, with apprenticeships and work-based learning routes really downplayed. They unfortunately had a reputation of being only for ‘naughty’ or ‘less intelligent’ students, which is completely incorrect!
I imagine things have improved since 2012 when I left school. I really think that if we want to bring more women into the industry that’s where it starts. At that age when students are thinking about their careers, we need to help then identify the best way to get there.
How have you developed in your current role?
For the past two years I’ve been steadily managing the CAD/RVT/BIM workload within our Liverpool office. I am progressing away from the standard expectations of my role as a technician and more into a lead/management role, which I have been enjoying a lot.
For me it has felt like the natural progression of my career path. I enjoy the challenge and balancing the changing workload. I want to help develop and improve processes and understanding, for myself and the business as a whole. I am passionate about what I do, and I want that passion to translate into the quality of end product CWC puts out there.
What role do you think digital engineering will play in the future of the construction industry?
I really think that Revit and the process of BIM is still being underutilized industry wide. The potential is there for truly collaborative design and I hope to see everyone across the construction industry invest a lot more resources into understanding it.
I feel in our industry that communication can be lacking between different parties involved in a project, and that slows things down. This is where I think Revit and the 3D Collaborative design process can be utilized to its fullest. I’d like to see more projects using cloud based services such as BIM360, where all disciplines feed their model information into one central file.
This level of collaboration does pose its own unique challenges, and it is very different from the standard information releases used across the industry at present. But it has so many advantages, and if used correctly it helps the 3D modelling process to aid pre-emptive design, helping to eliminate problems that could arise in the construction phase early on.
To me, this is what Revit should be used for. It’s a fantastic bit of software that is so much more than just 3D coordination and making nice looking renders for presentations.
