#gvis – Green Design and Preconstruction
A good array of construction professionals attended our GreenVision event on 8th October 2014. This event focused on Design for Building Performance: New Build and Retrofit and 3 fantastic speakers had been secured to deliver presentations.
Mark Siddall (Principal at LEAP) started the evening by talking about how to avoid the seven major pitfalls that prevent buildings from performing properly. Mark Warner (Sustainability Manager at Leeds Beckett University Estates) followed to talk about his experiences of integrating sustainability into building projects. Finally we closed with a presentation from Dr James Parker (Research Fellow at Leeds Beckett University) who talked about modelling and measuring the performance of a workplace retrofit natural ventilation strategy.
Mark Siddall talked about the projects he has worked on and, as a trustee of the Association of Environment Conscious Building, encouraged delegates to join the organisation – see here. He explained there is a huge performance gap in domestic buildings right across the whole construction industry. A Passivhaus project that Mark designed and managed has been studied by Leeds Beckett University. It was found that these were the First Homes that the researchers had ever found to actually close this aspect of the performance gap. (He noted that even the Passivhaus Standard did not directly address all of the technical requirements that were needed in order to achieve this.) Mark also talked about problems arising from poorly conceived natural ventilation strategies. Why are people closing triple vents in winter he wondered? He suggested that it may be related to comfort and the desire to avoid drafts. Mark also questioned whether Part F of the building regulations are appropriate for noise standards. He cited a literature review that he had undertaken with acoustician Jack Harvie-Clark (Apex Acoustics). They studied results from over 1000 homes. Their analysis highlighted that the Part F recommended household noise levels (for mechanical ventilation) will mean that every other person in the property will be dissatisfied i.e. one in two people. Significant steps are needed to address this not only in legislation but in design and construction processes also. Mark then used the RIBA Plan of Work to help describe how redesigning the design process can assist with more effective and more affordable delivery of building projects. He noted that it is important to get the process right at the start of a project. Mark encouraged delegates to think about good practice performance standards including the Passivhaus Standard, EnerPHit Standard, AECB Silver Standard, and the AECB Carbonlite Retrofit Standard. Mark finished his presentation by explaining he is happy to host meetings with people that are interested in building performance and Passivhaus and desire to know more about these subjects. Additional information can be found on the LEAP practice website here
Mark Warner began by saying these types of events are excellent opportunities for sharing experiences (positive or negative) and getting like-minded people together. Mark explained how we (Leeds Beckett University) want to be the educated client, informing the design team with actual data. Mark described how it has taken 8 years to get sustainability into the University’s corporate strategic plan and it’s important now to prove that it works. Mark talked in detail about problems with specifying recycled content into tenders. He explained we ask for investment appraisals not ‘value engineering’ or cost cutting when looking at energy efficiency. The University has a responsibility to be the social conscience and critic of society (New Zealand Education Act) and using recycled products is very important in closing the loop. The University achieves 90%+ recycled rates on construction projects. Mark explained that some of the supply chain cannot provide information on recycled content of products. Mark’s plea is that everybody starts asking for recycled content in tenders so if lots of major organisations do this they will have to start to listen. Mark confirmed there are 2 Passivhaus townhouses on the Headingley campus. Mark works very closely with the research school when working on tenders. The Portland building is currently undergoing an extensive refurbishment to open up existing vents to naturally ventilate floors. Mark explained it seems to be working well so far but further research is required by Dr James Parker (the next speaker) to validate our design and in use experience. There are still another 7 floors to be refurbished and Mark agreed this echoes what Mark Siddall said previously about highlighting problems early on in a project.
James Parker began by praising Mark Sidall. James talked about a case study on the University Calverley Building which has a 60s built concrete frame. James explained it’s important to remember this building had been very well insulated. Focus was on the top 3 floors to begin with. James explained his department is keen to look at domestic buildings. The study looks at what buildings are made of, internal heat gains and understanding what is inside. Analysis was carried out on overheating and heat gain. Occupancy levels are an important factor and extremes have to be considered such as maximum staff levels and all computers being switched on. James talked about early design analysis and the impact of local shading and heat gain from the sun. James joked that we should build really tall buildings in front of buildings that overheat! James explained the study looks at overheating and different things that can be introduced such as blinds. If you reduce heat gain then you also reduce electricity. James described how an isolated study had taken place on room 1010 which is a busy office that is always occupied. The study had looked at this office on one of the hottest weeks of the year. James stated to be a more informed client you need to understand more. It is really important to test, examine and monitor and to feedback to the design team.
Q and A summary
Observations from the floor included:-
- Concerns about the EPC on existing buildings. Is this still worth the paper it is written on?
- EnerPHit standard uplift and not being comparable
- Is the PH Quality Assurance the best standard?
- How will the CIBSE comfort model affect things?
- Has testing been done on fluid dyanmics?
- You’ve transformed a building into a building that is performing better. It’s important to put your study into perspective.
Mark Warner agreed that the results of the study have been great and the information gleaned will be used in future design. James agreed it is cheaper and easier to deal with issues at the start of a project.
Some slides from the presentation given by Mark Siddall can be found here.
Our next Green Vision event will take place on 12th November 2014 and will focus on Workplace Productivity: The New Business Case for Sustainable Buildings. To hear more about this event and to book your place see here
Author: Donna Lee