Construction Leadership Council – study into labour markets & off-site

This blog was written by BSRIA Chief Executive Julia Evans

This blog was written by BSRIA Chief Executive Julia Evans

Exciting times: leading on from BSRIA’s press statement issued on 3rd February: the Construction Leadership Council (CLC) has been asked to undertake a “major” labour market study by skills minister Nick Boles MP and housing minister Brandon Lewis MP.

BSRIA is encouraging member and industry input from to the accompanying CLC consultationconstruction industry labour model study

Evidence to: construction.enquiries@bis.gsi.gov.uk

Deadline: Monday 29th February 2016.

The CLC has invited Mark Farmer of Cast Consultancy (formerly Arcadis) to lead the study, culminating in a report for CLC’s consideration in the spring. It will both: reflect on the impact of the current “labour model” in construction and make recommendations for action by the industry and government to help overcome constraints on skills development and the sector’s capacity to deliver new homes and infrastructure.

In particular, ministers want to know whether there are structural issues and risks that diminish long-term incentives for smaller subcontractors, who employ the largest part of the sectors workforce, to invest in training.

As I said earlier this month: BSRIA is very much supportive of this commission and consultation and, on behalf of the industry and our members, wishes to be involved every step of the way. Such commission hasn’t come a day too late, especially with rising demand especially, but not only, in the house building sector.

Alternative delivery methods – such as off-site – with a fresh skills base and capacity to bring new entrants to home building supply chains signifies a “shifting focus”.

 The consultation requests:

  • Evidence of how the construction labour model and recruitment practices impact on incentives for skills development in the sector (including in the supply chain) and on the introduction of more novel techniques such as off-site construction.

Evidence on how the current model works – including:

  • What business models and other arrangements could better support skills and skills pipelines in the sector?
  • What measures could improve wider incentives for capacity investment and the introduction of new ways of working?
  • What are the barriers and enablers to greater use of off-site construction?
  • How could the range of participants in the UK housing market be broadened, including through the better introduction of institutional funds?

So, I urge “one and all” to take a few minutes to put “comment to keyboard” for this crucial study. Remember: little can change without your expert opinions!

Betting on the general election? Think again

This post was written by Julia Evans, BSRIA Chief Executive

This post was written by Julia Evans, BSRIA Chief Executive

There are number of ways of predicting the outcome of the general election and an equal number of ways of being wildly incorrect. Bookmakers across the land are considering the 7th May to be a field day equal only to the Grand National in terms of punter cash finding its way through the betting shop door and not finding its way out again.

The one thing that seems sure is that the outcome is likely to be uncertain with both a three way coalition and a rerun of the election in the Autumn both being seen as possibilities.  So, where does that leave construction and building services?

Just as education and the health service are perennials in political manifestos so construction has some constant themes. Although construction rarely makes front page news there are a number of issues that seem likely to make the political headlines. Maybe for reasons of one-upmanship, as in who is promising to build the most houses? It’s the Liberal Democrats, since you ask; who are promising 300,000 new houses a year and an assurance that they’ll all be energy efficient. Or the startling alignment and collaboration between the three main political parties who are promising to work together on climate change, which in itself is surely not a bad thing?

But what of the perennials that effect construction?

Representation at senior levels seemed threatened at one point by questions being asked about the continuation of the role of Chief Construction Advisor, this is now resolved at least for the next two years. However other things are less easy to solve – the impending skills shortage, the delivery of low carbon retrofit and the lurking influence of increasing devolution will all play their part. As will continuing pressure on late payment practices, poor treatment of supply chain and the weakening of centrally funded research programmes.

The uncertainty caused by the impending election has been felt in the slackening of demand for construction since the turn of the year, the recent results of our quarterly consultants survey suggested that there has been a halt in new work as we wait for a new government. This has also been seen in a reduction in the immediate pre-election period of house building starts just at a time when we need to be addressing the national shortfall.

So back to my punt at the bookies, I think I will put my money back in my pocket and find something more predictable to spend it on, maybe something in preparation for the barbeque summer?

Using Robotic Total Stations to drive down the cost of construction

Since the days of the Latham report in 1994 there has been a desire to cut the cost of construction, mainly by finding more efficient ways of doing things. Of course, there will always be people who stick rigidly to the principle that ‘the old ways are the best’, but there are many more who are more open-minded – not least in terms of making use of new technologies.

Having said that, there is one particular technology that has not yet been embraced in the UK, despite the significant financial and time benefits that have been shown time and again in the USA and other countries.

I am referring to the use of Robotic Total Stations (RTSs) for laying out building services – as an alternative to the traditional ‘tape measure, spirit level and theodolite’ approach.

This blog considers the limitations of traditional methods and explains how RTS technology can help to overcome them. It also explores some of the reasons that this technology has not yet been widely adopted in the UK.

Are the old ways the best?

Traditionally, the layout of building services on site has involved a team working from the building drawings, using a tape measure, spirit level and theodolite to identify attachment points for pipework, cable trays etc.

Unfortunately, this system doesn’t work particularly well with complex buildings, buildings with curved walls, buildings with prefabricated materials, BIM or non-orthogonal spaces. In fact there is a huge margin for error, resulting from the following challenges:

  • Ensuring the reference point is right
  • Making sure the tape measure doesn’t move
  • Making sure the string doesn’t move on arcs
  • Ensuring the theodolite is level
  • Making sure the degree in which you are measuring is exact

Every small mistake can lead to potentially serious consequences. For example, being a few degrees out on an angle can mean that pre-fabricated systems don’t fit when the time comes to install them.

Similarly, incorrect layout can result in clashes with other building elements or services, thereby disrupting the construction schedule, generating remedial works and wasting materials, time and money.

Even when everything goes smoothly, the traditional approach is laborious and time-consuming and any delays can affect the work of other teams.

Plus, when changes need to be made, methods of recording reasons (obstruction etc.) and evidence (photographs etc.) are recorded additionally to any drawings they are working from.

These reasons are sometimes reported to the design team (if there is one) to amend the drawings or model; at other times, these records are filed separately for the purposes of finger-pointing at a later date.

Either way, it takes a long time for this information to be reflected in the designs, if at all, which means other contractors or labour forces won’t see the changes until they’re updated.  Working from paper also has the potential for loss or damage.

Furthermore, these issues are going to become more serious with the wider use of Building Information Modelling.

An alternative approach

Robotic Total Stations (RTS) allow layout to be completed by only one person, rather than the classic layout team.

To begin construction layout, a tablet with software controls the RTS and is loaded with a 2D drawing or 3D building model. Site survey points from the job site are identified in the model and are used to locate the RTS on the project site and in the model.

Once the RTS is located, the person operating the RTS can view the model on the tablet computer and select the points to be marked.  Once selected, the RTS will tell the operator their precise distance from the point (if using a stake) and then guide the user to the point with directions indicating forward/backward or left/right movement.  The operator then stakes the mark and moves to the next one.

A more advanced RTS feature is Visual Layout  which marks the layout point with a laser (removing the need for the stake); the operator then only has to follow the laser to each point and mark the location.

Basically, the RTS does all the work while the operator follows its laser, marking each point to within a distance of millimetres from the 2D/3D model point.

This can be used for the accurate positioning of multiple trades at the same time, ensuring no delays on site.

So what are the benefits?

Improved efficiency.

RTSs use the same 2D drawings or 3D building models as other trades involved in the project, so collaboration is simpler and quicker.

Enhanced accuracy.

Layout coordinates can be accessed directly from the building model and changes to layout positions can be recorded at the time of layout and documented with reasons and photographs.

Fewer mistakes.

The RTS works directly from the building model. There are no manual measuring processes involved. Points to be marked are extremely accurate and their purpose is referenced to the operator via their tablet device.

Reduced paperwork.

Using the RTS on a job is a paperless process, meaning there is no risk of losing documents or spilling coffee on them.

Reduced labour costs.

The RTS only needs one person to operate it and that one person is also capable of increasing layout productivity by up to five times.

Improved quality control.

RTSs can be used as a sophisticated tool in a QA/QC process, both pre- and post-installation.

BIM-to-Field

As we move to more sophisticated BIM processes – such as 4D & 5D BIM that includes building production models and which consider the constraints of a construction site (equipment capacity, working methods etc.), model based estimating and more – a live link to the field is needed.

This link, in part, can be provided with the use of an RTS, allowing responsible parties to track works as they are completed and referenced against the original model, applying changes where necessary and allowing the tracking of works ready for access by the next stage in the construction process.

So why aren’t we using them?

Companies across the US have used RTSs on construction sites for many years now. They’ve been highly popular with MEP contractors and revolutionised layout processes and BIM progression; so why don’t we use them?

A lot of it simply comes down to misconceptions about the technology and its uses.

Return on investment.

Implementing RTS technology requires capital investment and many companies feel that because they don’t have dedicated layout teams they won’t see a good return on their investment.

However, the relative simplicity of RTS technology means that any member of the MEP team can carry out accurate layouts, so the contractor can make better use of the workforce.

Also, RTS eliminates manual errors so that the most highly skilled and best trained individuals can be allocated to the more complex tasks, while lower skilled operatives do the laying out.

In addition there are considerable time savings that could ultimately reduce the number of operatives required on the project, thus reducing labour costs.

You can calculate your own ROI here

The savings cited for RTS do not have any real impact on the bottom line.

This is simply not true. Savings from the use of an RTS can be seen in:

  • Reduced remedial works due to increase in QC/QA documentation and recording – an immediate reduction in cost.
  • Improved efficiency whilst on site – reduction in labour cost.
  • Fewer errors in MEP element locations (another remedial work saving) – an immediate reduction in cost.
  • Reduced resource required to complete works – an immediate reduction in cost.

MEP designs evolve during installation so that the drawings do not represent the actual situation.

Perhaps this is true today, but if you are working this way now, you won’t be for long. For medium and large projects MEP data and detailed design will be as essential as structural design as the industry assimilates the BIM process.

UK BIM deadlines are looming now and businesses looking to grow, or large businesses looking to remain profitable, will need to ensure they can work in these parameters – and soon.

Clashes between services do not occur when the same contractor is doing all of the MEP work.

On small projects it is often possible to ‘work around’ any clashes between services. However, on larger projects it is not enough to ask for one element to be placed over/below/around another, as this may then run into a second clash with a third element.

This second work around would involve a wider rectification, which may infringe on another element, and so on until a solution cannot be made.  Eventually, it may occur that an MEP element then interferes with the installation of another contractor’s or team’s work.

Also, when ‘working around’ an issue, we create problems when considering building maintenance post-construction, as MEP elements will deviate from their logical course.

UK construction techniques do not lend themselves to using an RTS.

While it’s true there are some differences between UK and US construction methods, there are many more areas where RTS can deliver the same benefits to UK contractors as it is already doing for US contractors.

Conclusion

While any investment in new technology clearly requires careful consideration, I hope it is now clear for the reasons stated above that RTS is certainly worthy of that consideration. The potential benefits to MEP contractors are enormous, so surely it’s worth taking the time to keep an open mind and take a closer look.

Follow this link to see a demonstration video or, if you’d like to see this technology in action, book onto a Trimble road show event to compare this with a traditional approach.

Author Profile
This blog was written by Chris Slinn, MEP Business Development at  Amtech, a Trimble company, a manufacturer of specialist software for the building services industry.

The BIM Level 2 jigsaw – nearly complete?

The Level 2 programme was defined in the BIM Strategy which is available at  www.bimtaskgroup.org

The Level 2 programme was defined in the BIM Strategy which is available at
http://www.bimtaskgroup.org

In my blog article back in June  I discussed how the UK Government had refined its Level 2 BIM requirement and express it in the form of compliance with seven components:

  1.  PAS 1192-2:2013 Specification for information management for the capital/delivery phase of construction projects using building information modelling
  2. PAS 1192-3:2014 Specification for information management for the operational phase of assets using building information modelling
  3. BS 1192-4:2014 Collaborative production of information. Part 4: Fulfilling employers information exchange requirements using COBie – Code of practice
  4. Building Information Model (BIM) Protocol
  5. GSL (Government Soft Landings)
  6. Digital Plan of Work
  7. Classification

Since then BS 1192-4 has been published, leaving just the Digital Plan of Work and Classification elements to be completed.  As reported previously, these were the subject of a TSB-funded competition and I thought it would be useful to give an overview of how the competition went and where it is now.  This is a fundamental piece of work that is set to have a huge impact on BIM in the UK and it is vital that as much of the industry as possible has an awareness of what is happening, and get involved wherever possible to help make it a success.

The competition brief was developed, with industry consultation, and has been administered via the Innovate UK (formerly TSB) SBRI programme under the title “A digital tool for building information modelling”.

The competition process involved two phases – Phase 1was a feasibility study, with organisations or consortia invited to submit proposals with funding of up to £50k (including VAT) available to each.  Three teams were awarded these phase one contracts:

  • RIBA Enterprises Limited, together with BIM Academy, BDP, Laing O’Rourke, Microsoft and Newcastle University
  • BRE Global Limited, with buildingSMART UKI
  • CIBSE on behalf of a group of industry professional bodies known as C8, consisting Association for Project Management (APM), British Institute of Facilities Management (BIFM), Chartered Institution of Building Services Engineers (CIBSE), Chartered Institute of Building (CIOB), Institution of Civil Engineers (ICE), Institution of Structural Engineers (IStructE), Royal Institute of British Architects (RIBA) and Royal Institution of Chartered Surveyors.

The results of the Phase 1 stage can be seen here.

On completion of Phase one, two of these submitted bids for Phase 2 – RIBA Enterprises Limited and BRE Global Limited, and RIBA Enterprises Limited was awarded the single Phase two contract.

At the time of writing, the results of the Phase two competition had not been posted on the Innovate UK website so it has not been possible to compare what RIBA Enterprises has said it will deliver with the functional specification.

As RIBA Enterprises has developed Uniclass2, which it uses for some of its other software tools, it is probably safe to assume that the classification solution delivered as part of this competition will be based on that format.  That being the case it will be interesting to see how Uniclass2 is developed to cover all necessary instances, and not just those which may occur within the 3D model.  The classification system needs to be capable of capturing everything which may be held within the common data environment (CDE) in order to make the objectives of the standards such as PAS 1192-2 and PAS 1192-3 a reality – the PIM during construction and AIM during operation being the sole sources of information for further use, having been verified and validated against the EIRs and OIRs.

Many experienced BIM practitioners recognise the need for a comprehensive classification system to make information available throughout the life of an asset, letting it be used time and again rather than having to recreate it, and this project could make this a reality.  However, careful thought needs to go into it to make sure that everything that needs to be classified can be, and in a way that can be understood.

Safety in Building Services Design

This is a guest post by Richard Tudor of WSP

This is a guest post by Richard Tudor of WSP

Space, and the cost of providing space, for plant and building services  distribution is at a premium and designers often come under pressure to reduce the spatial requirements for building services installations. In order to discharge their obligations, designers must take care to provide safe means of access for installation, maintenance and equipment replacement.  In addition designers need to be aware of the regulations and legislation requirements that a design may impose on the installer and end user as a design solution can often impose additional legal

responsibilities, particularly in undertaking associated operation and maintenance activities. However, the active and continuing attention to safe access issues, throughout the design stages, is not always achieved as the designers’ attention can often concentrate on what is perceived to be more immediate concerns.

BSRIA’s publication Safety in Building Services Design BG55/2014 has just been published which provides guidance on designing for safety in both new and refurbishment projects.

The publication is aimed at designers and includes information on:

  • relevant legislation including CDM
  • hazards and risks including managing risk in the design process
  • understanding space requirements and access provision
  • designing for maintenance
  • plant room design
  • communication of risk information including representation of risk information on drawings
BG55/2014 Safety in Building Services Design

BG55/2014 Safety in Building Services Design

However, the diversity in type, configuration and possible location of plant, means it is not possible for this publication to give definitive guidance for all installations.

The publication provides a practical guide to assist the design process, aid design reviews together with providing a better understanding in designing for safety.  For example, included in the publication is a checklist on the considerations in designing for health and safety which can be used as part of the technical design quality review process.  In the pdf version of the publication this is included in an editable Excel format. Influencing factors, considerations and space requirement data useful in the design decision process with respect to providing safe access are highlighted in the publication.

The poor provision of safe access for maintenance could result in an increased likelihood of cutting corners or omission of maintenance and repair activities. This in turn, could result in building services failures that could adversely affect safety, legal compliance, productivity and quality of the environment.

BSRIA launches a new course on the 12th November 2014 providing guidance in designing for health and safety in the space planning of building services with respect to operation, maintenance and plant replacement. The course is intended for professionals involved in the design of building services but is equally relevant to contractors and other professionals within the industry. Young engineers in particular would benefit from the course.

On completion of the course delegates will be able to:

  • understand the specific considerations with respect to designing for safety for building services
  • identify discipline specific considerations in designing for safety
  • challenge designs in relation to health and safety in the design, construction and operations of building services so as to improve performance
  • understand relevant H&S legislation, codes of practice and guidance
  • understand the relationship between building services design and maintenance operations
  • understand the management of hazard and risk together with control strategies
  • locate information relating to health and safety to assist in design process
  • understand the consequences of failing to manage health and safety effectively
  • understand the importance of communication and provision of information in the design process

Richard Tudor is a Senior Technical Director at WSP and has been an integral part of the WSP Group Technical Centre for over 14 years. His responsibilities include technical quality, specification development, technical knowledge management, delivering training, designing for safety, providing technical support, and improving project delivery.

Designing for change

Ian Harman of Marflow Hydronics (BSRIA Members)

Ian Harman of Marflow Hydronics (BSRIA Members)

With the industry moving at such a fast pace, new innovations are being introduced all of the time. Manufacturers are inventing great new products that offer many benefits; solving the problems of the present to provide a better future. The biggest problem that they face, though, is launching these products on to the market. This is where BIM could really help. 

I think it’s fair to say that people don’t really like change. We like to stick to what we know and what we feel comfortable with. This seems to be the case in our industry. Many people, from consultants to installers, are still completing jobs and planning projects in the same way they’ve been doing it for years; that is in very traditional ways. A prime example is how there is still much use of two port control systems despite Pressure Independent Control Valves having been around now for quite a while. These newer products are faster to implement and more reliable in the long term, yet there is still a reluctance with some people to adopt the new technology.

It’s true that with any new product there’s inevitably a big learning curve to using them, and often training can be time consuming. There’s also the fear of risk. If people use a new product that they’re not so familiar with then there’s always the chance that it will go wrong. This could be because the user isn’t so experienced at using it, but also it could turn out that it wasn’t the ideal product after all and sometimes knowledge and experience can really help when making decisions. This is where BIM steps in.

Using BIM, manufacturers can create models, which I like to think of as ‘Lego blocks’, that they can send to customers to introduce them to a product. And they can do this long before any decisions have been made, at the very initial stages. The ‘Lego block’ would be a visually simplified model that not only clearly defines the spatial envelope and connection points, but also includes a wealth of ‘metadata’. This ‘metadata’ contains data fields specific to the particular products, such as flow rates for valves or electrical loads for powered devices.

BIM - Marflow Hydronics
That all means that clients can look at the products in detail and trial them in their plans from the very beginning. They will be given the time to properly analysis products and see how they will work within the system and how they will interact with other components.

By starting with the end in mind and properly understanding the system at the initial stage, it will help to future proof the project far down the line. It’s also the cheapest time to detect any issues. The easiest time to make a design or selection change is at the beginning of a project and BIM facilitates this in a much more user friendly manner than ever before. This would undoubtedly give them much more confidence in the products they’re looking to use and would, very importantly, remove that fear of risk.

BIM provides users with the time and ability to put much more thought into their projects earlier on, minimising that risk further down the line. This then increases the chance of far more successful project that works with the best products, potentially the latest and more developed ones, and there’s much more chance of it being on time and to budget.

BIM 2 - Marflow HydronicsManufacturers, like Marflow Hydronics, have been doing this to help bring new products into the limelight that otherwise customers may have been apprehensive about. More importantly, this has helped all parties get the right products specified when they may not have been otherwise. BIM may be the ideal solution to help us move more quickly into the future using more innovative products and having many of the niggling issues that have been around for so long vastly reduced, if not eliminated.

This was a guest post by Ian Harman, Technical Applications Engineer at Marflow Hydronics, BSRIA Member

If you are looking to find out more information about BIM, BSRIA runs two specific training courses:

There are also several other blog posts focused on BIM as well as a BSRIA BIM Network. 

Best & Worst Practices Please!

Julia Evans, BSRIA Chief Executive

Julia Evans, BSRIA Chief Executive

BSRIA recently held a workshop on behalf of DECC identifying priorities to promote low carbon heating and cooling in non-domestic buildings as part of the development of its low carbon heat strategy.  Attendees were drawn from both the Young Engineers and Energy and Sustainability BSRIA networks.  Personal thanks to AECOM’s Ant Wilson for chairing the event.

It was a busy day.  It recognised that both new and existing buildings have a pivotal role in reducing greenhouse gas emissions, and by 2050 one of the key requirements will continue to be how we provide heating and cooling.

BSRIA’s Peter Tse and Ian Orme both gave excellent presentations which drew on both good and poor practices identified from more than 50 independently assessed case studies.  These, I felt, answered the questions “what does good practice look like”, as well as “what are the consequences when its not followed”.

The workshop session resulted in many suggestions as to priorities for the future.  There were a couple which caught my eye.

In response to the suggestion that one of the priorities for DECC should be identifying independently assessed best practice and developing exemplars of new technologies, a number of delegates felt that instances of “bad practice” were even more helpful.  It seemed to me that a priority for at least a part of the audience was to know what to avoid doing.  Perhaps this reflects the industry’s receptiveness to messages about risk, and that we often learn most when we make mistakes.  The emphasis on “independent assessment” also resonated.  Many have become sceptical about instances of self-identified “best practice”, and BSRIA’s independent guidance on what works, and what does not, is there to assist the industry do things better.

Another of the workshop themes was on “skills shortages”.  After many years of recession, construction companies have euphemistically “right sized”, and this means that we have lost a lot of great talent from the industry.  Now that there are green shoots of recovery in construction, there is already talk of an exacerbated “skills gap”.  This gap makes it even more challenging for the industry to deliver buildings which meet the needs of their occupiers and where innovation is required to help tackle climate change, and meet the UK’s commitment to “zero carbon” and “very low energy” buildings. This reminded me of another of BSRIA’s strengths – training provision.

BSRIA's 2014/15 Training Brochure

BSRIA’s 2014/15 Training Brochure

Finally there was an astute observation that our recent quest for low carbon buildings has meant that we have worried less about the efficient use of energy, with the net outcome that we can end up with an EPC A rating for carbon design, but a DEC G rating for energy in use.  The move to policies that move us to buildings which are both zero carbon and nearly zero energy use will hopefully remedy this, although I suspect this particular journey may contain further unintended consequences before we reach that goal.

The workshop identified many requirements if we are to create environmentally conscious buildings that meet user needs, and importantly maintain these elements over the life of the building.

BSRIA’s mission remains to “make buildings better”.  As part of my role, I’m listening to our members and the industry what they expect from BSRIA.  I’d like to extend this offer to you, so if you have ideas about BSRIA’s future role, please send them to me: Julia.evans@bsria.co.uk.

To learn more about the BSRIA workshop you can download all the presentations from our website. 

Design Framework updated to reflect the new RIBA Plan of Work

MEP deliverables during old and new Plans of Work

MEP deliverables during old and new Plans of Work

BSRIA’s highly regarded Design Framework guidance has just been published in its fourth edition as BG 06/2014. This version brings the guide up to date in its reference to the latest RIBA Plan of Work. This article summarises some of the key changes that have been made to Design Framework in this latest edition.

Design Framework now aligns with the new project stages, designated 0 to 7 rather than A to L, that were developed as part of the Government’s BIM Task Group work. These stages are more explicit in their support of collaborative working amongst the project team and place more emphasis on handover from construction to operation and on the in use phase. In addition, there is now a new Strategy stage, Stage 0, deliberately to give clients and portfolio managers the chance to consider the proposed project in the wider context of their whole built estate.

Many of the new stages align to old stages, or pairs of old stages. For example Stage 1 maps to the old Stages A and B, Stage 2 covers the old Stage C, and Stage 5 is the equivalent of the old Stages J and K. But there is a significant disconnect between the end of new Stage 3 and old Stage E. Stage 3 is expected to conclude with agreement between the main design disciplines about the volumes allocated to each designer such that these provide feasible system boundaries. The idea for this is that once these volumes are agreed, each discipline can go away and work up its detailed design more or less in isolation. Provided they stay within the boundaries of their agreed volume then all should be well when it comes to spatial co-ordination.

These changes to the overall structure of the Plan of Work have meant changes to the design activities listed in the BSRIA BG 06 pro-formas, and also some changes to the stage deliverables. As can be seen from the table, the first formal deliverables under the new Plan of Work regime have been brought forward to an earlier stage than previously. In BG 06 the exemplar 3-d models to illustrate the new end-of-stage deliverables have been updated and isometrics included. For the Stage 3 deliverable, the 2-d drawing exemplar has also been amended.

A final area of confusion is the way some stage names have changed, and this again has the biggest impact around Stages 3 and 4 in comparison with the old Stages D, E and F. Stage D used to be Design Development, Stage E was Technical Design and Stage F was Production Information. In the new scheme, Stage 3 is Developed Design and Stage 4 is Technical Design.

The new project stages will take some getting used to – BSRIA has presented a webinar on the changes and this can be accessed from the Webinars page on the BSRIA website.

BG 06/2014 – Design Framework for Building Services is now available in hardcopy, PDF, single license or multi-site license.

UK Budget response from Andrew Eastwell, BSRIA Chief Executive

Andrew Eastwell, BSRIA CEO

Andrew Eastwell, BSRIA CEO

In a budget that is so close to an election there was never going to be pain inflicted that would upset the electorate and so measures required to compel anyone to spend money on energy saving was not going to feature in the Chancellor’s speech.   On the contrary, with Labour repeating their pledge to freeze energy prices the likelihood was that taxes on energy would be reduced – and with it the inevitable consequence that payback times on energy saving measures would become longer.

This is indeed what happened where the Chancellor quoted a figure for reduction of national energy costs of £7bn through a £1bn “special protection” aimed mainly at manufacturers with high energy intensity operations, steel mills, paper producers and chemical manufacturers. This package is intended to “protect… from the rising costs of the Renewable Obligation and Feed-in-Tariffs”.

A freezing of the Carbon Price Floor does also have a small benefit to householders – estimated at £15 per year.

One surprise however was a concession given to CHP which now has an exemption from the Carbon Price Floor for electricity generated.  It is aimed mainly at manufacturers using this technology but presumably will benefit other district schemes as well.

The Chancellor indicated that there would not be a reduction in renewable energy investment but since so much of that is driven by private investor money it remains to be seen how they will react to the plain intent to begin to offset the differential between UK energy prices and those in the USA.  Mr Osborne noted industrial energy costs were half the price in the USA compared to UK.

Elsewhere the statements regarding the efforts to increase house building were largely a restatement of previous announcements such as the proposed new garden city at Ebbsfleet and additional housing in Barking and Brent Cross.  What was intriguing was a proposal to give individuals a new “Right to Build” – backed with £150m of finance. The details of that will be interesting indeed as previous ministers with construction responsibilities have been keen to increase the volume of self-build homes.

Overall the budget did have a feel of being “Northern friendly” with reference to earlier consideration of HS2 construction beyond  its current plan, extension of enterprise zone tax breaks for a further three years and £270m to guarantee funding for the Mersey Gateway bridge.

Certainly the construction sector will welcome efforts to move the centre of effort further out from the London basin so that resources locked up in people, land and facilities can be fully exploited without the additional costs of working in the hothouse of the South but a budget designed for green development?  I don’t think so, that will have to wait until unpalatable policies can be applied with four years to go before a vote!

The hidden menace of corrosion in heating and cooling systems

Written by Reginald Brown, Senior Consultant at BSRIA

Written by Reginald Brown, Senior Consultant at BSRIA

Most buildings services engineers will have come across a heating or cooling system that has not received water treatment and still appears to function perfectly and another that has apparently been treated but experienced serious corrosion related failures. Why should one be vulnerable and the other not? The answer is that most common metals are subject to corrosion but the rate of corrosion and risk of failure depends on a variety of factors including the chemical and microbiological environment, temperature, flow rate and not least the thickness of the metal.

In many respects water is the ideal heat transfer medium for building services. It has a reasonably high specific heat, is liquid over a convenient temperature range and is non-flammable, non-toxic and freely available. The downside is that water is an electrolyte that facilitates corrosion in metallic pipework and components. One might think that the obvious solution is to use plastic pipework but this can actually increase the risk of corrosion of the corrodible components that remain.In a steel pipework system, the dissolved oxygen in the system water will rapidly be used up as it reacts with the large area of corrodible surface but the loss of metal thickness should be insignificant. In a plastic pipework system there are few corrodible components so oxygen concentration will remain higher for longer and the corrodible materials will continue to corrode at a high rate. This means that almost all water based heating and cooling systems should have some form of water treatment to control corrosion, and it may be even more important in plastic pipework systems.

The usual construction programme for large building projects involves installation and pressure testing of pipework followed by pre-commission cleaning and commissioning several months later. During the gap between pressure testing and pre-commission cleaning the system may be both stagnant and still contaminated with manufacturing and construction residues. This is an ideal environment for the development of biofilm and corrosion.

In traditional steel pipe systems (using BS 1387:1985 or BS EN 10255:2004 medium or heavy grade pipe) this is not too much of a problem. The relatively thick pipe (at least 3.2 mm for 1 inch nominal bore and larger) can tolerate the initial corrosion due to the oxygen in the fill water and biofilm development during subsequent stagnation conditions. Provided the pre-commissioning cleaning is carried out effectively, ideally with a biocide wash prior to chemical cleaning, there should be minimal impact on the lifetime of the system.

Thin wall steel pipes and steel panel radiators may not be so fortunate. The thickness of 25 mm nominal bore thin wall carbon steel pipe is only 1.5 mm while a typical steel panel radiator is only 1.3 mm thick. If the initial corrosion was spread uniformly across the metal surface it would not be problem but what tends to happen is that small patches of the surface become anodic relative to their surroundings and are preferentially corroded leading to rapid localised pitting. If dissolved oxygen levels persist or are replenished due air ingress, continuing additions of fresh water or permeation through non-metallic materials then the pitting can progress to perforation. Components that should last 25 years can be perforated in a few months. This is one of the most frequent types of corrosion failure reported to BSRIA and can result in expensive remedial works even before the building is occupied.

Water treatment chemicals work by inhibiting the corrosion process, either by coating the surface of the metal (anodic inhibitors) or otherwise blocking the corrosion reactions (cathodic inhibitors). However, inhibitors are not the solution to poor closed system design or operational deficiencies and certainly won’t work to best effect in a dirty system i.e. one with a high level of suspended solids and/or biological contamination. Also, the system operation must allow the inhibitors and other water treatment chemical to be maintained at an effective concentration and circulated throughout the year.

In summary, the factors necessary to avoid pitting corrosion of steel components in closed systems are:

  1. Minimise the delay between first fill and pre-commission cleaning.
  2. Carry out effective pre-commission cleaning of the pipework system.
  3. Establish, monitor and maintain effective water treatment and water quality as soon as possible in the life of the system.
  4. Circulate water throughout the system on a daily basis to avoid stagnation.
  5. Avoid ingress of oxygen from inadequate pressurisation or excessive fresh water additions.
What happens in the first few weeks of the system can prevent pipe corrosion like this over the next 25 years

What happens in the first few weeks of the system can prevent pipe corrosion like this over the next 25 years

What happens in the first few weeks of the life of the system will influence its fate over the next 25 years. You can’t easily see what is going on inside a pipe but get it wrong and you could be looking at major remedial works in a tenth of that time.

A detailed discussion of corrosion and the use of inhibitors and other chemicals is contained in BSRIA BG50 Water Treatment for Closed Heating and Cooling Systems. Pre-commissioning cleaning is described in BSRIA BG29 Pre-commission cleaning of pipework systems. Guidance on the monitoring of water quality in closed systems is contained in these documents and BS 8552 Sampling and monitoring of water from building services closed systems – Code of practice.

BSRIA also runs a Pre-commission cleaning of pipework systems training course and provides independent failure investigations for all types of building plant and systems including pipweork corrosion.

This article was first published in Modern Building Services.

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