Building Regulation Changes – The perceived impact!
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Written by Tom Kimber
Tom is an Associate Architectural Technician with BoonBrown offering expertise within the company on building regulations and technical standards.
You will be aware there are significant updates to Parts L (Thermal) and F (Ventilation), and two new documents, Parts O (Overheating) & S (Electric vehicle charging) of the building regulations that are coming into force on the 15 June 2022.
These are the most significant changes to the regulations in recent years.
Without going into the technical details of each change, Parts L & F have been revised and Part O introduced as an interim step to assist the Governments desire to get to Net Carbon Zero. Part S sets out parameters for electric vehicle charging.
For past changes to the regulations, there was an obligation to secure the building regulations application through the interim period by making a start on site. Now however this has been increased to a ‘significant start’ on site. Where previously the start on site could have been a very light touch, now the significant start is requiring that all the footings for the development are to be poured, or the site drainage for the scheme is to be installed.
We have been seeking clarity from local authority building control, private assessors and the NHBC and the uniform response is that if you have a site of 1 or 100 units, the footings or drainage of all the site will need to be installed by 15 June 2023 if you have a building regulation application running before this year’s deadline.
This would include all phases of a large, phased site, where previously if regulations changed then the plots not yet started would still be built under the older regulation set.
As a practice we are experiencing a desire from clients to submit building regulation applications prior to 15 June 2022 to ensure that the current regulations can be built to, giving the year’s grace to get the footings for the site poured.
The new regulation changes will now introduce a higher level of thermal performance and airtightness to the building fabric, improving the ventilation strategy and assessing and limiting the overheating (solar gains) within a building.
For example, in Approved Document L domestic external wall U values have been tightened to 0.18 W/m2/K, ground floors to 1.3 W/m2/K and roofs to 1.1 W/m2/K.
Within Approved Document F the air permeability for new build residential has been reduced to 5 from 10m3/m2h. Whole building ventilation rates have also increased.
These changes will not be overly difficult to achieve in themselves. As a practice we have been working with very similar U values over recent years on a wide range of projects where planning permissions have already required a betterment of the existing regulations, and in our experience with air tightness, with good site control most of our projects have achieved below 5m3/m2h in their air tests.
Approved document ‘O’ is principally directed at new build residential units, although does include live/work premises and is the driver for looking at the solar gains and improving the removing the excess heat within the home.
The known impact of this is that the likely input of a thermal modelling specialist at a far earlier point of the project. Currently, it is likely that the earliest point that many consultants are employed is once planning has been approved and a project is moving into the working drawing package stage.
The implications of the new regulations will require design teams to seek guidance from thermal modelling at a far earlier project stage.
If this isn’t actioned, then there is a risk that once planning is permitted and the next stage of the design development progresses, there will undoubtedly be the requirement to go back to planning to adjust the designs, adding in time and cost to the client.
Approved document S seems to regularise the addition of electric vehicle charging points on sites. It is the first approved document to my knowledge to introduce a financial cap as a defined figure. This does not appear to be related to an index linked increase, so time will tell how this document will be affected by the cost-of-living increases that the country is currently experiencing.
It is understood that although we are very close to the new regulations being adopted, the final SAP software is yet to be officially distributed to the SAP consultants. Many will have had a chance to see the ‘Beta’ testing version, but the final issue is still to be released.
As a practice with an office in Somerset, we wonder if there will be a delayed impact on planning due to these regulation changes principally due to the current phosphate and nitrate issue affecting the Somerset levels and their catchment area.
What about schemes already submitted for a planning permission?
For the last couple of years many planning applications in Somerset have been in stasis until the phosphate and nitrate stalemate has been concluded.
These will all have been designed based on the principles of the current building regulations, and the perception is that once the planning is released, many sites will need to be appraised against the new building regulations with the probability that planning will need to be resubmitted.
For any projects going through the planning process, it could be recommended to submit your Building Regulations application before the 15 June 2022, as this can be done with just the planning application reference number and a limited set of drawings (site plan, building plans and elevations).
This would provide the year’s grace on having to adopt the new changes, however in Somerset would still be dependant on the Phosphate issue being concluded and the planning permission being granted.
With significant updates like this there will be a period of settling into and understanding the changes and their impact.
No doubt, the next 12 to 18 months will be an interesting time whilst consultants, manufacturers and clients all start to piece together the changes required.
Energy saving through Retrofit
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Over the last few years there seems to have been an increased awareness of climate change and the environment, this together with the Government’s 2050 Net Zero CO2 emissions target has led our industry to consider new ways to make buildings more efficient, less reliant on fossil fuels, and promote renewable technologies. The current energy crisis due to soaring fuel costs is also making us more mindful about where our energy is coming from and the need to be less wasteful with it.
Can green buildings work for us to solve this issue?
Incorporating technologies into new build has become common place for most sectors, with the most efficient method of creating new ‘green buildings’ being to utilise the three steps below.
Keep the cold out
Using modern methods of construction focusing on a highly insulated and airtight envelope ensures that heat is retained and prevented from escaping, therefore minimising the need for additional space heating.
Recycling waste heat
Waste heat recovery systems, including Mechanical Ventilation and Heat Recovery (MVHR) and waste-water heat recovery technologies ensure that waste heat is recycled, providing warmth to fresh air reducing the energy demand for heating.
Renewable technology
Finally using renewable technologies such as Solar Panels, Solar Thermal and Heat Pumps can generate energy, store it and even sell it back to the grid in some cases.
The upfront costs of building this way can be greater than traditional constructions, however the technology used can create savings over time which outweigh the initial outlay. The technologies are continually reducing in cost as they become ever more mainstream.
So new buildings can benefit from this type of approach but what about existing buildings?
Existing commercial, industrial, and institutional buildings can benefit substantially from the same ethos employed above and also carry the benefit of utilising their existing building structure, retaining all the embodied carbon and the savings that come with it.
This type of upgrade to an existing building is referred to as a Retrofit and a key part of the design is to employ a whole building approach. This is a holistic assessment of the entire building fabric in conjunction with a specialist Energy Consultant who will thermally model the building to identity and highlight the key areas to be targeted.
Replacing existing heating systems with renewables, swapping old lighting to LED fittings, improving the thermal performance of the external envelope, and introducing solar technologies will all contribute toward targeting Net Zero Carbon.
There are differing levels of Retrofit from a light touch to much deeper approach and each offers vary degrees of benefit Vs cost. It is worth noting that some existing buildings will not be suitable for Retrofit due to their age or construction, so not every project is suitable. The detail of the design and installation is key to ensure they work in harmony together, and it’s critical that projects are both designed and installed by professionals.
Putting theory into practice – Beaucroft College Wimborne
BoonBrown have been working recently with a team of consultants on a Retrofit project for a Special Educational Needs or Disability (SEND) facility in Wimborne, Dorset on behalf of Dorset Council. The project will be one of the first in Dorset to benefit from SALIX funding which is a government backed scheme to provide public sector projects with funding to reduce carbon emissions, lower bills and improve energy efficiency.
The site is the former Wimborne First School which consists of a group of buildings with notable architectural merit, unfortunately the buildings have been vacant for several years. Parts of the school are over 100 years old and have been subject to several adaptions over its life. The buildings have a number of the original features which are considered important to the setting of Wimborne and need to be retained.
A thorough assessment and survey of the existing building was undertaken to understand the existing structure, materials, and fittings. We worked with an Energy Consultant to identify the most cost effective and beneficial Retrofit adaptions for the building, which included the three steps we outlined above.
Keeping the cold out
The Retrofit follows a whole building design strategy with a fabric first approach which aims to exceed the current building regulation standards. This consists of thermally upgrading the accessible external fabric of the buildings, increasing air tightness, and replacing the existing single glazed doors and windows with double glazed units.
Recycling waste heat
New heat recovery units (MVHR) within the classrooms will increase the amount of fresh warm air in the buildings, improve internal comfort levels while providing excellent ventilation.
Renewable technologies
The existing heating system is a very inefficient gas boiler which is not fit for modern purposes. This is to be replaced with an extremely efficient air source heat pump and solar voltaic panels placed on each of the south facing roofs which will reduce energy bills and help further reduce C02 emissions.
It has been calculated that retrofitting the existing buildings to current building regulation standards will reduce C02 emissions by approximately 77%.
As with the new build route, the key to making this type of refurbishment work is ensuring the details of each inclusion and system is designed and installed correctly so everything works harmoniously. Crucial to this is that the works on site are carried out by skilled contractors and that the technical detailing is followed to ensure the benefits of the Retrofit method are realised.
